Journal of Affective Disorders 175 (2015) 351–358
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Long-lasting effects of affective disorders and childhood trauma on dispositional optimism Rosalie Broekhof a, Nathaly Rius-Ottenheim a,n, Philip Spinhoven a,b, Roos C. van der Mast a, Brenda W.J.H. Penninx a,c,d, Frans G. Zitman a, Erik J. Giltay a,n a
Department of Psychiatry, Leiden University Medical Center, Leiden, The Netherlands Institute of Psychology, Leiden University, Leiden, The Netherlands c Department of Psychiatry, University Medical Center Groningen, Groningen, The Netherlands d Department of Psychiatry and EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands b
art ic l e i nf o
a b s t r a c t
Article history: Received 25 July 2014 Received in revised form 13 January 2015 Accepted 14 January 2015 Available online 23 January 2015
Background: Dispositional optimism, a personality trait characterized by generalized positive expectations towards the future, is thought to remain rather stable over time. It is however largely unknown to what extent affective disorders and its risk factors affect dispositional optimism. Methods: We examined the association between (lifetime) affective disorders and childhood trauma with dispositional optimism in a sample of 2104 subjects (aged 18–65 years) from the Netherlands Study of Depression and Anxiety (NESDA). Dispositional optimism was measured with the Life Orientation Test Revised (LOT-R). Diagnoses of depressive and anxiety disorders were based on the Composite Interview diagnostic Instrument (CIDI).Childhood trauma was assessed using the Childhood Trauma Interview (CTI) and life-events with the List of Threatening Events Questionnaire (LTQ). Results: The 2104 participants were on average 46.0 (SD 13.1) years old and 65.8% were female. Multivariate analyses showed that dispositional optimism was inversely associated with current affective disorders (depression: B¼ 1.089 and anxiety: B¼ 1.066, both po0.001), but also with remitted affective disorders (depression: B¼ 0.822 and anxiety: B¼ 0.558, both po0.001) and severity of depression (B¼ 4.230; po0.001). A history of childhood emotional maltreatment (B¼ 0.905, po0.001) was related to lower optimism, whilst positive life-events were associated with higher levels of optimism (B¼ 0.235, p40.001). Limitations: The cross-sectional design hampers inferences about causality. Conclusion: Lower levels of dispositional optimism are associated with stage of affective disorders, even after remission, and a history of childhood emotional maltreatment. Identification of the risk factors contributes to understand fluctuations in dispositional optimism. & 2015 Elsevier B.V. All rights reserved.
Keywords: Dispositional optimism Childhood trauma Depression Anxiety Remitted
1. Introduction Dispositional optimism is a personality trait that refers to the extent to which individuals hold positive expectations for their future (Carver et al., 2010; Carver and Scheier, 2014). As such, it is associated with a successful adaptation in the face of stress or adversity and better health outcomes (Rasmussen et al., 2009). Although this personality trait is thought to show little variation over time (Schou et al., 2005), several factors may account for fluctuations in optimism. In addition to genetic liability (Plomin et al., 1992), increasing evidence suggests that certain environmental
n Correspondence to: Leiden University Medical Center, Department of Psychiatry, P.O. Box 9600, 2300RC, Leiden, The Netherlands. Tel.: þ31 71 5263448; fax: þ31 71 5248156. E-mail address: [email protected] (E.J. Giltay).
http://dx.doi.org/10.1016/j.jad.2015.01.022 0165-0327/& 2015 Elsevier B.V. All rights reserved.
factors may affect one's disposition to optimism (Mosing et al., 2009). Potential environmental factors include social resources, lifestyle factors and (mental) health parameters. Identification of these factors may contribute to our understanding of how optimism develops and fluctuates over time. In this study we focused on the effects of affective disorders and childhood trauma on levels of optimism. Numerous studies have found inverse associations between presence of depressive and anxiety disorders and dispositional optimism, both in cross-sectional (Colby and Shifren, 2013; Vahia et al., 2010) and longitudinal designs (Giltay et al., 2006; Vickers and Vogeltanz, 2000). One recent study hypothesized that this association might be mediated by an absence of positive cognitive bias in depressed individuals (Korn et al., 2014). In this study, participants were asked to predict the probability of experiencing adverse life events in the future. Depressed individuals showed less positive expectations than healthy controls. Furthermore, this study showed that the decreased
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positive cognitive bias was dependent on the severity of the depressive symptoms. Surprisingly, little is known about the potential lasting effects of remitted affective disorders on one's levels of dispositional optimism. Depression causes durable imbalances in motivational systems (Vergara and Roberts, 2011) and may therefore affect optimism. Interestingly, persons with remitted depression have an altered responsiveness to emotional stimuli, particularly to negative ones (Anderson et al., 2011; Merens et al., 2008). A study among 230 participants with different stages of affective disorders (remitted, current, no history) showed that participants in a remitted stage of depression displayed an attention bias for negative cues in comparison to participants with a current depression state (Anderson et al., 2011). In other words, having a history of depression seems to affect emotional processing. Consistent with these findings, previous studies among participants with a history of depression found an abnormal activity of different brain areas (the amygdala and the anterior cingulate cortex) that are involved in the imaging of (positive) future events (Morina et al., 2011). Accordingly, a previous study of our group showed that dispositional optimism was positively correlated with a higher ability to picture vividly future positive events in the mind's eye (Blackwell et al., 2013). It is therefore possible that lifetime affective disorders affect one's levels of optimism by decreasing the ability to generate mental images of future positive events. Childhood trauma has also been associated with lower levels of optimism and higher risk of affective disorders (Kessler et al., 2010). In a study among almost 20,000 Finnish workers, childhood adversities were associated with lower levels of optimism, showing a dose–response relationship (Korkeila et al., 2004). Similarly, other studies among healthy participants have found that childhood adversities were related to a lower resilience, an overarching construct including optimism, and to lower psychological wellbeing in adulthood (Herrenkohl et al., 2012; Simeon et al., 2007). A possible explanation is that adverse childhood experiences and the inability of the caregiver to provide comfort in times of need may alter cognitive assumptions and the ability to visualize positive representations of the future. In this study, we aimed to examine the association between dispositional optimism, stage of affective disorders and childhood trauma in a cohort from the NESDA-study comparing levels of optimism across groups with current, remitted and no affective disorders. We explored whether remitted (or lifetime) affective disorders affected levels of optimism and whether this association was dependent on the severity of affective disorders. We also examined the association between dispositional optimism and childhood trauma. Based on earlier results in the NESDA-cohort, we expected a stronger association of certain subtypes of childhood trauma (i.e. childhood emotional neglect) with low optimism. We hypothesized that lifetime affective disorders or childhood trauma would be associated with lower levels of dispositional optimism.
2. Material and methods 2.1. Participants Participants were recruited as part of NESDA, an ongoing longitudinal study designed to examine the long term course of depressive and anxiety disorders. The design and population characteristics have been described in detail elsewhere (Penninx et al., 2008). Briefly, NESDA included 2981 participants recruited from the community, primary care practices and specialized mental health care centers, aged between 18 and 65 years. The assessments consisted of face-toface interviews, written questionnaires, and biological measurements. For the current study, data from the 4-year follow-up wave were used as the dispositional optimism scale was introduced in
this wave. Of the initial 2981 participants, 877 (29.4%) were excluded because of being lost-to-follow-up, refusal, or missing data. The reasons for lost-to-follow-up were: 18 (0.6%) persons had died, 10.6% refused to participate, 2.2% could not be contacted, and 1.7% were unable to participate because of health reasons (Lamers et al., 2012). A total of 140 (4.7%) participants had expressed a “hard refusal” and were not contacted for a further wave. Next, 298 (10.0%) had missing items on the Life Orientation Test Revised (LOT-R) and important covariates. Thus, a total of 2104 participants had complete data on the LOT-R score and the main independent variables. The cohort of 2104 participants (age range 18–65 years) included 643 (30.6%) patients with current affective disorders, 1027 (48.8%) with lifetime affective disorders, and 434 (20.6%) controls without lifetime affective disorders. The 877 excluded participants versus 2104 included participants were similar for gender (p¼0.32) and age (p¼0.45), but had a lower level of education (11.3 [SE 0.1] versus 12.5 [SE 0.1] po0.001) and were more likely to have a current major depressive disorder (47% versus 33.4%; po0.001) at the baseline assessment. The study protocol was approved by the Ethical Review Board of each participating center and all participants signed an informed consent. 2.2. Measurements 2.2.1. Indicators of affective disorders In the NESDA study, diagnoses of depressive and anxiety disorders according to DSM-IV criteria were assessed by trained clinical staff using the CIDI lifetime version 2.1. Severity of depressive symptoms was assessed by the Inventory for Depressive Symptomatology (IDS) questionnaire. According to the IDS total score, severity of depressive symptoms was subsequently categorized into four groups: normal (o14 points), mild (14–26 points), moderate (27– 39 points), and severe (439 points) (Rush et al., 1996). For the present study, we categorized stage of affective disorders as follows: current (in the last 6 months) and remitted (lifetime non-current) diagnoses of depressive disorders (major depressive disorder and dysthymia) and anxiety disorders (panic disorder, agoraphobia, social phobia, or generalized anxiety disorder). The remitted diagnoses were identified using the combined CIDI diagnoses data from the baseline and 2 and 4 years follow-up waves. 2.2.2. Childhood trauma and life events Childhood trauma was assessed retrospectively using the Childhood Trauma Interview that has previously been used in the Netherlands Mental health Survey and Incidence Study (NEMESIS) (de Graaf et al., 2004). Participants were asked whether they had experienced any kind of emotional or psychological neglect, physical or sexual abuse before the age of 16. The definition of emotional neglect included lack of parental attention or support and ignorance of one's problems and experiences. Psychological abuse was defined as being verbally abused, undeserved punishment, subordinated to siblings, and being blackmailed. Physical abuse was defined as being kicked or hit with hands or another object, beaten up or physical abuse in any other way. Because psychological abuse and emotional neglect often occur concomitantly, we collapsed these two variables into a new variable named emotional maltreatment. Sexual abuse was defined as being sexually approached against one's will, meaning being touched or having to touch someone in a sexual way. To assess the occurrence of negative life events since the last wave, the List of Threatening Events Questionnaire (LTE-Q; Brugha and Conroy, 1985; Brugha and Cragg, 1990) was administered (e.g., ‘Serious financial troubles’, ‘Death of a first-degree relative’). The LTE-Q was extended by seven items referring to positive life events: (1) an immediate family member recovered from a serious illness; (2) met a
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Table 1 Sociodemographic and lifestyle characteristics of 2104 participants according to affective disorders status.
Age (years) Male gender Education (years) Socioeconomic resources: Married Living together with partner No. of persons in household Unemployment Income (a € 1000 netto/ month) Physical activity: Low Moderate High Smoking: Never Former Current Alcohol use: Non-drinker 1–14 glasses/wk Z 15 glasses/wk Chronic diseaseb Antidepressant use Benzodiazepine use
No lifetime affective disorders (n ¼434)
Lifetime ( 46 m) affective disorders (n¼ 1027)
Current ( r 6 m) affective disordersa (n¼ 643)
P-value
45.6 714.7 41.0% 13.0 7 3.2
45.9 7 12.9 33.1% 12.5 7 3.1
46.3 7 12.5 31.3% 12.2 7 3.3
0.70 0.002 o 0.001
48.2% 68.2%
44.5% 63.2%
40.3% 57.1%
0.009 o 0.001
2.3 71.2 29.3% 3.7 72.7
2.3 7 1.3 34.3% 2.9 7 2.0
2.2 7 1.1 45.9% 2.6 7 1.9
0.054 o 0.001 o 0.001
19.1% 43.1% 37.8%
18.9% 43.4% 37.7%
25.0% 44.9% 30.0%
0.001
39.6% 39.4% 21.0%
28.2% 40.3% 31.5%
30.5% 35.5% 34.1%
o 0.001
11.5% 86.4% 2.1% 14.7% 0.9% 1.4%
16.0% 80.9% 3.1% 18.9% 20.3% 7.7%
20.4% 73.1% 6.5% 23.2% 31.6% 21.9%
0.12
0.001 o 0.001 o 0.001
Data are percentages or mean 7 standard deviation (SD). P-values for linear trend over the three categories. a b
Current affective disorders was defined as a 6-month (6 m) anxiety or depressive disorder. Chronic disease comprised diabetes mellitus, stroke or other cardiovascular diseases, cancer, and rheumatoid arthritis.
new partner; (3) became friends; (4) have been on holiday; (5) new job or an important promotion; (6) an education completed; and (7) be better off financially. Moreover, participants could indicate the incidence of positive and negative life events not covered by the 19 standard items of the interview. 529 Of the 1209 participants indicated 1191 life events in addition to events covered by the standard 19 life events (79.6% 1; 17.0% 2; 2.6% 3; and 0.8% 4 additional events). These extra events were scored by two independent raters (two master students psychology) as belonging to one of the standard 19 life event categories (n¼522) or as presenting a different type of positive (n¼ 301; e.g., marriage, birth of a child), negative life events (n¼ 305; e.g., divorce of child, dead of a pet) or non-classifiable event (n¼ 63). Only in 36 (3.0%) of the ratings the two raters disagreed and had to reach consensus. In the total sample the direction of the correlations of individual positive and negative life events with 1-month recency diagnosis of depressive and/or anxiety disorder was in accordance with the a priori normatively defined valence of the life event items with negative life events showing a positive correlation and positive life events a negative correlation with depressive and anxiety diagnoses. Consequently, negative and positive life events during the 2year follow-up period (both the standard events on the LTE-Q as well as the additionally reported events) were summed in order to derive two separate measures, one for the total number of negative (range 0–16) and one for the total number of positive life events (range 0–11). The two subscales proved to be totally unrelated, r ¼0.04, ns. In addition, positive as well as negative life events were dated in months starting from baseline and used as time-dependent covariates.
2.2.3. Dispositional optimism Dispositional optimism was assessed using the LOT-R that consists of 10 items rated on a five-point Likert scale, with 6 items
yielding an optimism score and 4 filler items not used in scoring (Glaesmer et al., 2012). Participants were asked to indicate the extent of their agreement with each of the items on a 0–4 point scale. Three negatively coded items needed to be reversed coded. The total LOT-R score ranges from 0 to 24 points, with higher scores being indicative of a higher level of optimism. For the computation of optimism scores one missing item per subject was allowed. In this study the Cronbach's alpha was 0.87. Dispositional optimism was used in this study as a continuous variable. 2.2.4. Covariates Sociodemographic and lifestyle characteristics were obtained through standardized questionnaires. This information included age, gender, and years of education. Smoking status was classified as no smoking, former smoking, and current smoking. Physical activity was assessed using the International Physical Activity Questionnaire (Booth, 2000) and categorized into low, moderate and high. Alcohol use was categorized as non-drinker, moderate drinker (1–14 glasses a week), and heavy drinker ( 415 glasses a week). The prevalent diagnoses of cardiovascular disease, cancer, stroke and diabetes mellitus were assessed by standardized questionnaires, and number of chronic diseases was calculated. 2.3. Statistical analyses A one-way analysis of variance was conducted to explore the association between stages of affective disorders, defined as no lifetime affective disorders, lifetime affective disorders and current affective disorders, and sociodemographic and lifestyle characteristics. Descriptive data are presented as numbers and percentages for categorical variables and means with standard deviations for normally distributed, continuous variables (Table 1). Linear regression analyses were used to examine the association between dispositional optimism and sociodemographic
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and lifestyle characteristics in persons without affective disorders to yield the potential confounders in this population. The association was also explored in an adjusted model, including the following covariates: gender, age, years of education, and physical activity (Table 2). Also multivariate linear regression analyses were used to assess the association of optimism with presence and severity of affective disorders (using the IDS-SR) in the whole sample. An additional linear regression analysis was conducted to explore the association between each of the subtypes of childhood trauma, life events and dispositional optimism. To explore the independent effect of each type of maltreatment, we used a forced entry in which we introduced all three subtypes as predictors of the model. Both analyses were repeated in adjusted models in which the abovementioned covariates were taken into account. To test for multicollinearity, the Variance Inflation Factor (VIF) score was examined for each variable in each model. We used the arbitrary rule of thumb cut-off criterion of 2 for deciding when a given independent variable displayed multicollinearity. As the variable emotional neglect and psychological abuse approached this cut off (i.e., VIF of 1.958), we decided to collapse them into one emotional maltreatment variable as has previously been done (van Harmelen et al., 2010). Finally, we examined the interactions between childhood maltreatment and affective disorders by adding the appropriate interaction terms to the multivariable model. However, we found no evidence of significant interaction terms (both p's 4 0.20). All p-Values are two tailed and considered statistically significant at the level of p o0.05. Data analyses were performed using SPSS version 20.0 (Chicago, IL) for Windows.
3. Results Table 1 shows the sociodemographic and lifestyle characteristics according to the stage of affective disorders. The 2104 participants were on average 46.0 (SD 13.1) years old and 65.8% were female. Of the 2104 participants, 643 (30.6%) met criteria of current affective disorders, 1027 (48.8%) for lifetime affective disorders, and 434 (20.6%) had no lifetime affective disorders. The participants without current affective disorders had received more years of education. The socio-economic profile was less favorable in the group with current affective disorders, as these participants were less likely to be married, were more likely to be unemployed, and had a lower income than the participants without current affective disorders. Current affective disorders were also associated with unhealthy lifestyle behaviors as participants from this group were more likely to be current smokers and had a lower level of physical activity. As expected, current affective disorders was also associated with a higher prevalence of chronic physical illnesses and with the use of antidepressants and benzodiazepines. Table 2 reports the associations between sociodemographic and lifestyle characteristics and dispositional optimism in participants without current affective disorders. Higher levels of optimism were independently associated with more years of education, more physical activity, and having less frequently a history of affective disorders (i.e., anxiety and depressive disorder), which were included in the subsequent multivariable models. We additionally repeated these analyses on the healthy subpopulation, finding that higher physical activity and a higher level of education were the significant independent correlates of dispositional optimism. We also examined the distribution of dispositional optimism in our sample (data not shown). When we considered the outermost 5% of observations to define limits for one-sided reference
Table 2 Associations with optimism in 1461 participants without current affective disordersa. Unadjusted
Age (per year) Male gender Education (years) Socioeconomic resources: Married Living together with partner No. of persons in household Not working Income (per € 1000/month) Physical activity: Low Moderate High Smoking status: Never Former Current Alcohol use: Non-drinker 1–14 glasses/wk Z15 glasses/wk Chronic diseaseb Remitted affective disorders Antidepressant use Benzodiazepine use
Adjusted
B 7 SE
P-value
B 7SE
P-value
0.0107 0.006 0.082 7 0.171 0.164 70.025
0.11 0.63 o 0.001
0.004 70.007 0.166 7 0.167 0.129 70.027
0.57 0.32 o 0.001
0.253 7 0.164 0.5337 0.170 0.1447 0.066 0.4647 0.174 0.206 70.036
0.12 0.002 0.03 0.008 o 0.001
0.036 7 0.232 0.3167 0.240 0.036 7 0.078 0.0457 0.184 0.077 70.041
0.88 0.19 0.65 0.81 0.06
Ref. 0.0117 0.165 0.390 7 0.168
0.95 0.02
Ref. 0.284 7 0.218 0.628 7 0.221
0.190 0.005
Ref. 0.340 7 0.167 0.649 70.181
0.04 o 0.001
Ref. 0.191 70.192 0.187 70.208
0.32 0.37
Ref. 0.438 7 0.215 0.584 7 0.495 0.4827 0.214 1.906 70172 1.1167 0.230 1.1117 0.348
0.04 0.24 0.02 o 0.001 o 0.001 0.001
0.066 7 0.230 0.0747 0.519 0.164 7 0.218 1.658 7 0.180 0.393 7 0.231 0.3797 0.342
0.77 0.89 0.45 o 0.001 0.09 0.27
Data are presented as beta coefficients and standard errors. Adjusted: all the variables are included in the adjusted model. a b
Current affective disorders was defined as a 6-month (6 m) anxiety or depressive disorder. Chronic disease comprised diabetes mellitus, stroke or other cardiovascular diseases, cancer, and rheumatoid arthritis.
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355
Cumulative prevalence (%)
100 LOT-R score: 16>–24 (highest optimism) 12>–16 8>–12 4>–8 0–4 (lowest optimism)
80
60
40
20
Co ntr ol g (n= roup 43 4) Re mi tte d (n= grou 10 p 27 An ) xie ty dis or de r (n= only De 25 pre 4) ss ive dis ord er (n= only 18 2) Co mo rb id g (n= roup 20 7)
0
Cumulative prevalence (%)
100 LOT-R score: 16>–24 (highest optimism) 12>–16 8>–12 4>–8 0–4 (lowest optimism)
80
60
40
20
mo n (n= ths 83 ) 6-1 2
12 -24 mo n (n= ths 73 )
-72 mo (n= nths 35 8) 24
>7
2m o (n= nths 53 1)
0
Time past since last episode Fig. 1. Cumulative prevalence of optimism scores depending on the presence of affective disorders.
intervals (95th percentiles; P95), we found a cut off value of 11 in the group without a history of affective disorders. Fig. 1 shows the cumulative prevalence of optimism scores depending on the presence of affective disorders. Participants with no lifetime affective disorders (i.e. control group) were overall the most optimistic group of subjects, also when compared to subjects with remitted affective disorders. Participants with either an anxiety or a depressive disorder were overall less optimistic, with those with a depressive disorder scoring slightly lower on optimism. Participants with a comorbid anxiety and depressive disorder showed the poorest levels of optimism. In a subanalysis within the remitted group, we found that participants who had suffered a depressive episode within the time span of only 6 to 12 months before measurement had the lowest optimism levels, which gradually improved as the time elapsed since the last depressive episode was longer (P o0.001 by chi-squared test).
Multivariate linear regression analyses were conducted to examine the associations between anxiety and depression disorders and dispositional optimism, depending on severity and stage of affective disorders (Fig. 2). The severity of depressive symptoms (i.e. IDS-SR total score) was inversely associated with levels of dispositional optimism, even after adjustment for confounders (B¼ 4.230; po0.001). Furthermore, persons who met criteria of affective disorders displayed lower optimism scores in comparison to persons who were free of current affective disorders (depression: B¼ 1.089 and anxiety: B¼ 1.066, both p'so0.001). This association was not only present in persons with current affective disorders, but also in persons with lifetime affective disorders (depression: B¼ 0.822 and anxiety: B¼ 0.558, both p'so0.001). Table 3 shows the results of the linear regression analyses on the associations between childhood trauma subtypes and life-events with dispositional optimism. In the unadjusted models, optimism
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Fig. 2. Effects of affective disorders on dispositional optimism in 2104 participants. Data are presented as B-coefficients and standard errors (SE), and in forest plots as mean B-coefficients with error bars indicating the 95% confidence, intervals. The severity of depressive symptoms was categorized according to IDS-SR scores (normal o 14 points, mild 14–26 points, moderate 27–39 points, and severe 439 points). Mean values, standard errors (SE), and P-values are obtained by linear regression analyses, adjusted for gender, age, years of, education, and physical activity, as well as all other variables in this table. Table 3 Effects of childhood trauma and recent life events on dispositional optimism in 2104 subjects. Unadjusted
Emotional maltreatment Physical abuse Sexual abuse No. negative life events since 2 yr No. positive life events since 2 yr
Adjusted
B 7SE
P-value
B7 SE
P-value
–2.4747 0.230 1.6437 0.290 0.698 7 0.239 0.298 7 0.056 0.3517 0.056
o0.001 o0.001 0.004 o0.001 o0.001
0.9057 0.249 0.4017 0.295 0.098 7 0.213 0.048 7 0.051 0.2357 0.055
o 0.001 0.18 0.64 0.34 o 0.001
Data are presented as B-coefficients and standard errors (SE). Childhood trauma variables are scores that range from 0 (i.e., no) to 0.5 (i.e., once or sometimes) to 1.0 (regularly, often or very often). Emotional maltreatment was calculated as the mean of emotional neglect and psychological abuse (because of the strong association between both forms of childhood maltreatment). P-values are obtained by linear regression analyses, adjusted for gender, age, years of education, physical activity, severity of depressive symptoms, depressive disorders (i.e., never/remitted/current), anxiety disorders (i.e., never/remitted/current), and each of the other two forms of childhood trauma.
was inversely associated with all subtypes of childhood trauma. However, these associations were substantially weakened after adjusting for important sociodemographic, clinical and lifestyle characteristics and other childhood trauma subtypes. Only emotional maltreatment showed an independent association with optimism scores over and above the effect of possible confounders and other abuse types (B-coefficient¼ 0.905; SE 0.249; po0.001). We found that positive life events were predictive of higher optimism scores (B-coefficient¼0.235; SE 0.055; po0.001), but that negative life events were not.
4. Discussion The present study shows an association between low optimism and presence of affective disorders. Interestingly, a history of affective disorders was associated with lower levels of optimism, even after achieving remission. There was a dose–response relationship between the severity of depressive symptoms, time elapsed since the last episode, and levels of optimism. In other words, a more severe and a more recent depressive episode were associated with lower levels of optimism. Furthermore, an association was found between lower levels of optimism and childhood trauma, particularly with childhood emotional maltreatment. Our finding of an inverse association between depressive symptoms and dispositional optimism is in line with some earlier results (Giltay et al., 2006). Our study elaborates on the results of Korn et al. replicating their finding of an inverse association between dispositional optimism and depressive symptoms (Korn et al., 2014). As in their study, we also found that more severely depressed persons displayed lower levels of optimism. In our study we went one step further by exploring the association in a larger sample and including stage of affective disorders. In this regard, we found that not only current affective disorders, but also remitted affective disorders were
associated with lower levels of optimism. It is possible that remitted patients may realize that they are at increased risk for future relapse and may therefore rationally hold less optimistic beliefs. Maladaptive cognitive bias may be the clue to interpret these associations. It is possible that a depressive episode alters the appraisal of negative and positive cues, leading to a different interpretation of events and changing individual's expectations towards the future. This mechanism may explain why formerly depressed are more prone to new depressive episodes as they have fewer buffers. Depression may erode optimistic cognitive styles and reduce coping abilities. Once crystallized, negative representations may be more difficult to alter than positive representations (Joiner, 2000). As a result, the levels of dispositional optimism may decrease after an episode of a depressive or anxiety disorder. This association has also a biological substrate since neuroimaging studies have found microstructural changes and an abnormal connectivity in the amygdala among persons with a major depression, even after achieving remission (Arnold et al., 2012). These are the same brain regions that show enhanced activity in individuals with higher levels of optimism (Sharot et al., 2007). The amygdala is involved in recalling past (threatening) events that are reconstructed to form representations of possible future scenarios (Addis et al., 2007). In accordance with these results, one could hypothesize that a depressive episode may change neuronal networks that are involved in the projection and appraisal of future positive events. However, our results also suggest that changes in cognitive appraisals may dissipate over time. We found that levels of optimism were higher the longer the time elapsed since the last depressive episode. In our study, childhood emotional maltreatment was also associated with lower levels of optimism, even after adjustment for confounders. It has previously been found that caregiver's emotional coldness and the inability to empathize may lead to long-lasting psychological adverse effects, such as emotional and cognitive disturbances (Norman et al., 2012). Only when the
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traumatic event is overcome successfully, it does result in posttraumatic growth and strengthens optimism (Bostock et al., 2009). Otherwise, failure to overcome the traumatic event results in disengagement and a lower perception of self-mastery and, possibly, lower levels of optimism. Earlier studies based on the NESDA cohort have shown that childhood emotional abuse is associated with negative cognitive styles. In line with our findings, these studies described a stronger association for childhood emotional maltreatment than for childhood sexual or physical abuse (van Harmelen et al., 2010). In their discussion, the authors argued that childhood emotional maltreatment may be more strongly associated with negative cognitions since in this subtype of abuse negative self-associations are explicitly handed to the child. Trauma-induced generalized negative cognitive schemas may alter the emotional self-regulation that underlies optimistic outcome expectancies. It is thought that these psychological outcomes are the result of alterations in neurobiological development. Again, neuroimaging studies have found higher amygdala responsiveness to negative cues in individuals with a history of childhood maltreatment (Dannlowski et al., 2013). Abused individuals seem to be caught in a negative loop, where emotional abuse leads to a negative cognitive bias, which results in a negative representation of future events. We found that sporadic but not more frequent psychological and physical abuse was associated with lower optimism. This may be due to the fact that we also adjusted for the severity of depressive symptoms, which may have somewhat over-adjusted the effects of low mood states, as these may be a consequence of trauma-induced low optimism. There are some limitations to the study at hand that should be discussed. First, the cross-sectional design of our study limits causal inference of the directional routes of these associations. Next, it could be argued that the association between low dispositional optimism and childhood emotional maltreatment might have arisen from a recall bias due to the retrospective report of childhood trauma. Yet, childhood trauma was measured at the baseline assessment, four years before the assessment of dispositional optimism and current affective disorders, which may have reduced recall bias and reverse causation. Also, the incidence of life events was reported retrospectively and we did not verify these events or whether other life events were missing. Another limitation is that we could not test whether the associations were mediated or moderated by other psychological dimensions like self-esteem. The main strength of this study lies in its large sample size, the use of validated diagnoses based on structured diagnostic interviews (i.e., CIDI) to determine (history of) affective disorders and the use of a semi-structured interview to assess different types of childhood abuse. Dispositional optimism was measured with the Life Orientation Test Revised, a validated and internally consistent instrument. Our study design enabled us to analyze associations by taking into account the effect of current and remitted diagnoses of depressive or anxiety disorders, childhood trauma and the severity of these symptoms. Our results may provide a basis for clinical and preventive interventions in persons at risk for depressive and anxiety disorders. A meta-analysis on positive psychology interventions revealed that such interventions enhance well-being and decrease depressive symptoms (Bolier et al., 2013; Sin and Lyubomirsky, 2009). For instance, self-expressing and cognitive therapy may be suited to address the crystallized negative cognitions and negative expectations of the future which are pathognomonic for (remitted) depressive episodes (Sergeant and Mongrain, 2014). An earlier study of our group showed that positive mental imagery of the future is associated with higher levels of optimism (Blackwell et al., 2013). A recent study showed that the use of a mental imagery exercise, called the Best-Possible-Self exercise, can reinstate positive affect and cognitions after sad mood induction
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(Renner et al., 2014). Despite that this experiment had only been conducted among healthy participants, it opens a new venue for treatment and prevention of affective disorders. Taken together, our results show that dispositional optimism is lower in case of remitted and current anxiety and depressive disorders, inversely associated with the severity of depression, and lower in persons with a history of childhood emotional maltreatment. These factors may help to understand fluctuations of optimism over time and also identify population at risk of developing affective disorders due to lowered optimism levels. Additional longitudinal studies are needed to clarify the causality of these associations.
Role of funding source The sponsors had no role in study design and no role in data collection, data analysis, data interpretation, or writing of the manuscript. The authors had final responsibility for the decision to submit the manuscript for publication after funding.
Conflict of interest The authors declare no conflict of interest.
Acknowledgments The infrastructure for the NESDA study (www.nesda.nl) is funded through the Geestkracht program of the Netherlands Organisation for Health Research and Development (ZonMw, Grant number 10-000-1002) and is supported by Participating Universities and Mental Health Care Organizations VU University Medical Center, GGZ inGeest, Arkin, Leiden University Medical Center, GGZ Rivierduinen, University Medical Center Groningen, Lentis, GGZ Friesland, GGZ Drenthe, Scientific Institute for Quality of Health Care (IQ Healthcare), Netherlands Institute for Health Services Research (NIVEL), and Netherlands Institute of Mental Health and Addiction (Trimbos).
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Contents lists available at ScienceDirect
Journal of Affective Disorders journal homepage: www.elsevier.com/locate/jad
Research report
Long-lasting effects of affective disorders and childhood trauma on dispositional optimism Rosalie Broekhof a, Nathaly Rius-Ottenheim a,n, Philip Spinhoven a,b, Roos C. van der Mast a, Brenda W.J.H. Penninx a,c,d, Frans G. Zitman a, Erik J. Giltay a,n a
Department of Psychiatry, Leiden University Medical Center, Leiden, The Netherlands Institute of Psychology, Leiden University, Leiden, The Netherlands c Department of Psychiatry, University Medical Center Groningen, Groningen, The Netherlands d Department of Psychiatry and EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands b
art ic l e i nf o
a b s t r a c t
Article history: Received 25 July 2014 Received in revised form 13 January 2015 Accepted 14 January 2015 Available online 23 January 2015
Background: Dispositional optimism, a personality trait characterized by generalized positive expectations towards the future, is thought to remain rather stable over time. It is however largely unknown to what extent affective disorders and its risk factors affect dispositional optimism. Methods: We examined the association between (lifetime) affective disorders and childhood trauma with dispositional optimism in a sample of 2104 subjects (aged 18–65 years) from the Netherlands Study of Depression and Anxiety (NESDA). Dispositional optimism was measured with the Life Orientation Test Revised (LOT-R). Diagnoses of depressive and anxiety disorders were based on the Composite Interview diagnostic Instrument (CIDI).Childhood trauma was assessed using the Childhood Trauma Interview (CTI) and life-events with the List of Threatening Events Questionnaire (LTQ). Results: The 2104 participants were on average 46.0 (SD 13.1) years old and 65.8% were female. Multivariate analyses showed that dispositional optimism was inversely associated with current affective disorders (depression: B¼ 1.089 and anxiety: B¼ 1.066, both po0.001), but also with remitted affective disorders (depression: B¼ 0.822 and anxiety: B¼ 0.558, both po0.001) and severity of depression (B¼ 4.230; po0.001). A history of childhood emotional maltreatment (B¼ 0.905, po0.001) was related to lower optimism, whilst positive life-events were associated with higher levels of optimism (B¼ 0.235, p40.001). Limitations: The cross-sectional design hampers inferences about causality. Conclusion: Lower levels of dispositional optimism are associated with stage of affective disorders, even after remission, and a history of childhood emotional maltreatment. Identification of the risk factors contributes to understand fluctuations in dispositional optimism. & 2015 Elsevier B.V. All rights reserved.
Keywords: Dispositional optimism Childhood trauma Depression Anxiety Remitted
1. Introduction Dispositional optimism is a personality trait that refers to the extent to which individuals hold positive expectations for their future (Carver et al., 2010; Carver and Scheier, 2014). As such, it is associated with a successful adaptation in the face of stress or adversity and better health outcomes (Rasmussen et al., 2009). Although this personality trait is thought to show little variation over time (Schou et al., 2005), several factors may account for fluctuations in optimism. In addition to genetic liability (Plomin et al., 1992), increasing evidence suggests that certain environmental
n Correspondence to: Leiden University Medical Center, Department of Psychiatry, P.O. Box 9600, 2300RC, Leiden, The Netherlands. Tel.: þ31 71 5263448; fax: þ31 71 5248156. E-mail address: [email protected] (E.J. Giltay).
http://dx.doi.org/10.1016/j.jad.2015.01.022 0165-0327/& 2015 Elsevier B.V. All rights reserved.
factors may affect one's disposition to optimism (Mosing et al., 2009). Potential environmental factors include social resources, lifestyle factors and (mental) health parameters. Identification of these factors may contribute to our understanding of how optimism develops and fluctuates over time. In this study we focused on the effects of affective disorders and childhood trauma on levels of optimism. Numerous studies have found inverse associations between presence of depressive and anxiety disorders and dispositional optimism, both in cross-sectional (Colby and Shifren, 2013; Vahia et al., 2010) and longitudinal designs (Giltay et al., 2006; Vickers and Vogeltanz, 2000). One recent study hypothesized that this association might be mediated by an absence of positive cognitive bias in depressed individuals (Korn et al., 2014). In this study, participants were asked to predict the probability of experiencing adverse life events in the future. Depressed individuals showed less positive expectations than healthy controls. Furthermore, this study showed that the decreased
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positive cognitive bias was dependent on the severity of the depressive symptoms. Surprisingly, little is known about the potential lasting effects of remitted affective disorders on one's levels of dispositional optimism. Depression causes durable imbalances in motivational systems (Vergara and Roberts, 2011) and may therefore affect optimism. Interestingly, persons with remitted depression have an altered responsiveness to emotional stimuli, particularly to negative ones (Anderson et al., 2011; Merens et al., 2008). A study among 230 participants with different stages of affective disorders (remitted, current, no history) showed that participants in a remitted stage of depression displayed an attention bias for negative cues in comparison to participants with a current depression state (Anderson et al., 2011). In other words, having a history of depression seems to affect emotional processing. Consistent with these findings, previous studies among participants with a history of depression found an abnormal activity of different brain areas (the amygdala and the anterior cingulate cortex) that are involved in the imaging of (positive) future events (Morina et al., 2011). Accordingly, a previous study of our group showed that dispositional optimism was positively correlated with a higher ability to picture vividly future positive events in the mind's eye (Blackwell et al., 2013). It is therefore possible that lifetime affective disorders affect one's levels of optimism by decreasing the ability to generate mental images of future positive events. Childhood trauma has also been associated with lower levels of optimism and higher risk of affective disorders (Kessler et al., 2010). In a study among almost 20,000 Finnish workers, childhood adversities were associated with lower levels of optimism, showing a dose–response relationship (Korkeila et al., 2004). Similarly, other studies among healthy participants have found that childhood adversities were related to a lower resilience, an overarching construct including optimism, and to lower psychological wellbeing in adulthood (Herrenkohl et al., 2012; Simeon et al., 2007). A possible explanation is that adverse childhood experiences and the inability of the caregiver to provide comfort in times of need may alter cognitive assumptions and the ability to visualize positive representations of the future. In this study, we aimed to examine the association between dispositional optimism, stage of affective disorders and childhood trauma in a cohort from the NESDA-study comparing levels of optimism across groups with current, remitted and no affective disorders. We explored whether remitted (or lifetime) affective disorders affected levels of optimism and whether this association was dependent on the severity of affective disorders. We also examined the association between dispositional optimism and childhood trauma. Based on earlier results in the NESDA-cohort, we expected a stronger association of certain subtypes of childhood trauma (i.e. childhood emotional neglect) with low optimism. We hypothesized that lifetime affective disorders or childhood trauma would be associated with lower levels of dispositional optimism.
2. Material and methods 2.1. Participants Participants were recruited as part of NESDA, an ongoing longitudinal study designed to examine the long term course of depressive and anxiety disorders. The design and population characteristics have been described in detail elsewhere (Penninx et al., 2008). Briefly, NESDA included 2981 participants recruited from the community, primary care practices and specialized mental health care centers, aged between 18 and 65 years. The assessments consisted of face-toface interviews, written questionnaires, and biological measurements. For the current study, data from the 4-year follow-up wave were used as the dispositional optimism scale was introduced in
this wave. Of the initial 2981 participants, 877 (29.4%) were excluded because of being lost-to-follow-up, refusal, or missing data. The reasons for lost-to-follow-up were: 18 (0.6%) persons had died, 10.6% refused to participate, 2.2% could not be contacted, and 1.7% were unable to participate because of health reasons (Lamers et al., 2012). A total of 140 (4.7%) participants had expressed a “hard refusal” and were not contacted for a further wave. Next, 298 (10.0%) had missing items on the Life Orientation Test Revised (LOT-R) and important covariates. Thus, a total of 2104 participants had complete data on the LOT-R score and the main independent variables. The cohort of 2104 participants (age range 18–65 years) included 643 (30.6%) patients with current affective disorders, 1027 (48.8%) with lifetime affective disorders, and 434 (20.6%) controls without lifetime affective disorders. The 877 excluded participants versus 2104 included participants were similar for gender (p¼0.32) and age (p¼0.45), but had a lower level of education (11.3 [SE 0.1] versus 12.5 [SE 0.1] po0.001) and were more likely to have a current major depressive disorder (47% versus 33.4%; po0.001) at the baseline assessment. The study protocol was approved by the Ethical Review Board of each participating center and all participants signed an informed consent. 2.2. Measurements 2.2.1. Indicators of affective disorders In the NESDA study, diagnoses of depressive and anxiety disorders according to DSM-IV criteria were assessed by trained clinical staff using the CIDI lifetime version 2.1. Severity of depressive symptoms was assessed by the Inventory for Depressive Symptomatology (IDS) questionnaire. According to the IDS total score, severity of depressive symptoms was subsequently categorized into four groups: normal (o14 points), mild (14–26 points), moderate (27– 39 points), and severe (439 points) (Rush et al., 1996). For the present study, we categorized stage of affective disorders as follows: current (in the last 6 months) and remitted (lifetime non-current) diagnoses of depressive disorders (major depressive disorder and dysthymia) and anxiety disorders (panic disorder, agoraphobia, social phobia, or generalized anxiety disorder). The remitted diagnoses were identified using the combined CIDI diagnoses data from the baseline and 2 and 4 years follow-up waves. 2.2.2. Childhood trauma and life events Childhood trauma was assessed retrospectively using the Childhood Trauma Interview that has previously been used in the Netherlands Mental health Survey and Incidence Study (NEMESIS) (de Graaf et al., 2004). Participants were asked whether they had experienced any kind of emotional or psychological neglect, physical or sexual abuse before the age of 16. The definition of emotional neglect included lack of parental attention or support and ignorance of one's problems and experiences. Psychological abuse was defined as being verbally abused, undeserved punishment, subordinated to siblings, and being blackmailed. Physical abuse was defined as being kicked or hit with hands or another object, beaten up or physical abuse in any other way. Because psychological abuse and emotional neglect often occur concomitantly, we collapsed these two variables into a new variable named emotional maltreatment. Sexual abuse was defined as being sexually approached against one's will, meaning being touched or having to touch someone in a sexual way. To assess the occurrence of negative life events since the last wave, the List of Threatening Events Questionnaire (LTE-Q; Brugha and Conroy, 1985; Brugha and Cragg, 1990) was administered (e.g., ‘Serious financial troubles’, ‘Death of a first-degree relative’). The LTE-Q was extended by seven items referring to positive life events: (1) an immediate family member recovered from a serious illness; (2) met a
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Table 1 Sociodemographic and lifestyle characteristics of 2104 participants according to affective disorders status.
Age (years) Male gender Education (years) Socioeconomic resources: Married Living together with partner No. of persons in household Unemployment Income (a € 1000 netto/ month) Physical activity: Low Moderate High Smoking: Never Former Current Alcohol use: Non-drinker 1–14 glasses/wk Z 15 glasses/wk Chronic diseaseb Antidepressant use Benzodiazepine use
No lifetime affective disorders (n ¼434)
Lifetime ( 46 m) affective disorders (n¼ 1027)
Current ( r 6 m) affective disordersa (n¼ 643)
P-value
45.6 714.7 41.0% 13.0 7 3.2
45.9 7 12.9 33.1% 12.5 7 3.1
46.3 7 12.5 31.3% 12.2 7 3.3
0.70 0.002 o 0.001
48.2% 68.2%
44.5% 63.2%
40.3% 57.1%
0.009 o 0.001
2.3 71.2 29.3% 3.7 72.7
2.3 7 1.3 34.3% 2.9 7 2.0
2.2 7 1.1 45.9% 2.6 7 1.9
0.054 o 0.001 o 0.001
19.1% 43.1% 37.8%
18.9% 43.4% 37.7%
25.0% 44.9% 30.0%
0.001
39.6% 39.4% 21.0%
28.2% 40.3% 31.5%
30.5% 35.5% 34.1%
o 0.001
11.5% 86.4% 2.1% 14.7% 0.9% 1.4%
16.0% 80.9% 3.1% 18.9% 20.3% 7.7%
20.4% 73.1% 6.5% 23.2% 31.6% 21.9%
0.12
0.001 o 0.001 o 0.001
Data are percentages or mean 7 standard deviation (SD). P-values for linear trend over the three categories. a b
Current affective disorders was defined as a 6-month (6 m) anxiety or depressive disorder. Chronic disease comprised diabetes mellitus, stroke or other cardiovascular diseases, cancer, and rheumatoid arthritis.
new partner; (3) became friends; (4) have been on holiday; (5) new job or an important promotion; (6) an education completed; and (7) be better off financially. Moreover, participants could indicate the incidence of positive and negative life events not covered by the 19 standard items of the interview. 529 Of the 1209 participants indicated 1191 life events in addition to events covered by the standard 19 life events (79.6% 1; 17.0% 2; 2.6% 3; and 0.8% 4 additional events). These extra events were scored by two independent raters (two master students psychology) as belonging to one of the standard 19 life event categories (n¼522) or as presenting a different type of positive (n¼ 301; e.g., marriage, birth of a child), negative life events (n¼ 305; e.g., divorce of child, dead of a pet) or non-classifiable event (n¼ 63). Only in 36 (3.0%) of the ratings the two raters disagreed and had to reach consensus. In the total sample the direction of the correlations of individual positive and negative life events with 1-month recency diagnosis of depressive and/or anxiety disorder was in accordance with the a priori normatively defined valence of the life event items with negative life events showing a positive correlation and positive life events a negative correlation with depressive and anxiety diagnoses. Consequently, negative and positive life events during the 2year follow-up period (both the standard events on the LTE-Q as well as the additionally reported events) were summed in order to derive two separate measures, one for the total number of negative (range 0–16) and one for the total number of positive life events (range 0–11). The two subscales proved to be totally unrelated, r ¼0.04, ns. In addition, positive as well as negative life events were dated in months starting from baseline and used as time-dependent covariates.
2.2.3. Dispositional optimism Dispositional optimism was assessed using the LOT-R that consists of 10 items rated on a five-point Likert scale, with 6 items
yielding an optimism score and 4 filler items not used in scoring (Glaesmer et al., 2012). Participants were asked to indicate the extent of their agreement with each of the items on a 0–4 point scale. Three negatively coded items needed to be reversed coded. The total LOT-R score ranges from 0 to 24 points, with higher scores being indicative of a higher level of optimism. For the computation of optimism scores one missing item per subject was allowed. In this study the Cronbach's alpha was 0.87. Dispositional optimism was used in this study as a continuous variable. 2.2.4. Covariates Sociodemographic and lifestyle characteristics were obtained through standardized questionnaires. This information included age, gender, and years of education. Smoking status was classified as no smoking, former smoking, and current smoking. Physical activity was assessed using the International Physical Activity Questionnaire (Booth, 2000) and categorized into low, moderate and high. Alcohol use was categorized as non-drinker, moderate drinker (1–14 glasses a week), and heavy drinker ( 415 glasses a week). The prevalent diagnoses of cardiovascular disease, cancer, stroke and diabetes mellitus were assessed by standardized questionnaires, and number of chronic diseases was calculated. 2.3. Statistical analyses A one-way analysis of variance was conducted to explore the association between stages of affective disorders, defined as no lifetime affective disorders, lifetime affective disorders and current affective disorders, and sociodemographic and lifestyle characteristics. Descriptive data are presented as numbers and percentages for categorical variables and means with standard deviations for normally distributed, continuous variables (Table 1). Linear regression analyses were used to examine the association between dispositional optimism and sociodemographic
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and lifestyle characteristics in persons without affective disorders to yield the potential confounders in this population. The association was also explored in an adjusted model, including the following covariates: gender, age, years of education, and physical activity (Table 2). Also multivariate linear regression analyses were used to assess the association of optimism with presence and severity of affective disorders (using the IDS-SR) in the whole sample. An additional linear regression analysis was conducted to explore the association between each of the subtypes of childhood trauma, life events and dispositional optimism. To explore the independent effect of each type of maltreatment, we used a forced entry in which we introduced all three subtypes as predictors of the model. Both analyses were repeated in adjusted models in which the abovementioned covariates were taken into account. To test for multicollinearity, the Variance Inflation Factor (VIF) score was examined for each variable in each model. We used the arbitrary rule of thumb cut-off criterion of 2 for deciding when a given independent variable displayed multicollinearity. As the variable emotional neglect and psychological abuse approached this cut off (i.e., VIF of 1.958), we decided to collapse them into one emotional maltreatment variable as has previously been done (van Harmelen et al., 2010). Finally, we examined the interactions between childhood maltreatment and affective disorders by adding the appropriate interaction terms to the multivariable model. However, we found no evidence of significant interaction terms (both p's 4 0.20). All p-Values are two tailed and considered statistically significant at the level of p o0.05. Data analyses were performed using SPSS version 20.0 (Chicago, IL) for Windows.
3. Results Table 1 shows the sociodemographic and lifestyle characteristics according to the stage of affective disorders. The 2104 participants were on average 46.0 (SD 13.1) years old and 65.8% were female. Of the 2104 participants, 643 (30.6%) met criteria of current affective disorders, 1027 (48.8%) for lifetime affective disorders, and 434 (20.6%) had no lifetime affective disorders. The participants without current affective disorders had received more years of education. The socio-economic profile was less favorable in the group with current affective disorders, as these participants were less likely to be married, were more likely to be unemployed, and had a lower income than the participants without current affective disorders. Current affective disorders were also associated with unhealthy lifestyle behaviors as participants from this group were more likely to be current smokers and had a lower level of physical activity. As expected, current affective disorders was also associated with a higher prevalence of chronic physical illnesses and with the use of antidepressants and benzodiazepines. Table 2 reports the associations between sociodemographic and lifestyle characteristics and dispositional optimism in participants without current affective disorders. Higher levels of optimism were independently associated with more years of education, more physical activity, and having less frequently a history of affective disorders (i.e., anxiety and depressive disorder), which were included in the subsequent multivariable models. We additionally repeated these analyses on the healthy subpopulation, finding that higher physical activity and a higher level of education were the significant independent correlates of dispositional optimism. We also examined the distribution of dispositional optimism in our sample (data not shown). When we considered the outermost 5% of observations to define limits for one-sided reference
Table 2 Associations with optimism in 1461 participants without current affective disordersa. Unadjusted
Age (per year) Male gender Education (years) Socioeconomic resources: Married Living together with partner No. of persons in household Not working Income (per € 1000/month) Physical activity: Low Moderate High Smoking status: Never Former Current Alcohol use: Non-drinker 1–14 glasses/wk Z15 glasses/wk Chronic diseaseb Remitted affective disorders Antidepressant use Benzodiazepine use
Adjusted
B 7 SE
P-value
B 7SE
P-value
0.0107 0.006 0.082 7 0.171 0.164 70.025
0.11 0.63 o 0.001
0.004 70.007 0.166 7 0.167 0.129 70.027
0.57 0.32 o 0.001
0.253 7 0.164 0.5337 0.170 0.1447 0.066 0.4647 0.174 0.206 70.036
0.12 0.002 0.03 0.008 o 0.001
0.036 7 0.232 0.3167 0.240 0.036 7 0.078 0.0457 0.184 0.077 70.041
0.88 0.19 0.65 0.81 0.06
Ref. 0.0117 0.165 0.390 7 0.168
0.95 0.02
Ref. 0.284 7 0.218 0.628 7 0.221
0.190 0.005
Ref. 0.340 7 0.167 0.649 70.181
0.04 o 0.001
Ref. 0.191 70.192 0.187 70.208
0.32 0.37
Ref. 0.438 7 0.215 0.584 7 0.495 0.4827 0.214 1.906 70172 1.1167 0.230 1.1117 0.348
0.04 0.24 0.02 o 0.001 o 0.001 0.001
0.066 7 0.230 0.0747 0.519 0.164 7 0.218 1.658 7 0.180 0.393 7 0.231 0.3797 0.342
0.77 0.89 0.45 o 0.001 0.09 0.27
Data are presented as beta coefficients and standard errors. Adjusted: all the variables are included in the adjusted model. a b
Current affective disorders was defined as a 6-month (6 m) anxiety or depressive disorder. Chronic disease comprised diabetes mellitus, stroke or other cardiovascular diseases, cancer, and rheumatoid arthritis.
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355
Cumulative prevalence (%)
100 LOT-R score: 16>–24 (highest optimism) 12>–16 8>–12 4>–8 0–4 (lowest optimism)
80
60
40
20
Co ntr ol g (n= roup 43 4) Re mi tte d (n= grou 10 p 27 An ) xie ty dis or de r (n= only De 25 pre 4) ss ive dis ord er (n= only 18 2) Co mo rb id g (n= roup 20 7)
0
Cumulative prevalence (%)
100 LOT-R score: 16>–24 (highest optimism) 12>–16 8>–12 4>–8 0–4 (lowest optimism)
80
60
40
20
mo n (n= ths 83 ) 6-1 2
12 -24 mo n (n= ths 73 )
-72 mo (n= nths 35 8) 24
>7
2m o (n= nths 53 1)
0
Time past since last episode Fig. 1. Cumulative prevalence of optimism scores depending on the presence of affective disorders.
intervals (95th percentiles; P95), we found a cut off value of 11 in the group without a history of affective disorders. Fig. 1 shows the cumulative prevalence of optimism scores depending on the presence of affective disorders. Participants with no lifetime affective disorders (i.e. control group) were overall the most optimistic group of subjects, also when compared to subjects with remitted affective disorders. Participants with either an anxiety or a depressive disorder were overall less optimistic, with those with a depressive disorder scoring slightly lower on optimism. Participants with a comorbid anxiety and depressive disorder showed the poorest levels of optimism. In a subanalysis within the remitted group, we found that participants who had suffered a depressive episode within the time span of only 6 to 12 months before measurement had the lowest optimism levels, which gradually improved as the time elapsed since the last depressive episode was longer (P o0.001 by chi-squared test).
Multivariate linear regression analyses were conducted to examine the associations between anxiety and depression disorders and dispositional optimism, depending on severity and stage of affective disorders (Fig. 2). The severity of depressive symptoms (i.e. IDS-SR total score) was inversely associated with levels of dispositional optimism, even after adjustment for confounders (B¼ 4.230; po0.001). Furthermore, persons who met criteria of affective disorders displayed lower optimism scores in comparison to persons who were free of current affective disorders (depression: B¼ 1.089 and anxiety: B¼ 1.066, both p'so0.001). This association was not only present in persons with current affective disorders, but also in persons with lifetime affective disorders (depression: B¼ 0.822 and anxiety: B¼ 0.558, both p'so0.001). Table 3 shows the results of the linear regression analyses on the associations between childhood trauma subtypes and life-events with dispositional optimism. In the unadjusted models, optimism
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Fig. 2. Effects of affective disorders on dispositional optimism in 2104 participants. Data are presented as B-coefficients and standard errors (SE), and in forest plots as mean B-coefficients with error bars indicating the 95% confidence, intervals. The severity of depressive symptoms was categorized according to IDS-SR scores (normal o 14 points, mild 14–26 points, moderate 27–39 points, and severe 439 points). Mean values, standard errors (SE), and P-values are obtained by linear regression analyses, adjusted for gender, age, years of, education, and physical activity, as well as all other variables in this table. Table 3 Effects of childhood trauma and recent life events on dispositional optimism in 2104 subjects. Unadjusted
Emotional maltreatment Physical abuse Sexual abuse No. negative life events since 2 yr No. positive life events since 2 yr
Adjusted
B 7SE
P-value
B7 SE
P-value
–2.4747 0.230 1.6437 0.290 0.698 7 0.239 0.298 7 0.056 0.3517 0.056
o0.001 o0.001 0.004 o0.001 o0.001
0.9057 0.249 0.4017 0.295 0.098 7 0.213 0.048 7 0.051 0.2357 0.055
o 0.001 0.18 0.64 0.34 o 0.001
Data are presented as B-coefficients and standard errors (SE). Childhood trauma variables are scores that range from 0 (i.e., no) to 0.5 (i.e., once or sometimes) to 1.0 (regularly, often or very often). Emotional maltreatment was calculated as the mean of emotional neglect and psychological abuse (because of the strong association between both forms of childhood maltreatment). P-values are obtained by linear regression analyses, adjusted for gender, age, years of education, physical activity, severity of depressive symptoms, depressive disorders (i.e., never/remitted/current), anxiety disorders (i.e., never/remitted/current), and each of the other two forms of childhood trauma.
was inversely associated with all subtypes of childhood trauma. However, these associations were substantially weakened after adjusting for important sociodemographic, clinical and lifestyle characteristics and other childhood trauma subtypes. Only emotional maltreatment showed an independent association with optimism scores over and above the effect of possible confounders and other abuse types (B-coefficient¼ 0.905; SE 0.249; po0.001). We found that positive life events were predictive of higher optimism scores (B-coefficient¼0.235; SE 0.055; po0.001), but that negative life events were not.
4. Discussion The present study shows an association between low optimism and presence of affective disorders. Interestingly, a history of affective disorders was associated with lower levels of optimism, even after achieving remission. There was a dose–response relationship between the severity of depressive symptoms, time elapsed since the last episode, and levels of optimism. In other words, a more severe and a more recent depressive episode were associated with lower levels of optimism. Furthermore, an association was found between lower levels of optimism and childhood trauma, particularly with childhood emotional maltreatment. Our finding of an inverse association between depressive symptoms and dispositional optimism is in line with some earlier results (Giltay et al., 2006). Our study elaborates on the results of Korn et al. replicating their finding of an inverse association between dispositional optimism and depressive symptoms (Korn et al., 2014). As in their study, we also found that more severely depressed persons displayed lower levels of optimism. In our study we went one step further by exploring the association in a larger sample and including stage of affective disorders. In this regard, we found that not only current affective disorders, but also remitted affective disorders were
associated with lower levels of optimism. It is possible that remitted patients may realize that they are at increased risk for future relapse and may therefore rationally hold less optimistic beliefs. Maladaptive cognitive bias may be the clue to interpret these associations. It is possible that a depressive episode alters the appraisal of negative and positive cues, leading to a different interpretation of events and changing individual's expectations towards the future. This mechanism may explain why formerly depressed are more prone to new depressive episodes as they have fewer buffers. Depression may erode optimistic cognitive styles and reduce coping abilities. Once crystallized, negative representations may be more difficult to alter than positive representations (Joiner, 2000). As a result, the levels of dispositional optimism may decrease after an episode of a depressive or anxiety disorder. This association has also a biological substrate since neuroimaging studies have found microstructural changes and an abnormal connectivity in the amygdala among persons with a major depression, even after achieving remission (Arnold et al., 2012). These are the same brain regions that show enhanced activity in individuals with higher levels of optimism (Sharot et al., 2007). The amygdala is involved in recalling past (threatening) events that are reconstructed to form representations of possible future scenarios (Addis et al., 2007). In accordance with these results, one could hypothesize that a depressive episode may change neuronal networks that are involved in the projection and appraisal of future positive events. However, our results also suggest that changes in cognitive appraisals may dissipate over time. We found that levels of optimism were higher the longer the time elapsed since the last depressive episode. In our study, childhood emotional maltreatment was also associated with lower levels of optimism, even after adjustment for confounders. It has previously been found that caregiver's emotional coldness and the inability to empathize may lead to long-lasting psychological adverse effects, such as emotional and cognitive disturbances (Norman et al., 2012). Only when the
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traumatic event is overcome successfully, it does result in posttraumatic growth and strengthens optimism (Bostock et al., 2009). Otherwise, failure to overcome the traumatic event results in disengagement and a lower perception of self-mastery and, possibly, lower levels of optimism. Earlier studies based on the NESDA cohort have shown that childhood emotional abuse is associated with negative cognitive styles. In line with our findings, these studies described a stronger association for childhood emotional maltreatment than for childhood sexual or physical abuse (van Harmelen et al., 2010). In their discussion, the authors argued that childhood emotional maltreatment may be more strongly associated with negative cognitions since in this subtype of abuse negative self-associations are explicitly handed to the child. Trauma-induced generalized negative cognitive schemas may alter the emotional self-regulation that underlies optimistic outcome expectancies. It is thought that these psychological outcomes are the result of alterations in neurobiological development. Again, neuroimaging studies have found higher amygdala responsiveness to negative cues in individuals with a history of childhood maltreatment (Dannlowski et al., 2013). Abused individuals seem to be caught in a negative loop, where emotional abuse leads to a negative cognitive bias, which results in a negative representation of future events. We found that sporadic but not more frequent psychological and physical abuse was associated with lower optimism. This may be due to the fact that we also adjusted for the severity of depressive symptoms, which may have somewhat over-adjusted the effects of low mood states, as these may be a consequence of trauma-induced low optimism. There are some limitations to the study at hand that should be discussed. First, the cross-sectional design of our study limits causal inference of the directional routes of these associations. Next, it could be argued that the association between low dispositional optimism and childhood emotional maltreatment might have arisen from a recall bias due to the retrospective report of childhood trauma. Yet, childhood trauma was measured at the baseline assessment, four years before the assessment of dispositional optimism and current affective disorders, which may have reduced recall bias and reverse causation. Also, the incidence of life events was reported retrospectively and we did not verify these events or whether other life events were missing. Another limitation is that we could not test whether the associations were mediated or moderated by other psychological dimensions like self-esteem. The main strength of this study lies in its large sample size, the use of validated diagnoses based on structured diagnostic interviews (i.e., CIDI) to determine (history of) affective disorders and the use of a semi-structured interview to assess different types of childhood abuse. Dispositional optimism was measured with the Life Orientation Test Revised, a validated and internally consistent instrument. Our study design enabled us to analyze associations by taking into account the effect of current and remitted diagnoses of depressive or anxiety disorders, childhood trauma and the severity of these symptoms. Our results may provide a basis for clinical and preventive interventions in persons at risk for depressive and anxiety disorders. A meta-analysis on positive psychology interventions revealed that such interventions enhance well-being and decrease depressive symptoms (Bolier et al., 2013; Sin and Lyubomirsky, 2009). For instance, self-expressing and cognitive therapy may be suited to address the crystallized negative cognitions and negative expectations of the future which are pathognomonic for (remitted) depressive episodes (Sergeant and Mongrain, 2014). An earlier study of our group showed that positive mental imagery of the future is associated with higher levels of optimism (Blackwell et al., 2013). A recent study showed that the use of a mental imagery exercise, called the Best-Possible-Self exercise, can reinstate positive affect and cognitions after sad mood induction
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(Renner et al., 2014). Despite that this experiment had only been conducted among healthy participants, it opens a new venue for treatment and prevention of affective disorders. Taken together, our results show that dispositional optimism is lower in case of remitted and current anxiety and depressive disorders, inversely associated with the severity of depression, and lower in persons with a history of childhood emotional maltreatment. These factors may help to understand fluctuations of optimism over time and also identify population at risk of developing affective disorders due to lowered optimism levels. Additional longitudinal studies are needed to clarify the causality of these associations.
Role of funding source The sponsors had no role in study design and no role in data collection, data analysis, data interpretation, or writing of the manuscript. The authors had final responsibility for the decision to submit the manuscript for publication after funding.
Conflict of interest The authors declare no conflict of interest.
Acknowledgments The infrastructure for the NESDA study (www.nesda.nl) is funded through the Geestkracht program of the Netherlands Organisation for Health Research and Development (ZonMw, Grant number 10-000-1002) and is supported by Participating Universities and Mental Health Care Organizations VU University Medical Center, GGZ inGeest, Arkin, Leiden University Medical Center, GGZ Rivierduinen, University Medical Center Groningen, Lentis, GGZ Friesland, GGZ Drenthe, Scientific Institute for Quality of Health Care (IQ Healthcare), Netherlands Institute for Health Services Research (NIVEL), and Netherlands Institute of Mental Health and Addiction (Trimbos).
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