ADHD Atten Def Hyp Disord DOI 10.1007/s12402-014-0135-0
ORIGINAL ARTICLE
Factors associated with a positive occupational outcome during long-term central stimulant treatment in adult ADHD Terje Torgersen • Steinar Krokstad Arne E. Vaaler
•
Received: 21 June 2013 / Accepted: 19 March 2014 Ó Springer-Verlag Wien 2014
Abstract There is a lack of long-term studies of central stimulant (CS) treatment in adult attention-deficit/hyperactivity disorder (ADHD), and studies on functional outcomes like occupational status are rare. The current study investigated occupational status in adult ADHD patients before and after long-term CS treatment (median duration of treatment 33 months) and aimed to identify variables associated with improvement in occupational status. The collection of data was based on a naturalistic, retrospective approach using the medical records of a sample of all 117 adult ADHD patients consecutively starting treatment with CS in a specific catchment area in Norway in the period 1997 to May 2005. Most patients did not improve in occupational status during long-term CS treatment. The improved group had significantly higher baseline ADHD symptoms as measured by the general adult ADD symptom checklist (83.7 vs. 76.2, p = 0.024) and had a significantly shorter period from the first contact with adult psychiatry until they got the ADHD diagnosis (11.7 vs. 50.9 months, T. Torgersen (&) A. E. Vaaler Department of Østmarka, St. Olavs Hospital, P.O. Box 3008, 7440 Lade, Trondheim, Norway e-mail: [email protected] T. Torgersen A. E. Vaaler Department of Neuroscience, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway S. Krokstad Department of Public Health and General Practice, The Nord-Trøndelag Health Study, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway S. Krokstad Levanger Hospital, Nord-Trøndelag Health Trust, Levanger, Norway
p = 0.001). The results indicate that long-term CS treatment itself may have limited effect on occupational status in functionally impaired and highly comorbid patients with adult ADHD. A high baseline ADHD symptom level may be related to a superior outcome in occupational status. Keywords Attention-deficit/hyperactivity disorder Adult Central stimulants Occupational outcome
Introduction Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder associated with impairment in several social domains throughout the life span (Murphy and Barkley 1996; Biederman et al. 1993; de Graaf et al. 2008; Safren et al. 2010; Gjervan et al. 2012; Halmoy et al. 2009; Shaw et al. 2012). Prospective, longitudinal studies following clinically referred children with ADHD to young adulthood, the Montreal study (Weiss 1985), the New York study (Mannuzza et al. 1993) and the Milwaukee study (Fischer et al. 2002), have shown that young adults with ADHD are more affected than controls on social domains such as education, occupation and social functioning. A number of functional deficits related to ADHD symptoms are closely linked to the ability to function at work: problems with motor coordination, working memory, planning, anticipation and self-regulation (Adamou et al. 2013). Clinical studies investigating the impact of central stimulant (CS) treatment in childhood and adolescence on outcomes in adulthood have yielded mostly disappointing results (Hechtman et al. 1984; Jensen et al. 2007; Molina et al. 2007; Satterfield et al. 2007). Two Norwegian crosssectional studies on clinically referred adults with ADHD
123
T. Torgersen et al.
showed an association between treatment with CS in childhood and participation in working life as adults (Halmoy et al. 2009; Gjervan et al. 2012). A meta-analysis of six studies following children with ADHD into adolescence or adulthood found that CS treatment almost halved the risk of developing substance use disorders (SUD) (Wilens 2003). However, Biederman and colleagues found no such association in a 10-year follow-up study (Biederman et al. 2008). Adult patients with ADHD clinical studies indicate satisfactory short-term efficacy of CS treatment, and metaanalyses comparing methylphenidate (MPH) to placebo have found effect sizes between 0.42 and 0.9 (Koesters et al. 2009; Faraone and Glatt 2010). A number of openlabel long-term studies show that continued CS treatment has lasting effect on symptoms in adult ADHD patients (Bejerot et al. 2010; Wender et al. 2011; Lensing et al. 2013; Goodman 2013). In spite of the effect on ADHD symptoms, there is evidence for residual symptoms and long-lasting functional impairment in many CS-treated adult ADHD patients (Safren et al. 2010; Lensing et al. 2013). Studies investigating occupational outcomes of CS treatment in adult ADHD are generally lacking (Fredriksen et al. 2013; Kupper et al. 2012). A systematic review of long-term outcomes in ADHD found that among nine outcome categories, ‘‘occupation’’ exhibited the least effect of treatment (Shaw et al. 2012). However, in a doubleblind, placebo-controlled study of OROS-MPH active treatment significantly improved self-reported feelings and behaviors contributing to work productivity and efficiency (Buitelaar et al. 2011). Another placebo-controlled study of lisdexamfetamine in a simulated work environment showed improved work performance with active treatment (Wigal et al. 2010). Two previous papers have published data from the present sample suggesting very low levels of education and employment among adult ADHD patients (mean age 28 years) in Nord-Trøndelag County, Norway (Torgersen et al. 2012, 2013). Most patients received their income from social welfare benefits; only 21 patients out of the total sample of 117 (17.9 %) were employed or students at baseline. These numbers are in line with or slightly lower than other Norwegian samples of adult ADHD (Halmoy et al. 2009; Rasmussen and Levander 2009; Gjervan et al. 2012; Lensing et al. 2013). Level of educational achievement was also low, and only 25 patients (21.4 %) had attained senior high school at the age of 28, indicating that almost 80 % could be defined as high school dropouts. These figures differ considerably from the results in a recently published epidemiological study from NordTrøndelag County showing that 17 % of the total youth population was registered as high school dropouts at the
123
age of 24 (De Ridder et al. 2012). This study further showed that the 5-year risk of receiving medical and nonmedical social security benefits was 44 % in the high school dropout group compared with 16 % in the group of high school completers. The authors also found that most of the patients who received medical social security benefits in early adulthood (age 19–23) also received benefits when they were aged 24–28 years, indicating that receiving social security benefits in young adulthood is an important risk factor for persisting working life integration problems. The previous papers from the present sample (N = 117) showed that long duration of CS treatment was predicted positively by the use of extended release formulations of MPH (Torgersen et al. 2012, 2013). Antisocial personality disorder and substance use disorder were related to a shorter duration of CS treatment. Because this was a retrospective, naturalistic study using medical records as source of information it was difficult to collect outcome measures of the effect of treatment on ADHD symptoms and associated emotional symptoms. Good effect on symptoms and quality of life was often described in the records, but not in a systematic and scientifically useful manner. Occupational status was therefore the only outcome measure available at follow-up, except from duration of treatment described in the previous papers (Torgersen et al. 2012, 2013). The aim of the current study was to measure occupational status in adult ADHD patients before and after longterm CS treatment (median length of CS treatment 33 months), using the following categories: employed or student, receiving temporary social security benefits and receiving long-term disability benefits. The study also aimed to identify variables associated with improvement in occupational status during long-term CS treatment.
Methods Setting Study patients were included after admittance to the Department of Psychiatry, Levanger Hospital. This is a local hospital with a catchment area of 90,000 inhabitants living in small towns and rural districts in central Norway. The Department of Psychiatry consists of several inpatient and outpatient units. The patients in the study were assessed and treated at three out-patients units: a unit for general psychiatry, a unit for SUD and a unit for disorders such as autism, Tourette syndrome, ADHD and mental retardation. In the period 1997 to May 2005, it was required that CS treatment of Norwegian ADHD patients older than 18 years had to be approved by a Regional Expert Committee for Hyperkinetic Disorders (RECHD). Under strict
Factors associated with a positive occupational outcome
control by the health authorities, national guidelines were issued and a system to secure adequate diagnosis, treatment and follow-up was initiated. This system for assessment and treatment of adult ADHD is described in earlier papers (Torgersen et al. 2012; Halmoy et al. 2009; Rasmussen and Levander 2009). Subjects The inclusion criteria were as follows: (1) an ADHD diagnosis according to the International Classification of Diseases, 10th revision (ICD-10), Criteria for research (World Health Organization 1992) after an assessment by an experienced psychiatrist at Levanger Hospital; (2) a confirmation of the diagnosis by the RECHD; and (3) commencement of CS treatment as adults. Initially, there were 119 adult patients who consecutively met the inclusion criteria in the study period from 1997 to May 2005. Two patients did not want to participate, which resulted in a final sample of 117 patients, 32 women and 85 men.
treatment, and in many cases also a period after initiation of treatment. Abstinence was in most cases documented by the use of urine tests twice weekly at the office of the general practitioner. In the follow-up period, the patient was seen by the clinician with individual time intervals depending on the patient’s individual needs and wishes. The median number of out-patient consultations the first year after starting CS treatment was 7 (range 0–34). Ethics The Regional Ethical Committee and the Ministry of Health and Care Services have approved the study. The Ministry of Health and Care Services gave permission for only one psychiatrist to read the medical records and collect the data. The patients were informed by postal mail about the study and were given the opportunity not to participate. Procedure for data collection
Clinical assessments at the hospital The national guidelines included systematic assessment of ADHD according to the ICD-10 Criteria for research. Two modifications were made: it was allowed for the inattentive subtype according to Diagnostic and Statistical Manual of Mental Disorders, Fourth edition (DSM-IV) (American Psychiatric Association 1994) to be sufficient for the diagnosis, and it was allowed for the presence of comorbid psychiatric disorders, as long as the diagnostic symptoms of ADHD were present before the appearance of the comorbid disorder. This diagnostic assessment strategy was chosen as a compromise between the fact that ICD-10 is the official diagnostic system used in Norway and the request to have an assessment comparable with the international DSM-IV standards (Halmoy et al. 2009). The requirements of the guidelines included: an evaluation for signs of psychosis, depression, bipolar disorder, anxiety disorders, conduct disorders and SUD; a developmental history confirmed by collateral informants (93.4 % of the cases in the present study: parents 88.4 %, child and adolescence psychiatry (CAP) 30.8 %); a physical examination, blood tests and electrocardiogram; and completion of the two self-report inventories Symptom Checklist 90-items (SCL-90) (Derogatis et al. 1974) and the general adult ADD symptom checklist (GAASC) (Amen 1997). A report with all the information was sent to the RECHD for a definitive conclusion, and the clinicians were not allowed to start CS treatment without a recommendation from the committee. The patients were required to document at least 3 months of abstinence from SUD before initiating CS
The data were collected from the medical records by an experienced psychiatrist (first author). A list of essential variables was made before data collection. Baseline was set to the time the patients started CS treatment as adults. The first patients were included in 1998, and the lasts patients were included in May 2005. The date of follow-up was December 31, 2008, 43 months after inclusion of the last patients. For patients who had terminated treatment before this date, follow-up was set at the date of last contact with the patient documented in the medical records. Outcomes Occupational status at baseline and follow-up was measured using the following categories: (1) employed or student, (2) receiving temporary social security benefits and (3) receiving long-term disability benefits. The first group included patients having their income from ordinary work or students without any kind of social security benefits. The second group had their income from temporary social security benefits, such as social assistance, rehabilitation allowance, sick leave and vocational rehabilitation. The third group, receiving disability benefits, included patients who received a long-term disability pension without any activity or requirement for treatment or rehabilitation. Normally, these patients had received temporary social security benefits for years before being granted a disability benefit. Improvement in occupational status was defined as a change in main income from temporary social security benefits or disability benefits to employment or studies
123
T. Torgersen et al.
from baseline to follow-up (improved group). The group of patients without such improvement is the not improved group. These groups were compared with a number of variables. At baseline self-reported ADHD symptoms (GAASC), self-reported general psychiatric symptoms (SCL-90), criminality, educational level, comorbidity with SUD and personality disorders, and childhood treatment were assessed. A comorbid disorder was diagnosed only if the medical records clearly confirmed the criteria for a DSM-IV diagnosis. The GAASC version used in the present study is a 29-items list of hyperkinetic symptoms with five subscales: attention, impulsivity, restlessness, organization and executive function. The items are measured on a 5-point scale (0–4: never, seldom, sometimes, often and very often). At follow-up, aspects of CS treatment in adulthood were assessed: duration of CS treatment, maintenance dose of CS, duration from first contact with adult psychiatry to diagnosis of ADHD, number of out-patient consultations the first year of CS treatment and the number of patients who changed from one type of CS to another. Information about maintenance dose was collected only for MPH, because this was the main CS drug used by the patients. The CS treatment given is described in detail in a previous paper (Torgersen et al. 2012).
\18 years. The sample was highly comorbid, and there were significant gender differences for antisocial and borderline personality disorders. In the male group, 47.1 % had one or more criminal sentences. These frequencies were significantly lower among females. The most important characteristics, total and by gender, are presented in Table 1. Occupational status at baseline and follow-up At baseline, 77 patients received temporary social security benefits. At follow-up, only 11 patients (14.3 %) in this group had improved their status to employee or student. Thirty-three patients (42.9 %) had a negative development into long-term disability pension, and 33 patients (42.9 %) were still receiving temporary social security benefits. Among the 21 patients who were employed or students at baseline, seven (33.4 %) had a negative development and received a social security benefit at follow-up. At baseline, the group employed or student consisted of 21 patients, 11 employees and 10 students. At follow-up, this group consisted of 25 patients, 20 employees and 5 students. Among the 19 patients who were receiving disability pension at baseline, none improved their occupational status to employee or student at follow-up (Table 2). Improvement in occupational status
Statistics Gender differences in baseline sociodemographic and clinical characteristic and differences between the improved and not improved groups were analyzed by the use of v2 test and Fisher exact test for categorical variables and T test for continuous variables. The data were analyzed by the SPSS (Statistical Package for the Social Sciences, version 17; IBM Corporation, Armonk, NY).
Results Baseline sociodemographic and clinical characteristics The sample consists of 117 patients, predominantly men (72.6 %) with ADHD combined subtype. Mean age when starting CS treatment was 28.6 years (women 30.1, men 28.1). A majority of the patients (60.7 %) had been in contact with Pedagogical and Psychological Services (PPS) in childhood. Half of these (30.8 %) had been treated in CAP, but only 18.8 % had been diagnosed with ADHD at an age \18 years, and 14.5 % had received CS treatment before this age. Level of educational achievement was very low, and only 21.4 % had finished senior high school. There were no significant differences between genders with regard to age, subtype, educational level or CS treatment at an age
123
The 11 patients in the improved group (improved their status from social benefits to work or study) were compared to the not improved group. There was a significant difference in baseline ADHD symptoms as measured by the GAASC, showing higher level of baseline symptoms in the improved group. When analyzing subscales of the GAASC, we found significant differences in impulsivity and organization. The improved group had also a nonsignificant trend toward lower levels of psychiatric symptoms according to SCL-90 Global Severity Index (1.3 vs. 1.6). The improved group had a significantly shorter period from the first contact with adult psychiatry until they got the ADHD diagnosis (11.7 vs. 50.9 months, p \ 0.001). They also had a nonsignificant trend toward longer duration of CS treatment (47.2 vs. 32.4 months) and higher maintenance dose of MPH (65.5 vs. 58.2 mg/day). There were no significant differences between the groups considering baseline age, gender, criminality, educational level or comorbidity. For details, see Table 3.
Discussion In the present study, we found that few patients with adult ADHD improved in occupational status during long-term CS treatment despite adequate doses (Koesters et al. 2009;
Factors associated with a positive occupational outcome Table 1 Baseline sociodemographic and clinical characteristics, total and by gender, in the sample of adult ADHD patients (N = 117)
Gender Age (mean/SD)
Total
%
117
100
28.6
Women
7.6
32 30.1
% 27.4 9.3
Men
%
85
72.6
28.1
p
6.9
0.265c
112
95.7
29
90.6
83
97.6
0.094a
Contact with PPT
71
60.7
18
56.3
53
62.4
0.547b
Treatment in CAP
36
30.8
7
21.9
29
34.1
0.201b
ADHD
22
18.8
3
9.4
19
22.4
0.270a
CD or ODD
13
11.1
3
9.4
10
11.8
0.679a
6
5.1
1
3.1
5
5.9
0.851a
17
14.5
1
3.1
16
18.8
0.052a
Finished junior high school
112
95.7
32
100.0
80
94.1
0.161b
Finished senior high school
25
21.4
3
9.4
22
25.9
0.052b
Employed or student One or more criminal sentence
21 44
17.9 37.6
4 4
12.5 12.5
17 40
20.0 47.1
0.346b 0.001b
Mental retardation
5
4.3
1
3.1
4
4.7
0.706a
Learning disability
15
12.8
5
15.6
10
11.8
0.578a
Asperger syndrome
3
2.6
0
3
3.5
0.282a
Tourette syndrome
5
4.3
2
3
3.5
0.517a
Schizophrenia
2
1.7
0
2
2.4
Alcohol
55
47.0
12
37.5
43
50.6
0.206b
Cannabis
49
41.9
10
31.3
39
45.9
0.153b
Amphetamine
48
41.0
9
28.1
39
45.9
0.082b
Opiates
14
12.0
1
3.1
13
15.3
0.071a
Lifetime major depression
38
32.4
12
37.5
26
30.6
0.477b
Bipolar disorder, type I
4
3.4
2
6.3
2
2.4
0.301a
Bipolar disorder, type II
8
6.8
5
15.6
3
3.5
0.505a
35 13
29.9 11.1
3 9
9.4 28.1
32 4
37.6 4.7
0.003b 0.001b
ADHD combined subtype Childhood diagnoses and treatment
Diagnoses in CAP
Learning disability CS treatment in childhood Functional impairment at baseline
Comorbid disorders at baseline
6.3
Lifetime substance use disorders
CAP child and adolescence psychiatry, PPT pedagogical and psychological service in school, CS central stimulant, CD conduct disorder, ODD oppositional defiant disorder a
Fisher exact test
b
v2 test
c
T test
Antisocial personality disorder Borderline personality disorder
Faraone and Glatt 2010; Torgersen et al. 2008; Wender et al. 2011; Reimherr et al. 2007) and duration of treatment. This does not indicate that the patients did not improve in symptoms or quality of life, but due to the retrospective, naturalistic approach using medical records as the source of information it was difficult to collect additional outcome measures such as ADHD symptoms or associated emotional symptoms at follow-up. Good clinical effect on symptoms was often described in the records, but not in a systematic and scientifically useful manner. Occupational status was the only outcome measure available at follow-up except from duration of treatment described in the previous papers (Torgersen et al. 2012, 2013). Due to the small number of patients in the improved group (11 patients, 9.4 % of the total sample), we assumed limited possibilities to find significant differences between
the improved and not improved group. However, the improved group had significantly higher baseline level of ADHD symptoms compared with the group that did not improve. The improved group also had lower levels of general psychiatric symptoms as measured by SCL-90, but this difference did not reach statistical significance. This may be due to the small numbers. It is possible that the patients with a more ‘‘pure ADHD’’ had better effects of CS treatment on functional outcomes such as occupational status. Buitelaar and colleagues (Buitelaar et al. 2011) argues that greater baseline severity may reflect a more homogeneous and biologically based ADHD subtype, which may respond more strongly to dopamine-enhancing therapy. We also found nonsignificant trends toward longer CS treatment duration and higher maintenance dose of MPH in the improved group. We cannot exclude that the
123
T. Torgersen et al. Table 2 Occupational status at baseline and at follow-up. Median follow-up time was 33 months (N = 117) Baseline
Follow-up
Disability benefits
Disability benefits
18
94.7
N = 19
Temporary social security benefits
1
5.3
19 33
100.0 42.9
Temporary social security benefits
33
42.9
Employed or student
11
14.3
77
100.0
Temporary social security benefits N = 77
Employed or student (no social security benefits) N = 21
Disability benefits
%
Disability benefits
1
4.8
Temporary social security benefits
6
28.6
14 21
66.7 100.0
Employed or student N = 117
N
117
improved group received a more intensive CS treatment for a longer duration than the not improved group resulting in occupational improvement. An alternative explanation is that longer treatment duration and higher MPH dosages may be due to better perceived effect of the treatment and/ or a greater tolerance for stimulants. The finding in the present study is in accordance with recent controlled studies of CS treatment in adult ADHD. A study by Buitelaar and colleagues (Buitelaar et al. 2011) investigated predictors of response in adults with ADHD randomly assigned to osmotic release oral system (OROS)MPH 18, 36 or 72 mg or placebo. The study comprised a 5-week, double-blind period followed by a 7-week, openlabel period. The results showed that a higher baseline level of ADHD symptoms was the strongest predictor of a superior outcome in symptoms as measured by Conners’ Adult ADHD Rating Scale (CAARS). Male gender and lower academic achievement were also predictive for a superior outcome. Another study examined the impact of baseline ADHD symptom severity on lisdexamfetamine dimesylate (LDX) efficacy in a long-term study of adults with ADHD (Ginsberg et al. 2011). Adults from a 4-week, placebocontrolled, forced dose-escalation study with LDX (30–70 mg/day) or placebo were enrolled in a long-term, open-label dose-optimization study for an additional 12 months. Participants were stratified by baseline severity (from the prior short-term study) with Clinical Global Impressions-Severity (CGI-S) scores of 4 (moderately), 5 (markedly) or C6 (severely/extremely ill). Long-term LDX treatment demonstrated increased degree of symptom improvement with greater baseline symptom severity.
123
Table 3 Comparing baseline characteristics for patients that improved and not improved occupational status in the follow-up period (N = 117) Improved N = 11 Women (N, %) 2 18.2 Age at baseline (mean/SD) 28.7 6.9 Baseline self-reported symptoms (mean/SD) SCL-90, global severity Index 1.3 0.8 GAASC total 83.7 7.3 GAASC subscale attention 3.2 0.5 GAASC subscale impulsivity 2.8 0.4 GAASC subscale restlessness 3.2 0.6 GAASC subscale organization 2.9 0.5 GAASC subscale executive 2.8 0.8 function Baseline self-reported criminal activity (N, %) One or more criminal sentences 2 18.2 Two or more types of sentence 1 9.1 Sentence for violence 0 Sentence for theft 0 Sentence for drug-related crime 1 9.1 Sentence for drunk driving 2 18.2 Baseline education (N, %) Finished senior high school 2 18.2 Baseline lifetime comorbid disorders (N, %) Alcohol use disorder 4 36.4 Amphetamine use disorder 5 45.5 Cannabis use disorder 4 36.4 Opioid use disorder 0 Borderline personality disorder 1 9.1 Antisocial personality disorder 2 18.2 Major depression 4 36.4 Treatment in childhood (N, %) Contact with PPT 4 36.4 Diagnosis of ADHD in CAP 2 18.2 Treatment with CS in CAP 2 18.2 Treatment in adulthood (mean/SD) Months in CS treatment 47.2 27.7 MPH maintenance dose in 65.5 15.1 mg/d Months from first contact AP to 11.7 13.7 diagnosis of ADHD Number of out-patient 9.5 8.3 consultations the 1 year Changing type of CS (N, %) 8 72.7
Not improved N = 106
p
30 28.6
28.3 7.7
0.725a 0.972c
1.6 76.2 3.0 2.4 2.7 2.5 2.6
0.8 17.4 0.6 0.7 0.9 0.8 0.8
0.312c 0.024c 0.251c 0.006c 0.125c 0.047c 0.369c
42 25 25 22 12 19
39.6 23.6 23.6 20.8 11.3 17.9
0.205a 0.452a 0.117a 0.122a 1.000a 1.000a
23
21.7
1.000a
51 43 45 14 12 33 34
48.1 40.6 42.5 13.2 11.3 31.1 32.1
0.457b 0.758a 0.759a 0.356a 1.000a 0.502 0.746a
67 20 15
63.2 18.9 14.2
0.108a 1.000a 0.593a
32.4 58.2
27.9 22.6
0.097c 0.300c
50.9
64.3
0.001c
8.4
7.3
0.619c
53
50.0
0.151
SCL-90 symptom checklist 90 items, GAASC general adult ADD symptom checklist, CAP child and adolescence psychiatry, PPT pedagogical and psychological service in school, CS central stimulant, MPH methylphenidate, AP adult psychiatry a Fisher exact test b 2 v test c T test
Factors associated with a positive occupational outcome
Rates of clinical response and symptomatic remission tended to increase with greater baseline severity. The finding that a larger proportion of patients with greater baseline symptom severity have a more ‘‘pure ADHD’’ with better effect of treatment compared with patients with less severe symptoms might explain these findings. Another major finding in the present study was that the improved group had a significantly shorter period from the first contact with adult psychiatry until they got the ADHD diagnosis (11.7 vs. 50.9 months, p = 0.001). The finding that the not improved group had been treated significantly longer in adult psychiatry before getting the ADHD diagnosis probably reflects a more chronic course of mental illness with substantial comorbidity. This negative effect of a more chronic course of mental illness on occupational outcome is recently demonstrated in depressive disorder (Trivedi et al. 2013). The study included out-patients (N = 1928) treated with antidepressants. The important finding was that patients who demonstrated initial treatment resistance were more prone to persistent impairment in occupational productivity than patients experiencing initial response to treatment. Adult ADHD patients with a high level of chronic psychiatric comorbidity and functional impairment may represent a more heterogeneous group of ADHD patients. It is to be expected less effect of stimulant therapy alone due to the substantial part of the variation in functional impairment explained by the comorbid disorders and not ADHD. The finding that few patients improved in occupational status during long-term CS treatment in the present clinical sample may have several causes. The low percentage of employed or students at baseline are in line with or slightly lower than other Norwegian studies on clinical samples of adult ADHD showing employment rates at 22–24 % (Halmoy et al. 2009; Gjervan et al. 2012; Rasmussen and Levander 2009). The rates from Norwegian studies on adult ADHD are surprisingly close to the corresponding rates of 10–20 % in chronic schizophrenia (Tandberg et al. 2012; Marwaha and Johnson 2004), which indicates the severity of the disease in terms of functional impairment. The employment rate in the general adult population in Norway is about 75 % (OECD 2012). The low academic achievement will make it more difficult for the patients to attend work in contemporary Norwegian working life. The high level of criminality measured at baseline can also contribute to problems regarding working life integration and occupational functioning. Further, the patients had predominantly the combined subtype of ADHD, and most studies have showed more symptoms and functional impairment in this subtype than the others (Wilens et al. 2009). In the present clinical sample of adult ADHD patients, the levels of comorbidity with SUD and antisocial
personality disorder were higher than other Norwegian studies (Gjervan et al. 2012; Halmoy et al. 2009; Rasmussen and Levander 2009), European and US (Biederman et al. 1993; Sobanski et al. 2007; Cumyn et al. 2009; Barkley et al. 2008). Level of comorbidity was much higher than most controlled studies of CS treatment in adult ADHD (Torgersen et al. 2008; Peterson et al. 2008). The high level of comorbidity is also a probable cause of the limited improvement in occupational status. Previous studies have shown that ADHD with comorbidities such as depression, anxiety, severe personality disorders and SUD has more negative impact on occupational function than ADHD without comorbidity (Sobanski et al. 2007; Weiss and Hechtman 2006). In an epidemiological study from Nord-Trøndelag County, De Ridder and colleagues (De Ridder et al. 2012) found that 66 % of the persons who had received social security benefits in early adulthood (aged 19–23) also received benefits in a later period (aged 24–28). Data from studies in patients with low back pain have suggested that prolonged duration of disability and sick leave makes return to work more unlikely (Airaksinen et al. 2006). For patients with low back pain, 6 months of sick leave reduces the possibility of returning to work to under 50 %, and after 2 years of sick leave, the probability of returning to work is very low (Waddell and Burton 2005). These results indicate that receiving social security benefits in young adulthood is a phenomenon that persists over time regardless of diagnosis. How the health services and the social security system works, facing the lack of improvement in occupational status for the clients, may play a role in this context. Data suggest that a larger proportion of the population in the Scandinavian countries have their income from social benefits due to illnesses compared with most other Western countries. Thus, treatment, social assistance, rehabilitation allowance and vocational rehabilitation have a potential for improvement. However, Norway is still on top internationally regarding employment-to-population ratio (75 % in 2010), which question the value of data showing high rates of social security dependence (OECD 2012). Another explanation of the association between length of benefit receipt and reduced chance of returning to work might simply be that persons on long-term benefit have more (known and unknown) comorbidity and more social problems (Krokstad et al. 2002). CS treatment itself may have limited effect on occupational function despite the efficacy on ADHD symptoms. Safren and colleagues showed that in CS-treated adult patients work and interpersonal problems appear to be the most important areas of life impairments (Safren et al. 2010). Another study of stability of cognitive deficits in adult ADHD showed that such deficits seem to be
123
T. Torgersen et al.
independent of the course of ADHD and therefore may be a chronic work-related problem (Biederman et al. 2009). The present study has limitations that should be considered. It is a naturalistic study, and the patients are diagnosed and treated by different clinicians with heterogeneous experience and competence. This problem is to some extent compensated for by the fact that all clinicians in the department used the semi-structured national guidelines for assessment of adult ADHD and that the RECHD reconsidered all cases. While most controlled studies of CS treatment exclude patients with comorbidities typical for clinical settings, our study included all patients from a catchment area in a limited time period. Still there are many sources of bias associated with the referral procedure. During the first years of this study, the knowledge about adult ADHD was sparse and variable in the Norwegian health care system, among the patients and in the community, and coincidences could thus decide whether a patient was referred to assessment for ADHD by the general practitioner or not. Patients with serious and ongoing comorbidity, or noncompliance to treatment, might never have reached the point where assessment for ADHD was considered. Overall, referral bias is probably present to a lesser degree in our sample than many other studies of CS treatment of adult ADHD. Retrospective collection of data from medical records gives variable amounts and quality of information from one patient to another. Some information, such as sociodemographic data, information about treatment given, and educational and occupational status, are likely to be reliable. The level of comorbidity may be less reliable and can be used mainly to indicate a high level of comorbidity. As in most studies of pharmacological treatment, we cannot be certain about the patient’s adherence to the prescribed treatment. A major weakness of the study is the lack of secondary outcomes, such as measures of ADHD symptoms, general psychiatric symptoms and quality of life at follow-up. These measures could have made it possible to find correlation between CS treatment, changes in symptoms and occupational status. However, the long duration of CS treatment may indicate that the patients experienced the treatment as helpful and meaningful. The results of the present study indicate that long-term CS treatment itself may have limited effect on occupational status in functionally impaired and highly comorbid samples of adult ADHD. This finding underscores the importance of developing additional and more comprehensive treatment methods for the functional impairments related to adult ADHD. However, the results also indicate that a high baseline ADHD symptom level may be related to a superior outcome not only in short-term ADHD symptom relief,
123
but also in functional outcomes such as occupational status. Further research should explore long-term CS treatment more structured using additional outcome measures such as ADHD symptoms and quality of life.
References Adamou M, Arif M, Asherson P, Aw TC, Bolea B, Coghill D et al (2013) Occupational issues of adults with ADHD. BMC Psychiatry 13:59 Airaksinen O, Brox JI, Cedraschi C, Hildebrandt J, Klaber-Moffett J, Kovacs F et al (2006) Chapter 4. European guidelines for the management of chronic nonspecific low back pain. Eur Spine J 15(Suppl 2):S192–S300 Amen DG (1997) General adult ADD symptom checklist. In: Clark CG (ed) ADHD throughout the lifespan. Random Clark, Las Vegas American Psychiatric Association (1994) Diagnostic and statistical manual of mental disorders (DSM-IV), 4th edn. American Psychiatric Association, Washington Barkley RA, Murphy K, Fischer M (2008) Educational and occupational functioning. In: Barkley RA, Murphy K, Fischer M (eds) ADHD in adults. What science says. The Guilford Press, New York, pp 245–290 Bejerot S, Ryden EM, Arlinde CM (2010) Two-year outcome of treatment with central stimulant medication in adult attentiondeficit/hyperactivity disorder: a prospective study. J Clin Psychiatry 71:1590–1597 Biederman J, Faraone SV, Spencer T, Wilens T, Norman D, Lapey KA et al (1993) Patterns of psychiatric comorbidity, cognition, and psychosocial functioning in adults with attention deficit hyperactivity disorder. Am J Psychiatry 150:1792–1798 Biederman J, Monuteaux MC, Spencer T, Wilens TE, Macpherson HA, Faraone SV (2008) Stimulant therapy and risk for subsequent substance use disorders in male adults with ADHD: a naturalistic controlled 10-year follow-up study. Am J Psychiatry 165:597–603 Biederman J, Petty CR, Ball SW, Fried R, Doyle AE, Cohen D et al (2009) Are cognitive deficits in attention deficit/hyperactivity disorder related to the course of the disorder? A prospective controlled follow-up study of grown up boys with persistent and remitting course. Psychiatry Res 170:177–182 Buitelaar JK, Kooij JJ, Ramos-Quiroga JA, Dejonckheere J, Casas M, van Oene JC et al (2011) Predictors of treatment outcome in adults with ADHD treated with OROS(R) methylphenidate. Prog Neuropsychopharmacol Biol Psychiatry 35:554–560 Cumyn L, French L, Hechtman L (2009) Comorbidity in adults with attention-deficit hyperactivity disorder. Can J Psychiatry 54:673–683 de Graaf R, Kessler RC, Fayyad J, ten HM, Alonso J, Angermeyer M et al (2008) The prevalence and effects of adult attention-deficit/ hyperactivity disorder (ADHD) on the performance of workers: results from the WHO World Mental Health Survey Initiative. Occup Environ Med 65:835–842 De Ridder KA, Pape K, Johnsen R, Westin S, Holmen TL, Bjorngaard JH (2012) School dropout: a major public health challenge: a 10-year prospective study on medical and non-medical social insurance benefits in young adulthood, the Young-HUNT 1 Study (Norway). J Epidemiol Community Health 66:995–1000 Derogatis LR, Lipman RS, Rickels K, Uhlenhuth EH, Covi L (1974) The Hopkins Symptom Checklist (HSCL): a self-report symptom inventory. Behav Sci 19:1–15
Factors associated with a positive occupational outcome Faraone SV, Glatt SJ (2010) A comparison of the efficacy of medications for adult attention-deficit/hyperactivity disorder using meta-analysis of effect sizes. J Clin Psychiatry 71:754–763 Fischer M, Barkley RA, Smallish L, Fletcher K (2002) Young adult follow-up of hyperactive children: self-reported psychiatric disorders, comorbidity, and the role of childhood conduct problems and teen CD. J Abnorm Child Psychol 30:463–475 Fredriksen M, Halmoy A, Faraone SV, Haavik J (2013) Long-term efficacy and safety of treatment with stimulants and atomoxetine in adult ADHD: a review of controlled and naturalistic studies. Eur Neuropsychopharmacol 23(6):508–527 Ginsberg L, Katic A, Adeyi B, Dirks B, Babcock T, Lasser R et al (2011) Long-term treatment outcomes with lisdexamfetamine dimesylate for adults with attention-deficit/hyperactivity disorder stratified by baseline severity. Curr Med Res Opin 27:1097–1107 Gjervan B, Torgersen T, Nordahl HM, Rasmussen K (2012) Functional impairment and occupational outcome in adults with ADHD. J Atten Disord 16:544–552 Goodman DW (2013) Sustained treatment effect in attention-deficit/ hyperactivity disorder: focus on long-term placebo-controlled randomized maintenance withdrawal and open-label studies. Ther Clin Risk Manag 9:121–130 Halmoy A, Fasmer OB, Gillberg C, Haavik J (2009) Occupational outcome in adult ADHD: impact of symptom profile, comorbid psychiatric problems, and treatment: a cross-sectional study of 414 clinically diagnosed adult ADHD patients. J Atten Disord 13:175–187 Hechtman L, Weiss G, Perlman T (1984) Young adult outcome of hyperactive children who received long-term stimulant treatment. J Am Acad Child Psychiatry 23:261–269 Jensen PS, Arnold LE, Swanson JM, Vitiello B, Abikoff HB, Greenhill LL et al (2007) 3-year follow-up of the NIMH MTA study. J Am Acad Child Adolesc Psychiatry 46:989–1002 Koesters M, Becker T, Kilian R, Fegert JM, Weinmann S (2009) Limits of meta-analysis: methylphenidate in the treatment of adult attention-deficit hyperactivity disorder. J Psychopharmacol 23:733–744 Krokstad S, Johnsen R, Westin S (2002) Social determinants of disability pension: a 10-year follow-up of 62,000 people in a Norwegian county population. Int J Epidemiol 31:1183–1191 Kupper T, Haavik J, Drexler H, Ramos-Quiroga JA, Wermelskirchen D, Prutz C et al (2012) The negative impact of attention-deficit/ hyperactivity disorder on occupational health in adults and adolescents. Int Arch Occup Environ Health 85:837–847 Lensing MB, Zeiner P, Sandvik L, Opjordsmoen S (2013) Four-year outcome in psychopharmacologically treated adults with attention-deficit/hyperactivity disorder: a questionnaire survey. J Clin Psychiatry 74:e87–e93 Mannuzza S, Klein RG, Bessler A, Malloy P, LaPadula M (1993) Adult outcome of hyperactive boys. Educational achievement, occupational rank, and psychiatric status. Arch Gen Psychiatry 50:565–576 Marwaha S, Johnson S (2004) Schizophrenia and employment—a review. Soc Psychiatry Psychiatr Epidemiol 39:337–349 Molina BS, Flory K, Hinshaw SP, Greiner AR, Arnold LE, Swanson JM et al (2007) Delinquent behavior and emerging substance use in the MTA at 36 months: prevalence, course, and treatment effects. J Am Acad Child Adolesc Psychiatry 46:1028–1040 Murphy K, Barkley RA (1996) Attention deficit hyperactivity disorder adults: comorbidities and adaptive impairments. Compr Psychiatry 37:393–401 OECD (2012) Employment rate % of working age population. OECDiLibrary July 11. doi:10.1787/20752342-table4 Peterson K, McDonagh MS, Fu R (2008) Comparative benefits and harms of competing medications for adults with attention-deficit
hyperactivity disorder: a systematic review and indirect comparison meta-analysis. Psychopharmacology 197:1–11 Rasmussen K, Levander S (2009) Untreated ADHD in adults: are there sex differences in symptoms, comorbidity, and impairment? J Atten Disord 12:353–360 Reimherr FW, Williams ED, Strong RE, Mestas R, Soni P, Marchant BK (2007) A double-blind, placebo-controlled, crossover study of osmotic release oral system methylphenidate in adults with ADHD with assessment of oppositional and emotional dimensions of the disorder. J Clin Psychiatry 68:93–101 Safren SA, Sprich SE, Cooper-Vince C, Knouse LE, Lerner JA (2010) Life impairments in adults with medication-treated ADHD. J Atten Disord 13:524–531 Satterfield JH, Faller KJ, Crinella FM, Schell AM, Swanson JM, Homer LD (2007) A 30-year prospective follow-up study of hyperactive boys with conduct problems: adult criminality. J Am Acad Child Adolesc Psychiatry 46:601–610 Shaw M, Hodgkins P, Caci H, Young S, Kahle J, Woods AG et al (2012) A systematic review and analysis of long-term outcomes in attention deficit hyperactivity disorder: effects of treatment and non-treatment. BMC Med 10:99 Sobanski E, Bruggemann D, Alm B, Kern S, Deschner M, Schubert T et al (2007) Psychiatric comorbidity and functional impairment in a clinically referred sample of adults with attention-deficit/ hyperactivity disorder (ADHD). Eur Arch Psychiatry Clin Neurosci 257:371–377 Tandberg M, Ueland T, Andreassen OA, Sundet K, Melle I (2012) Factors associated with occupational and academic status in patients with first-episode psychosis with a particular focus on neurocognition. Soc Psychiatry Psychiatr Epidemiol 47: 1763–1773 Torgersen T, Gjervan B, Rasmussen K (2008) Treatment of adult ADHD: is current knowledge useful to clinicians? Neuropsychiatr Dis Treat 4:177–186 Torgersen T, Gjervan B, Nordahl HM, Rasmussen K (2012) Predictive factors for more than 3 years’ duration of central stimulant treatment in adult attention-deficit/hyperactivity disorder: a retrospective, naturalistic study. J Clin Psychopharmacol 32:645–652 Torgersen T, Gjervan B, Rasmussen K, Vaaler A, Nordahl HM (2013) Prevalence of comorbid substance use disorder during long-term central stimulant treatment in adult ADHD. Atten Defic Hyperact Disord 5:59–67 Trivedi MH, Morris DW, Wisniewski SR, Lesser I, Nierenberg AA, Daly E et al (2013) Increase in work productivity of depressed individuals with improvement in depressive symptom severity. Am J Psychiatry 170:633–641 Waddell G, Burton AK (2005) Concepts of rehabilitation for the management of low back pain. Best Pract Res Clin Rheumatol 19:655–670 Weiss G (1985) Hyperactivity. Overview and new directions. Psychiatr Clin N Am 8:737–753 Weiss M, Hechtman L (2006) A randomized double-blind trial of paroxetine and/or dextroamphetamine and problem-focused therapy for attention-deficit/hyperactivity disorder in adults. J Clin Psychiatry 67:611–619 Wender PH, Reimherr FW, Marchant BK, Sanford ME, Czajkowski LA, Tomb DA (2011) A one year trial of methylphenidate in the treatment of ADHD. J Atten Disord 15:36–45 Wigal T, Brams M, Gasior M, Gao J, Squires L, Giblin J (2010) Randomized, double-blind, placebo-controlled, crossover study of the efficacy and safety of lisdexamfetamine dimesylate in adults with attention-deficit/hyperactivity disorder: novel findings using a simulated adult workplace environment design. Behav Brain Funct 6:34
123
T. Torgersen et al. Wilens TE (2003) Does the medicating ADHD increase or decrease the risk for later substance abuse? Rev Br Psiquiatr 25:127–128 Wilens TE, Biederman J, Faraone SV, Martelon M, Westerberg D, Spencer TJ (2009) Presenting ADHD symptoms, subtypes, and
123
comorbid disorders in clinically referred adults with ADHD. J Clin Psychiatry 70:1557–1562 World Health Organization (1992) International classification of diseases, 10th revision. Criteria for research, Geneva
ORIGINAL ARTICLE
Factors associated with a positive occupational outcome during long-term central stimulant treatment in adult ADHD Terje Torgersen • Steinar Krokstad Arne E. Vaaler
•
Received: 21 June 2013 / Accepted: 19 March 2014 Ó Springer-Verlag Wien 2014
Abstract There is a lack of long-term studies of central stimulant (CS) treatment in adult attention-deficit/hyperactivity disorder (ADHD), and studies on functional outcomes like occupational status are rare. The current study investigated occupational status in adult ADHD patients before and after long-term CS treatment (median duration of treatment 33 months) and aimed to identify variables associated with improvement in occupational status. The collection of data was based on a naturalistic, retrospective approach using the medical records of a sample of all 117 adult ADHD patients consecutively starting treatment with CS in a specific catchment area in Norway in the period 1997 to May 2005. Most patients did not improve in occupational status during long-term CS treatment. The improved group had significantly higher baseline ADHD symptoms as measured by the general adult ADD symptom checklist (83.7 vs. 76.2, p = 0.024) and had a significantly shorter period from the first contact with adult psychiatry until they got the ADHD diagnosis (11.7 vs. 50.9 months, T. Torgersen (&) A. E. Vaaler Department of Østmarka, St. Olavs Hospital, P.O. Box 3008, 7440 Lade, Trondheim, Norway e-mail: [email protected] T. Torgersen A. E. Vaaler Department of Neuroscience, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway S. Krokstad Department of Public Health and General Practice, The Nord-Trøndelag Health Study, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway S. Krokstad Levanger Hospital, Nord-Trøndelag Health Trust, Levanger, Norway
p = 0.001). The results indicate that long-term CS treatment itself may have limited effect on occupational status in functionally impaired and highly comorbid patients with adult ADHD. A high baseline ADHD symptom level may be related to a superior outcome in occupational status. Keywords Attention-deficit/hyperactivity disorder Adult Central stimulants Occupational outcome
Introduction Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder associated with impairment in several social domains throughout the life span (Murphy and Barkley 1996; Biederman et al. 1993; de Graaf et al. 2008; Safren et al. 2010; Gjervan et al. 2012; Halmoy et al. 2009; Shaw et al. 2012). Prospective, longitudinal studies following clinically referred children with ADHD to young adulthood, the Montreal study (Weiss 1985), the New York study (Mannuzza et al. 1993) and the Milwaukee study (Fischer et al. 2002), have shown that young adults with ADHD are more affected than controls on social domains such as education, occupation and social functioning. A number of functional deficits related to ADHD symptoms are closely linked to the ability to function at work: problems with motor coordination, working memory, planning, anticipation and self-regulation (Adamou et al. 2013). Clinical studies investigating the impact of central stimulant (CS) treatment in childhood and adolescence on outcomes in adulthood have yielded mostly disappointing results (Hechtman et al. 1984; Jensen et al. 2007; Molina et al. 2007; Satterfield et al. 2007). Two Norwegian crosssectional studies on clinically referred adults with ADHD
123
T. Torgersen et al.
showed an association between treatment with CS in childhood and participation in working life as adults (Halmoy et al. 2009; Gjervan et al. 2012). A meta-analysis of six studies following children with ADHD into adolescence or adulthood found that CS treatment almost halved the risk of developing substance use disorders (SUD) (Wilens 2003). However, Biederman and colleagues found no such association in a 10-year follow-up study (Biederman et al. 2008). Adult patients with ADHD clinical studies indicate satisfactory short-term efficacy of CS treatment, and metaanalyses comparing methylphenidate (MPH) to placebo have found effect sizes between 0.42 and 0.9 (Koesters et al. 2009; Faraone and Glatt 2010). A number of openlabel long-term studies show that continued CS treatment has lasting effect on symptoms in adult ADHD patients (Bejerot et al. 2010; Wender et al. 2011; Lensing et al. 2013; Goodman 2013). In spite of the effect on ADHD symptoms, there is evidence for residual symptoms and long-lasting functional impairment in many CS-treated adult ADHD patients (Safren et al. 2010; Lensing et al. 2013). Studies investigating occupational outcomes of CS treatment in adult ADHD are generally lacking (Fredriksen et al. 2013; Kupper et al. 2012). A systematic review of long-term outcomes in ADHD found that among nine outcome categories, ‘‘occupation’’ exhibited the least effect of treatment (Shaw et al. 2012). However, in a doubleblind, placebo-controlled study of OROS-MPH active treatment significantly improved self-reported feelings and behaviors contributing to work productivity and efficiency (Buitelaar et al. 2011). Another placebo-controlled study of lisdexamfetamine in a simulated work environment showed improved work performance with active treatment (Wigal et al. 2010). Two previous papers have published data from the present sample suggesting very low levels of education and employment among adult ADHD patients (mean age 28 years) in Nord-Trøndelag County, Norway (Torgersen et al. 2012, 2013). Most patients received their income from social welfare benefits; only 21 patients out of the total sample of 117 (17.9 %) were employed or students at baseline. These numbers are in line with or slightly lower than other Norwegian samples of adult ADHD (Halmoy et al. 2009; Rasmussen and Levander 2009; Gjervan et al. 2012; Lensing et al. 2013). Level of educational achievement was also low, and only 25 patients (21.4 %) had attained senior high school at the age of 28, indicating that almost 80 % could be defined as high school dropouts. These figures differ considerably from the results in a recently published epidemiological study from NordTrøndelag County showing that 17 % of the total youth population was registered as high school dropouts at the
123
age of 24 (De Ridder et al. 2012). This study further showed that the 5-year risk of receiving medical and nonmedical social security benefits was 44 % in the high school dropout group compared with 16 % in the group of high school completers. The authors also found that most of the patients who received medical social security benefits in early adulthood (age 19–23) also received benefits when they were aged 24–28 years, indicating that receiving social security benefits in young adulthood is an important risk factor for persisting working life integration problems. The previous papers from the present sample (N = 117) showed that long duration of CS treatment was predicted positively by the use of extended release formulations of MPH (Torgersen et al. 2012, 2013). Antisocial personality disorder and substance use disorder were related to a shorter duration of CS treatment. Because this was a retrospective, naturalistic study using medical records as source of information it was difficult to collect outcome measures of the effect of treatment on ADHD symptoms and associated emotional symptoms. Good effect on symptoms and quality of life was often described in the records, but not in a systematic and scientifically useful manner. Occupational status was therefore the only outcome measure available at follow-up, except from duration of treatment described in the previous papers (Torgersen et al. 2012, 2013). The aim of the current study was to measure occupational status in adult ADHD patients before and after longterm CS treatment (median length of CS treatment 33 months), using the following categories: employed or student, receiving temporary social security benefits and receiving long-term disability benefits. The study also aimed to identify variables associated with improvement in occupational status during long-term CS treatment.
Methods Setting Study patients were included after admittance to the Department of Psychiatry, Levanger Hospital. This is a local hospital with a catchment area of 90,000 inhabitants living in small towns and rural districts in central Norway. The Department of Psychiatry consists of several inpatient and outpatient units. The patients in the study were assessed and treated at three out-patients units: a unit for general psychiatry, a unit for SUD and a unit for disorders such as autism, Tourette syndrome, ADHD and mental retardation. In the period 1997 to May 2005, it was required that CS treatment of Norwegian ADHD patients older than 18 years had to be approved by a Regional Expert Committee for Hyperkinetic Disorders (RECHD). Under strict
Factors associated with a positive occupational outcome
control by the health authorities, national guidelines were issued and a system to secure adequate diagnosis, treatment and follow-up was initiated. This system for assessment and treatment of adult ADHD is described in earlier papers (Torgersen et al. 2012; Halmoy et al. 2009; Rasmussen and Levander 2009). Subjects The inclusion criteria were as follows: (1) an ADHD diagnosis according to the International Classification of Diseases, 10th revision (ICD-10), Criteria for research (World Health Organization 1992) after an assessment by an experienced psychiatrist at Levanger Hospital; (2) a confirmation of the diagnosis by the RECHD; and (3) commencement of CS treatment as adults. Initially, there were 119 adult patients who consecutively met the inclusion criteria in the study period from 1997 to May 2005. Two patients did not want to participate, which resulted in a final sample of 117 patients, 32 women and 85 men.
treatment, and in many cases also a period after initiation of treatment. Abstinence was in most cases documented by the use of urine tests twice weekly at the office of the general practitioner. In the follow-up period, the patient was seen by the clinician with individual time intervals depending on the patient’s individual needs and wishes. The median number of out-patient consultations the first year after starting CS treatment was 7 (range 0–34). Ethics The Regional Ethical Committee and the Ministry of Health and Care Services have approved the study. The Ministry of Health and Care Services gave permission for only one psychiatrist to read the medical records and collect the data. The patients were informed by postal mail about the study and were given the opportunity not to participate. Procedure for data collection
Clinical assessments at the hospital The national guidelines included systematic assessment of ADHD according to the ICD-10 Criteria for research. Two modifications were made: it was allowed for the inattentive subtype according to Diagnostic and Statistical Manual of Mental Disorders, Fourth edition (DSM-IV) (American Psychiatric Association 1994) to be sufficient for the diagnosis, and it was allowed for the presence of comorbid psychiatric disorders, as long as the diagnostic symptoms of ADHD were present before the appearance of the comorbid disorder. This diagnostic assessment strategy was chosen as a compromise between the fact that ICD-10 is the official diagnostic system used in Norway and the request to have an assessment comparable with the international DSM-IV standards (Halmoy et al. 2009). The requirements of the guidelines included: an evaluation for signs of psychosis, depression, bipolar disorder, anxiety disorders, conduct disorders and SUD; a developmental history confirmed by collateral informants (93.4 % of the cases in the present study: parents 88.4 %, child and adolescence psychiatry (CAP) 30.8 %); a physical examination, blood tests and electrocardiogram; and completion of the two self-report inventories Symptom Checklist 90-items (SCL-90) (Derogatis et al. 1974) and the general adult ADD symptom checklist (GAASC) (Amen 1997). A report with all the information was sent to the RECHD for a definitive conclusion, and the clinicians were not allowed to start CS treatment without a recommendation from the committee. The patients were required to document at least 3 months of abstinence from SUD before initiating CS
The data were collected from the medical records by an experienced psychiatrist (first author). A list of essential variables was made before data collection. Baseline was set to the time the patients started CS treatment as adults. The first patients were included in 1998, and the lasts patients were included in May 2005. The date of follow-up was December 31, 2008, 43 months after inclusion of the last patients. For patients who had terminated treatment before this date, follow-up was set at the date of last contact with the patient documented in the medical records. Outcomes Occupational status at baseline and follow-up was measured using the following categories: (1) employed or student, (2) receiving temporary social security benefits and (3) receiving long-term disability benefits. The first group included patients having their income from ordinary work or students without any kind of social security benefits. The second group had their income from temporary social security benefits, such as social assistance, rehabilitation allowance, sick leave and vocational rehabilitation. The third group, receiving disability benefits, included patients who received a long-term disability pension without any activity or requirement for treatment or rehabilitation. Normally, these patients had received temporary social security benefits for years before being granted a disability benefit. Improvement in occupational status was defined as a change in main income from temporary social security benefits or disability benefits to employment or studies
123
T. Torgersen et al.
from baseline to follow-up (improved group). The group of patients without such improvement is the not improved group. These groups were compared with a number of variables. At baseline self-reported ADHD symptoms (GAASC), self-reported general psychiatric symptoms (SCL-90), criminality, educational level, comorbidity with SUD and personality disorders, and childhood treatment were assessed. A comorbid disorder was diagnosed only if the medical records clearly confirmed the criteria for a DSM-IV diagnosis. The GAASC version used in the present study is a 29-items list of hyperkinetic symptoms with five subscales: attention, impulsivity, restlessness, organization and executive function. The items are measured on a 5-point scale (0–4: never, seldom, sometimes, often and very often). At follow-up, aspects of CS treatment in adulthood were assessed: duration of CS treatment, maintenance dose of CS, duration from first contact with adult psychiatry to diagnosis of ADHD, number of out-patient consultations the first year of CS treatment and the number of patients who changed from one type of CS to another. Information about maintenance dose was collected only for MPH, because this was the main CS drug used by the patients. The CS treatment given is described in detail in a previous paper (Torgersen et al. 2012).
\18 years. The sample was highly comorbid, and there were significant gender differences for antisocial and borderline personality disorders. In the male group, 47.1 % had one or more criminal sentences. These frequencies were significantly lower among females. The most important characteristics, total and by gender, are presented in Table 1. Occupational status at baseline and follow-up At baseline, 77 patients received temporary social security benefits. At follow-up, only 11 patients (14.3 %) in this group had improved their status to employee or student. Thirty-three patients (42.9 %) had a negative development into long-term disability pension, and 33 patients (42.9 %) were still receiving temporary social security benefits. Among the 21 patients who were employed or students at baseline, seven (33.4 %) had a negative development and received a social security benefit at follow-up. At baseline, the group employed or student consisted of 21 patients, 11 employees and 10 students. At follow-up, this group consisted of 25 patients, 20 employees and 5 students. Among the 19 patients who were receiving disability pension at baseline, none improved their occupational status to employee or student at follow-up (Table 2). Improvement in occupational status
Statistics Gender differences in baseline sociodemographic and clinical characteristic and differences between the improved and not improved groups were analyzed by the use of v2 test and Fisher exact test for categorical variables and T test for continuous variables. The data were analyzed by the SPSS (Statistical Package for the Social Sciences, version 17; IBM Corporation, Armonk, NY).
Results Baseline sociodemographic and clinical characteristics The sample consists of 117 patients, predominantly men (72.6 %) with ADHD combined subtype. Mean age when starting CS treatment was 28.6 years (women 30.1, men 28.1). A majority of the patients (60.7 %) had been in contact with Pedagogical and Psychological Services (PPS) in childhood. Half of these (30.8 %) had been treated in CAP, but only 18.8 % had been diagnosed with ADHD at an age \18 years, and 14.5 % had received CS treatment before this age. Level of educational achievement was very low, and only 21.4 % had finished senior high school. There were no significant differences between genders with regard to age, subtype, educational level or CS treatment at an age
123
The 11 patients in the improved group (improved their status from social benefits to work or study) were compared to the not improved group. There was a significant difference in baseline ADHD symptoms as measured by the GAASC, showing higher level of baseline symptoms in the improved group. When analyzing subscales of the GAASC, we found significant differences in impulsivity and organization. The improved group had also a nonsignificant trend toward lower levels of psychiatric symptoms according to SCL-90 Global Severity Index (1.3 vs. 1.6). The improved group had a significantly shorter period from the first contact with adult psychiatry until they got the ADHD diagnosis (11.7 vs. 50.9 months, p \ 0.001). They also had a nonsignificant trend toward longer duration of CS treatment (47.2 vs. 32.4 months) and higher maintenance dose of MPH (65.5 vs. 58.2 mg/day). There were no significant differences between the groups considering baseline age, gender, criminality, educational level or comorbidity. For details, see Table 3.
Discussion In the present study, we found that few patients with adult ADHD improved in occupational status during long-term CS treatment despite adequate doses (Koesters et al. 2009;
Factors associated with a positive occupational outcome Table 1 Baseline sociodemographic and clinical characteristics, total and by gender, in the sample of adult ADHD patients (N = 117)
Gender Age (mean/SD)
Total
%
117
100
28.6
Women
7.6
32 30.1
% 27.4 9.3
Men
%
85
72.6
28.1
p
6.9
0.265c
112
95.7
29
90.6
83
97.6
0.094a
Contact with PPT
71
60.7
18
56.3
53
62.4
0.547b
Treatment in CAP
36
30.8
7
21.9
29
34.1
0.201b
ADHD
22
18.8
3
9.4
19
22.4
0.270a
CD or ODD
13
11.1
3
9.4
10
11.8
0.679a
6
5.1
1
3.1
5
5.9
0.851a
17
14.5
1
3.1
16
18.8
0.052a
Finished junior high school
112
95.7
32
100.0
80
94.1
0.161b
Finished senior high school
25
21.4
3
9.4
22
25.9
0.052b
Employed or student One or more criminal sentence
21 44
17.9 37.6
4 4
12.5 12.5
17 40
20.0 47.1
0.346b 0.001b
Mental retardation
5
4.3
1
3.1
4
4.7
0.706a
Learning disability
15
12.8
5
15.6
10
11.8
0.578a
Asperger syndrome
3
2.6
0
3
3.5
0.282a
Tourette syndrome
5
4.3
2
3
3.5
0.517a
Schizophrenia
2
1.7
0
2
2.4
Alcohol
55
47.0
12
37.5
43
50.6
0.206b
Cannabis
49
41.9
10
31.3
39
45.9
0.153b
Amphetamine
48
41.0
9
28.1
39
45.9
0.082b
Opiates
14
12.0
1
3.1
13
15.3
0.071a
Lifetime major depression
38
32.4
12
37.5
26
30.6
0.477b
Bipolar disorder, type I
4
3.4
2
6.3
2
2.4
0.301a
Bipolar disorder, type II
8
6.8
5
15.6
3
3.5
0.505a
35 13
29.9 11.1
3 9
9.4 28.1
32 4
37.6 4.7
0.003b 0.001b
ADHD combined subtype Childhood diagnoses and treatment
Diagnoses in CAP
Learning disability CS treatment in childhood Functional impairment at baseline
Comorbid disorders at baseline
6.3
Lifetime substance use disorders
CAP child and adolescence psychiatry, PPT pedagogical and psychological service in school, CS central stimulant, CD conduct disorder, ODD oppositional defiant disorder a
Fisher exact test
b
v2 test
c
T test
Antisocial personality disorder Borderline personality disorder
Faraone and Glatt 2010; Torgersen et al. 2008; Wender et al. 2011; Reimherr et al. 2007) and duration of treatment. This does not indicate that the patients did not improve in symptoms or quality of life, but due to the retrospective, naturalistic approach using medical records as the source of information it was difficult to collect additional outcome measures such as ADHD symptoms or associated emotional symptoms at follow-up. Good clinical effect on symptoms was often described in the records, but not in a systematic and scientifically useful manner. Occupational status was the only outcome measure available at follow-up except from duration of treatment described in the previous papers (Torgersen et al. 2012, 2013). Due to the small number of patients in the improved group (11 patients, 9.4 % of the total sample), we assumed limited possibilities to find significant differences between
the improved and not improved group. However, the improved group had significantly higher baseline level of ADHD symptoms compared with the group that did not improve. The improved group also had lower levels of general psychiatric symptoms as measured by SCL-90, but this difference did not reach statistical significance. This may be due to the small numbers. It is possible that the patients with a more ‘‘pure ADHD’’ had better effects of CS treatment on functional outcomes such as occupational status. Buitelaar and colleagues (Buitelaar et al. 2011) argues that greater baseline severity may reflect a more homogeneous and biologically based ADHD subtype, which may respond more strongly to dopamine-enhancing therapy. We also found nonsignificant trends toward longer CS treatment duration and higher maintenance dose of MPH in the improved group. We cannot exclude that the
123
T. Torgersen et al. Table 2 Occupational status at baseline and at follow-up. Median follow-up time was 33 months (N = 117) Baseline
Follow-up
Disability benefits
Disability benefits
18
94.7
N = 19
Temporary social security benefits
1
5.3
19 33
100.0 42.9
Temporary social security benefits
33
42.9
Employed or student
11
14.3
77
100.0
Temporary social security benefits N = 77
Employed or student (no social security benefits) N = 21
Disability benefits
%
Disability benefits
1
4.8
Temporary social security benefits
6
28.6
14 21
66.7 100.0
Employed or student N = 117
N
117
improved group received a more intensive CS treatment for a longer duration than the not improved group resulting in occupational improvement. An alternative explanation is that longer treatment duration and higher MPH dosages may be due to better perceived effect of the treatment and/ or a greater tolerance for stimulants. The finding in the present study is in accordance with recent controlled studies of CS treatment in adult ADHD. A study by Buitelaar and colleagues (Buitelaar et al. 2011) investigated predictors of response in adults with ADHD randomly assigned to osmotic release oral system (OROS)MPH 18, 36 or 72 mg or placebo. The study comprised a 5-week, double-blind period followed by a 7-week, openlabel period. The results showed that a higher baseline level of ADHD symptoms was the strongest predictor of a superior outcome in symptoms as measured by Conners’ Adult ADHD Rating Scale (CAARS). Male gender and lower academic achievement were also predictive for a superior outcome. Another study examined the impact of baseline ADHD symptom severity on lisdexamfetamine dimesylate (LDX) efficacy in a long-term study of adults with ADHD (Ginsberg et al. 2011). Adults from a 4-week, placebocontrolled, forced dose-escalation study with LDX (30–70 mg/day) or placebo were enrolled in a long-term, open-label dose-optimization study for an additional 12 months. Participants were stratified by baseline severity (from the prior short-term study) with Clinical Global Impressions-Severity (CGI-S) scores of 4 (moderately), 5 (markedly) or C6 (severely/extremely ill). Long-term LDX treatment demonstrated increased degree of symptom improvement with greater baseline symptom severity.
123
Table 3 Comparing baseline characteristics for patients that improved and not improved occupational status in the follow-up period (N = 117) Improved N = 11 Women (N, %) 2 18.2 Age at baseline (mean/SD) 28.7 6.9 Baseline self-reported symptoms (mean/SD) SCL-90, global severity Index 1.3 0.8 GAASC total 83.7 7.3 GAASC subscale attention 3.2 0.5 GAASC subscale impulsivity 2.8 0.4 GAASC subscale restlessness 3.2 0.6 GAASC subscale organization 2.9 0.5 GAASC subscale executive 2.8 0.8 function Baseline self-reported criminal activity (N, %) One or more criminal sentences 2 18.2 Two or more types of sentence 1 9.1 Sentence for violence 0 Sentence for theft 0 Sentence for drug-related crime 1 9.1 Sentence for drunk driving 2 18.2 Baseline education (N, %) Finished senior high school 2 18.2 Baseline lifetime comorbid disorders (N, %) Alcohol use disorder 4 36.4 Amphetamine use disorder 5 45.5 Cannabis use disorder 4 36.4 Opioid use disorder 0 Borderline personality disorder 1 9.1 Antisocial personality disorder 2 18.2 Major depression 4 36.4 Treatment in childhood (N, %) Contact with PPT 4 36.4 Diagnosis of ADHD in CAP 2 18.2 Treatment with CS in CAP 2 18.2 Treatment in adulthood (mean/SD) Months in CS treatment 47.2 27.7 MPH maintenance dose in 65.5 15.1 mg/d Months from first contact AP to 11.7 13.7 diagnosis of ADHD Number of out-patient 9.5 8.3 consultations the 1 year Changing type of CS (N, %) 8 72.7
Not improved N = 106
p
30 28.6
28.3 7.7
0.725a 0.972c
1.6 76.2 3.0 2.4 2.7 2.5 2.6
0.8 17.4 0.6 0.7 0.9 0.8 0.8
0.312c 0.024c 0.251c 0.006c 0.125c 0.047c 0.369c
42 25 25 22 12 19
39.6 23.6 23.6 20.8 11.3 17.9
0.205a 0.452a 0.117a 0.122a 1.000a 1.000a
23
21.7
1.000a
51 43 45 14 12 33 34
48.1 40.6 42.5 13.2 11.3 31.1 32.1
0.457b 0.758a 0.759a 0.356a 1.000a 0.502 0.746a
67 20 15
63.2 18.9 14.2
0.108a 1.000a 0.593a
32.4 58.2
27.9 22.6
0.097c 0.300c
50.9
64.3
0.001c
8.4
7.3
0.619c
53
50.0
0.151
SCL-90 symptom checklist 90 items, GAASC general adult ADD symptom checklist, CAP child and adolescence psychiatry, PPT pedagogical and psychological service in school, CS central stimulant, MPH methylphenidate, AP adult psychiatry a Fisher exact test b 2 v test c T test
Factors associated with a positive occupational outcome
Rates of clinical response and symptomatic remission tended to increase with greater baseline severity. The finding that a larger proportion of patients with greater baseline symptom severity have a more ‘‘pure ADHD’’ with better effect of treatment compared with patients with less severe symptoms might explain these findings. Another major finding in the present study was that the improved group had a significantly shorter period from the first contact with adult psychiatry until they got the ADHD diagnosis (11.7 vs. 50.9 months, p = 0.001). The finding that the not improved group had been treated significantly longer in adult psychiatry before getting the ADHD diagnosis probably reflects a more chronic course of mental illness with substantial comorbidity. This negative effect of a more chronic course of mental illness on occupational outcome is recently demonstrated in depressive disorder (Trivedi et al. 2013). The study included out-patients (N = 1928) treated with antidepressants. The important finding was that patients who demonstrated initial treatment resistance were more prone to persistent impairment in occupational productivity than patients experiencing initial response to treatment. Adult ADHD patients with a high level of chronic psychiatric comorbidity and functional impairment may represent a more heterogeneous group of ADHD patients. It is to be expected less effect of stimulant therapy alone due to the substantial part of the variation in functional impairment explained by the comorbid disorders and not ADHD. The finding that few patients improved in occupational status during long-term CS treatment in the present clinical sample may have several causes. The low percentage of employed or students at baseline are in line with or slightly lower than other Norwegian studies on clinical samples of adult ADHD showing employment rates at 22–24 % (Halmoy et al. 2009; Gjervan et al. 2012; Rasmussen and Levander 2009). The rates from Norwegian studies on adult ADHD are surprisingly close to the corresponding rates of 10–20 % in chronic schizophrenia (Tandberg et al. 2012; Marwaha and Johnson 2004), which indicates the severity of the disease in terms of functional impairment. The employment rate in the general adult population in Norway is about 75 % (OECD 2012). The low academic achievement will make it more difficult for the patients to attend work in contemporary Norwegian working life. The high level of criminality measured at baseline can also contribute to problems regarding working life integration and occupational functioning. Further, the patients had predominantly the combined subtype of ADHD, and most studies have showed more symptoms and functional impairment in this subtype than the others (Wilens et al. 2009). In the present clinical sample of adult ADHD patients, the levels of comorbidity with SUD and antisocial
personality disorder were higher than other Norwegian studies (Gjervan et al. 2012; Halmoy et al. 2009; Rasmussen and Levander 2009), European and US (Biederman et al. 1993; Sobanski et al. 2007; Cumyn et al. 2009; Barkley et al. 2008). Level of comorbidity was much higher than most controlled studies of CS treatment in adult ADHD (Torgersen et al. 2008; Peterson et al. 2008). The high level of comorbidity is also a probable cause of the limited improvement in occupational status. Previous studies have shown that ADHD with comorbidities such as depression, anxiety, severe personality disorders and SUD has more negative impact on occupational function than ADHD without comorbidity (Sobanski et al. 2007; Weiss and Hechtman 2006). In an epidemiological study from Nord-Trøndelag County, De Ridder and colleagues (De Ridder et al. 2012) found that 66 % of the persons who had received social security benefits in early adulthood (aged 19–23) also received benefits in a later period (aged 24–28). Data from studies in patients with low back pain have suggested that prolonged duration of disability and sick leave makes return to work more unlikely (Airaksinen et al. 2006). For patients with low back pain, 6 months of sick leave reduces the possibility of returning to work to under 50 %, and after 2 years of sick leave, the probability of returning to work is very low (Waddell and Burton 2005). These results indicate that receiving social security benefits in young adulthood is a phenomenon that persists over time regardless of diagnosis. How the health services and the social security system works, facing the lack of improvement in occupational status for the clients, may play a role in this context. Data suggest that a larger proportion of the population in the Scandinavian countries have their income from social benefits due to illnesses compared with most other Western countries. Thus, treatment, social assistance, rehabilitation allowance and vocational rehabilitation have a potential for improvement. However, Norway is still on top internationally regarding employment-to-population ratio (75 % in 2010), which question the value of data showing high rates of social security dependence (OECD 2012). Another explanation of the association between length of benefit receipt and reduced chance of returning to work might simply be that persons on long-term benefit have more (known and unknown) comorbidity and more social problems (Krokstad et al. 2002). CS treatment itself may have limited effect on occupational function despite the efficacy on ADHD symptoms. Safren and colleagues showed that in CS-treated adult patients work and interpersonal problems appear to be the most important areas of life impairments (Safren et al. 2010). Another study of stability of cognitive deficits in adult ADHD showed that such deficits seem to be
123
T. Torgersen et al.
independent of the course of ADHD and therefore may be a chronic work-related problem (Biederman et al. 2009). The present study has limitations that should be considered. It is a naturalistic study, and the patients are diagnosed and treated by different clinicians with heterogeneous experience and competence. This problem is to some extent compensated for by the fact that all clinicians in the department used the semi-structured national guidelines for assessment of adult ADHD and that the RECHD reconsidered all cases. While most controlled studies of CS treatment exclude patients with comorbidities typical for clinical settings, our study included all patients from a catchment area in a limited time period. Still there are many sources of bias associated with the referral procedure. During the first years of this study, the knowledge about adult ADHD was sparse and variable in the Norwegian health care system, among the patients and in the community, and coincidences could thus decide whether a patient was referred to assessment for ADHD by the general practitioner or not. Patients with serious and ongoing comorbidity, or noncompliance to treatment, might never have reached the point where assessment for ADHD was considered. Overall, referral bias is probably present to a lesser degree in our sample than many other studies of CS treatment of adult ADHD. Retrospective collection of data from medical records gives variable amounts and quality of information from one patient to another. Some information, such as sociodemographic data, information about treatment given, and educational and occupational status, are likely to be reliable. The level of comorbidity may be less reliable and can be used mainly to indicate a high level of comorbidity. As in most studies of pharmacological treatment, we cannot be certain about the patient’s adherence to the prescribed treatment. A major weakness of the study is the lack of secondary outcomes, such as measures of ADHD symptoms, general psychiatric symptoms and quality of life at follow-up. These measures could have made it possible to find correlation between CS treatment, changes in symptoms and occupational status. However, the long duration of CS treatment may indicate that the patients experienced the treatment as helpful and meaningful. The results of the present study indicate that long-term CS treatment itself may have limited effect on occupational status in functionally impaired and highly comorbid samples of adult ADHD. This finding underscores the importance of developing additional and more comprehensive treatment methods for the functional impairments related to adult ADHD. However, the results also indicate that a high baseline ADHD symptom level may be related to a superior outcome not only in short-term ADHD symptom relief,
123
but also in functional outcomes such as occupational status. Further research should explore long-term CS treatment more structured using additional outcome measures such as ADHD symptoms and quality of life.
References Adamou M, Arif M, Asherson P, Aw TC, Bolea B, Coghill D et al (2013) Occupational issues of adults with ADHD. BMC Psychiatry 13:59 Airaksinen O, Brox JI, Cedraschi C, Hildebrandt J, Klaber-Moffett J, Kovacs F et al (2006) Chapter 4. European guidelines for the management of chronic nonspecific low back pain. Eur Spine J 15(Suppl 2):S192–S300 Amen DG (1997) General adult ADD symptom checklist. In: Clark CG (ed) ADHD throughout the lifespan. Random Clark, Las Vegas American Psychiatric Association (1994) Diagnostic and statistical manual of mental disorders (DSM-IV), 4th edn. American Psychiatric Association, Washington Barkley RA, Murphy K, Fischer M (2008) Educational and occupational functioning. In: Barkley RA, Murphy K, Fischer M (eds) ADHD in adults. What science says. The Guilford Press, New York, pp 245–290 Bejerot S, Ryden EM, Arlinde CM (2010) Two-year outcome of treatment with central stimulant medication in adult attentiondeficit/hyperactivity disorder: a prospective study. J Clin Psychiatry 71:1590–1597 Biederman J, Faraone SV, Spencer T, Wilens T, Norman D, Lapey KA et al (1993) Patterns of psychiatric comorbidity, cognition, and psychosocial functioning in adults with attention deficit hyperactivity disorder. Am J Psychiatry 150:1792–1798 Biederman J, Monuteaux MC, Spencer T, Wilens TE, Macpherson HA, Faraone SV (2008) Stimulant therapy and risk for subsequent substance use disorders in male adults with ADHD: a naturalistic controlled 10-year follow-up study. Am J Psychiatry 165:597–603 Biederman J, Petty CR, Ball SW, Fried R, Doyle AE, Cohen D et al (2009) Are cognitive deficits in attention deficit/hyperactivity disorder related to the course of the disorder? A prospective controlled follow-up study of grown up boys with persistent and remitting course. Psychiatry Res 170:177–182 Buitelaar JK, Kooij JJ, Ramos-Quiroga JA, Dejonckheere J, Casas M, van Oene JC et al (2011) Predictors of treatment outcome in adults with ADHD treated with OROS(R) methylphenidate. Prog Neuropsychopharmacol Biol Psychiatry 35:554–560 Cumyn L, French L, Hechtman L (2009) Comorbidity in adults with attention-deficit hyperactivity disorder. Can J Psychiatry 54:673–683 de Graaf R, Kessler RC, Fayyad J, ten HM, Alonso J, Angermeyer M et al (2008) The prevalence and effects of adult attention-deficit/ hyperactivity disorder (ADHD) on the performance of workers: results from the WHO World Mental Health Survey Initiative. Occup Environ Med 65:835–842 De Ridder KA, Pape K, Johnsen R, Westin S, Holmen TL, Bjorngaard JH (2012) School dropout: a major public health challenge: a 10-year prospective study on medical and non-medical social insurance benefits in young adulthood, the Young-HUNT 1 Study (Norway). J Epidemiol Community Health 66:995–1000 Derogatis LR, Lipman RS, Rickels K, Uhlenhuth EH, Covi L (1974) The Hopkins Symptom Checklist (HSCL): a self-report symptom inventory. Behav Sci 19:1–15
Factors associated with a positive occupational outcome Faraone SV, Glatt SJ (2010) A comparison of the efficacy of medications for adult attention-deficit/hyperactivity disorder using meta-analysis of effect sizes. J Clin Psychiatry 71:754–763 Fischer M, Barkley RA, Smallish L, Fletcher K (2002) Young adult follow-up of hyperactive children: self-reported psychiatric disorders, comorbidity, and the role of childhood conduct problems and teen CD. J Abnorm Child Psychol 30:463–475 Fredriksen M, Halmoy A, Faraone SV, Haavik J (2013) Long-term efficacy and safety of treatment with stimulants and atomoxetine in adult ADHD: a review of controlled and naturalistic studies. Eur Neuropsychopharmacol 23(6):508–527 Ginsberg L, Katic A, Adeyi B, Dirks B, Babcock T, Lasser R et al (2011) Long-term treatment outcomes with lisdexamfetamine dimesylate for adults with attention-deficit/hyperactivity disorder stratified by baseline severity. Curr Med Res Opin 27:1097–1107 Gjervan B, Torgersen T, Nordahl HM, Rasmussen K (2012) Functional impairment and occupational outcome in adults with ADHD. J Atten Disord 16:544–552 Goodman DW (2013) Sustained treatment effect in attention-deficit/ hyperactivity disorder: focus on long-term placebo-controlled randomized maintenance withdrawal and open-label studies. Ther Clin Risk Manag 9:121–130 Halmoy A, Fasmer OB, Gillberg C, Haavik J (2009) Occupational outcome in adult ADHD: impact of symptom profile, comorbid psychiatric problems, and treatment: a cross-sectional study of 414 clinically diagnosed adult ADHD patients. J Atten Disord 13:175–187 Hechtman L, Weiss G, Perlman T (1984) Young adult outcome of hyperactive children who received long-term stimulant treatment. J Am Acad Child Psychiatry 23:261–269 Jensen PS, Arnold LE, Swanson JM, Vitiello B, Abikoff HB, Greenhill LL et al (2007) 3-year follow-up of the NIMH MTA study. J Am Acad Child Adolesc Psychiatry 46:989–1002 Koesters M, Becker T, Kilian R, Fegert JM, Weinmann S (2009) Limits of meta-analysis: methylphenidate in the treatment of adult attention-deficit hyperactivity disorder. J Psychopharmacol 23:733–744 Krokstad S, Johnsen R, Westin S (2002) Social determinants of disability pension: a 10-year follow-up of 62,000 people in a Norwegian county population. Int J Epidemiol 31:1183–1191 Kupper T, Haavik J, Drexler H, Ramos-Quiroga JA, Wermelskirchen D, Prutz C et al (2012) The negative impact of attention-deficit/ hyperactivity disorder on occupational health in adults and adolescents. Int Arch Occup Environ Health 85:837–847 Lensing MB, Zeiner P, Sandvik L, Opjordsmoen S (2013) Four-year outcome in psychopharmacologically treated adults with attention-deficit/hyperactivity disorder: a questionnaire survey. J Clin Psychiatry 74:e87–e93 Mannuzza S, Klein RG, Bessler A, Malloy P, LaPadula M (1993) Adult outcome of hyperactive boys. Educational achievement, occupational rank, and psychiatric status. Arch Gen Psychiatry 50:565–576 Marwaha S, Johnson S (2004) Schizophrenia and employment—a review. Soc Psychiatry Psychiatr Epidemiol 39:337–349 Molina BS, Flory K, Hinshaw SP, Greiner AR, Arnold LE, Swanson JM et al (2007) Delinquent behavior and emerging substance use in the MTA at 36 months: prevalence, course, and treatment effects. J Am Acad Child Adolesc Psychiatry 46:1028–1040 Murphy K, Barkley RA (1996) Attention deficit hyperactivity disorder adults: comorbidities and adaptive impairments. Compr Psychiatry 37:393–401 OECD (2012) Employment rate % of working age population. OECDiLibrary July 11. doi:10.1787/20752342-table4 Peterson K, McDonagh MS, Fu R (2008) Comparative benefits and harms of competing medications for adults with attention-deficit
hyperactivity disorder: a systematic review and indirect comparison meta-analysis. Psychopharmacology 197:1–11 Rasmussen K, Levander S (2009) Untreated ADHD in adults: are there sex differences in symptoms, comorbidity, and impairment? J Atten Disord 12:353–360 Reimherr FW, Williams ED, Strong RE, Mestas R, Soni P, Marchant BK (2007) A double-blind, placebo-controlled, crossover study of osmotic release oral system methylphenidate in adults with ADHD with assessment of oppositional and emotional dimensions of the disorder. J Clin Psychiatry 68:93–101 Safren SA, Sprich SE, Cooper-Vince C, Knouse LE, Lerner JA (2010) Life impairments in adults with medication-treated ADHD. J Atten Disord 13:524–531 Satterfield JH, Faller KJ, Crinella FM, Schell AM, Swanson JM, Homer LD (2007) A 30-year prospective follow-up study of hyperactive boys with conduct problems: adult criminality. J Am Acad Child Adolesc Psychiatry 46:601–610 Shaw M, Hodgkins P, Caci H, Young S, Kahle J, Woods AG et al (2012) A systematic review and analysis of long-term outcomes in attention deficit hyperactivity disorder: effects of treatment and non-treatment. BMC Med 10:99 Sobanski E, Bruggemann D, Alm B, Kern S, Deschner M, Schubert T et al (2007) Psychiatric comorbidity and functional impairment in a clinically referred sample of adults with attention-deficit/ hyperactivity disorder (ADHD). Eur Arch Psychiatry Clin Neurosci 257:371–377 Tandberg M, Ueland T, Andreassen OA, Sundet K, Melle I (2012) Factors associated with occupational and academic status in patients with first-episode psychosis with a particular focus on neurocognition. Soc Psychiatry Psychiatr Epidemiol 47: 1763–1773 Torgersen T, Gjervan B, Rasmussen K (2008) Treatment of adult ADHD: is current knowledge useful to clinicians? Neuropsychiatr Dis Treat 4:177–186 Torgersen T, Gjervan B, Nordahl HM, Rasmussen K (2012) Predictive factors for more than 3 years’ duration of central stimulant treatment in adult attention-deficit/hyperactivity disorder: a retrospective, naturalistic study. J Clin Psychopharmacol 32:645–652 Torgersen T, Gjervan B, Rasmussen K, Vaaler A, Nordahl HM (2013) Prevalence of comorbid substance use disorder during long-term central stimulant treatment in adult ADHD. Atten Defic Hyperact Disord 5:59–67 Trivedi MH, Morris DW, Wisniewski SR, Lesser I, Nierenberg AA, Daly E et al (2013) Increase in work productivity of depressed individuals with improvement in depressive symptom severity. Am J Psychiatry 170:633–641 Waddell G, Burton AK (2005) Concepts of rehabilitation for the management of low back pain. Best Pract Res Clin Rheumatol 19:655–670 Weiss G (1985) Hyperactivity. Overview and new directions. Psychiatr Clin N Am 8:737–753 Weiss M, Hechtman L (2006) A randomized double-blind trial of paroxetine and/or dextroamphetamine and problem-focused therapy for attention-deficit/hyperactivity disorder in adults. J Clin Psychiatry 67:611–619 Wender PH, Reimherr FW, Marchant BK, Sanford ME, Czajkowski LA, Tomb DA (2011) A one year trial of methylphenidate in the treatment of ADHD. J Atten Disord 15:36–45 Wigal T, Brams M, Gasior M, Gao J, Squires L, Giblin J (2010) Randomized, double-blind, placebo-controlled, crossover study of the efficacy and safety of lisdexamfetamine dimesylate in adults with attention-deficit/hyperactivity disorder: novel findings using a simulated adult workplace environment design. Behav Brain Funct 6:34
123
T. Torgersen et al. Wilens TE (2003) Does the medicating ADHD increase or decrease the risk for later substance abuse? Rev Br Psiquiatr 25:127–128 Wilens TE, Biederman J, Faraone SV, Martelon M, Westerberg D, Spencer TJ (2009) Presenting ADHD symptoms, subtypes, and
123
comorbid disorders in clinically referred adults with ADHD. J Clin Psychiatry 70:1557–1562 World Health Organization (1992) International classification of diseases, 10th revision. Criteria for research, Geneva
