Similarities in diagnostic comorbidity between suicide among young people in Sweden and the United States Rich CL, Runeson BS. Similarities in diagnostic comorbidity between suicide among young people in Sweden and the United States. Acta Psychiatr Scand 1992: 86: 335-339. 0 Munksgaard 1992. A significant difference in the prevalence of personality disorders was reported between similar studies of suicide among young people (under age 30) performed in San Diego, California (10% of 133 cases), and Gdteborg, Sweden (34% of 58 cases). The difference was due entirely to the absence of borderline personality disorder (BPD) reported in the San Diego sample. In this study, we used preselected variables to reassess the suicides from the San Diego study for criteria consistent with BPD. We found that 41 % met the criteria, which was now not significantly different from the Goteborg sample. Comparisons among a number of other demographic, social, and diagnostic variables revealed many similarities in the two samples, particularly Axis I comorbidity with depression and/or substance abuse and Axis I1 comorbidity with antisocial personality disorder. We conclude that the characteristics associated with BPD identify similar young persons who committed suicide in Sweden and the United States. Questions remain as to whether or not Axis I and I1 disorders are independent in relation to suicide. The comorbidity pattern described here must be considered seriously in the clinical setting for its fatal implications.
At least 6 major studies of unselected consecutive suicides that have used systematic structured interview formats to derive formal psychiatric diagnostic assessments have been reported in English-language journals since 1958 (1-6). There have also been several similar studies of selected subpopulations of consecutive suicides: men (7), women (8) and young people (9, 10). All 9 studies found that the vast majority of the people who committed suicide had at least one mental disorder (Table 1). In spite of differences in the diagnostic methodology and criteria, depression and substance abuse (particularly alcoholism, with one exception (6)) were consistently found in high proportions of these consecutive suicides. Reporting of personality disorder (PD) among suicides has been somewhat less consistent, however, ranging from 0 % to 34 % but frequently in the 5 %-lo% range (Table 1). Most of this variation is probably accounted for by differences in the definitions of diagnostic criteria and application of the criteria over time and in different geographic locations. The reported rate of 34% P D using DSM111-Rcriteria (1 1) in the 58 consecutive youth suicides from Goteborg, Sweden (12) stands out, particularly in contrast with the 10% rate of P D in
C. L. Rich ’, B. S. Runeson’
’
Department of Psychiatry, University of South Alabama, Mobile, USA, Sahlgrenska Hospital, University of Goteborg, Sweden
Key words: suicide; personality disorder; comorbidity C.L. Rich M.D., Department of Psychiatry, University of South Alabama College of Medicine, 3421 Medical Park Drive West, Suite 2, Mobile, AL 36693, USA Accepted for publication May 17, 1992
Table 1. Mental disorders in systematic interview studies of suicide Years of study
n
Any mental disorder
Personality disorder
Unselected consecutive cases Robins etal. (1) (St. Louis) Dorpat & Ripley (2) (Seattle) Barraclough et al. (3) (London) Chynoweth et al. (4) (Brisbane) Rich et al. (5) (San Diego) Arath et al. (6) (Budapest)
1956-1957 1957-1958 1966-1968 1973-1974 1981-1983 1985
134 114 100 135 204 200
126 (94%) 108 (95%) 93 (93%) 119 (88%) 193 (95%) 162 (82%)
Oa 10 (9%) 27 (27%) 4 (3%) 11 (5%) Ob
Males - all ages Beskow (7) (Sweden) Rich et al. (5) (San Diego)
1970-1 97 1 1981-1983
27 1 143
262 (97%) 133 (93%)
12 (5%) 7 (5%)
Females - all ages Asgird (8) (Stockholm) Rich et al. (5) (San Diego)
1982 1981-1 983
104 61
95 (91%I 60 (98%)
4 (4%) 4 (7%)
Under age 30 - males and females Rich et al. (9) (San Diego) 198 1-1983 Runeson (10) (Goteborg) 1984-1987
133 58
122 (92%) 57 (98%)
13 (10%) 20 (34%)
a
No criteria included. Axis II disorders not reported.
the comparable age group of suicides in San Diego, California (9). The San Diego study, using DSM-I11 (13) criteria, is more consistent with earlier reports. A recent report from Finland (14), however, that
335
Rich & Runeson
also used DSM-111-R criteria diagnosed P D in 32% of the 53 suicides among people aged 13-19 years. Case-by-case comparison between the Goteborg and San Diego studies indicates that the proportion of cases with antisocial personality disorder (ASPD) was similar (15% vs 10%) and the difference was essentially made up by borderline personality disorder (BPD). Similar case-by-case comparisons could not be done with the Finnish study because of the way those data are presented. In contrast to this difference in pattern of P D between the Goteborg and San Diego youth suicides, an interesting similarity was found. Eighteen of the 20 Goteborg suicides with a P D (10) and 12 of the 13 San Diego (9) suicides with a P D also had a comorbid Axis I disorder (Table 2). The predominant Axis I disorders in both groups were depression (35% and 54% respectively) and substance abuse or dependence (70% and 92% respectively). These preliminary comparisons suggested at least two possible explanations to us for the disparity in diagnosed P D between San Diego and Goteborg. The first is that there may have been real differences in the psychiatric diagnostic characteristics of youth suicides in the two locations. A second explanation is that there may have been differences in rates of detection, particularly of BPD, due to methodological differences. This second explanation seemed more likely to us for several reasons. First, the San Diego study, while comprehensive in its data collection, was clearly designed to focus on a possible relationship between substance abuse and the increase in youth suicides over the past several decades. Second, although neither study used an existing structured diagnostic interview format for Table 2. Personality disorders in suicides among youth in San Diego Axis I comorbidity
Age
Sex
Personality disordera
20 21 21 21 24 24 25 26 26 21 21 21 29
F M M F M F M M M M F M M
ASPD ASPD ASPD ASPD ASPD MPD ASPD ASPD ASPD ASPD ASPD ASPD ASPD
a
Affectiveb
Psychotic'
t t
t t t
t t t
t t
t t t t t t t t t t t
Insufficient information
t
ASPD=antisocial personality disorder; MPD=mixed personality disorder. Major depression, atypical depression, schizoaffective and dysthymia. Schizophrenia and atypical psychosis. Alcohol and/or other drug abuse and/or dependence.
336
Substance abused
t
BPD or P D in general, the Goteborg study had the advantage of a few more years of experience with the developing DSM-I11 and DSM-111-R diagnostic criteria for PD. Third, the similarities in pattern of Axis I comorbidity among the P D cases between the two studies seems more indicative of clinical similarity than difference. In order to investigate the possibility of differential detection, then, we reassessed the San Diego sample of 133 young suicides and identified cases that might have possibly met criteria for BPD but were not diagnosed as such in the original data analysis. We then compared the cases to the 19 BPD cases from the Goteborg sample of 58 young suicides, looking specifically at the question of mental comorbidity. We also compared the two samples on some demographic and family variables. Material and methods
The California sample included 133 consecutive suicides (99 males, 34 females) under age 30 that occurred in San Diego County between November 1981 and June 1983. The method of this study has been reported in detail elsewhere (9). Information was obtained from family members, friends, employers, physicians, and other professionals generally within a period of 1 to 3 months following the death. Information was also sought from hospital, school, police and other records. A structured interview containing over 300 items covering demographic data, clinical signs and symptoms, stressors at the time of death, past history, medical history and family history was used to record the information. Diagnoses of mental disorders were derived by a consensus of two investigators using DSM-I11 criteria (1 1). The Swedish sample included 58 consecutive suicides (42 males, 16 females) between the ages of 15-29 that occurred in the city of Goteborg from July 1984 to June 1987. The method ofthis study has also been reported in detail elsewhere (10). A systematic interview format covering clinical signs and symptoms, family and childhood factors, educational and employment history, medical history and prior suicidal behavior was used to gather data from informants. The median time for conducting interviews was 9 weeks after the suicide. Information was also sought from hospital, school, police and other records. Mental disorders were diagnosed by consensus of the authors and Jan Beskow using DSM111-R criteria (13). The complete list of variables from the San Diego study was reviewed by both authors. Items were selected as indicators of possible inclusion in the categories of DSM-111-R diagnostic criteria for BPD (Table 3). Such items were available for 6 of the 8
Comorbidity in youth suicide Table 3. Variables included in reassessment of San Diego cases 8PD criterion 0
0
Unstable, intense interpersonal relationships (any one variable)
Potentially self-damaging impulsiveness (2 or more variables)
Study cases
Variables selected Many friends, none close Difficulty adjusting to disrupted relationships or deaths More than 1 divorce More than 2 separations in current relationship Persistent or recurrent fights or separations with significant others Spending sprees Gambling problems Promiscuity Extramarital affairs Convicted of crime Substance abuse
Marked affective instability (either variable)
Major mood swings Nervous apprehension
0
Inappropriate intense anger (any one variable)
Irritability Threats to harm others Major quarrels with parent, spouse, or other persons
0
Recurrent suicidal or self-mutilating behavior
More than one self-injurious act
0
Marked and persistent identity disturbance (2 or more variables)
No "usual" occupation Irregularly employed No job held over 1 year Usually quit jobs without new one Sexual identity disturbance
0
Chronic emptiness or boredom
No variables identified
0
Frantic efforts to avoid abandonment
No variables identified
0
Table 4. Selected diagnostic categories
criteria. The cases were then scored as to the number of categories in which they had the selected indicators. The San Diego cases scoring positive in 4 or more of the 6 criteria were compared with the 19 Goteborg BPD cases for frequencies of any Axis I disorder, depression, and substance abuse. The two samples were also compared for some social and family characteristics that had been previously described in the Gdteborg study. Comparisons were also made between each study group and the rest of the suicides in its respective sample. Tests used in statistical comparisons are indicated in the text or tables. All chi-square tests included Yates' correction for continuity. The df = 1 for all chi-square tests. All probabilities of
At least 6 major studies of unselected consecutive suicides that have used systematic structured interview formats to derive formal psychiatric diagnostic assessments have been reported in English-language journals since 1958 (1-6). There have also been several similar studies of selected subpopulations of consecutive suicides: men (7), women (8) and young people (9, 10). All 9 studies found that the vast majority of the people who committed suicide had at least one mental disorder (Table 1). In spite of differences in the diagnostic methodology and criteria, depression and substance abuse (particularly alcoholism, with one exception (6)) were consistently found in high proportions of these consecutive suicides. Reporting of personality disorder (PD) among suicides has been somewhat less consistent, however, ranging from 0 % to 34 % but frequently in the 5 %-lo% range (Table 1). Most of this variation is probably accounted for by differences in the definitions of diagnostic criteria and application of the criteria over time and in different geographic locations. The reported rate of 34% P D using DSM111-Rcriteria (1 1) in the 58 consecutive youth suicides from Goteborg, Sweden (12) stands out, particularly in contrast with the 10% rate of P D in
C. L. Rich ’, B. S. Runeson’
’
Department of Psychiatry, University of South Alabama, Mobile, USA, Sahlgrenska Hospital, University of Goteborg, Sweden
Key words: suicide; personality disorder; comorbidity C.L. Rich M.D., Department of Psychiatry, University of South Alabama College of Medicine, 3421 Medical Park Drive West, Suite 2, Mobile, AL 36693, USA Accepted for publication May 17, 1992
Table 1. Mental disorders in systematic interview studies of suicide Years of study
n
Any mental disorder
Personality disorder
Unselected consecutive cases Robins etal. (1) (St. Louis) Dorpat & Ripley (2) (Seattle) Barraclough et al. (3) (London) Chynoweth et al. (4) (Brisbane) Rich et al. (5) (San Diego) Arath et al. (6) (Budapest)
1956-1957 1957-1958 1966-1968 1973-1974 1981-1983 1985
134 114 100 135 204 200
126 (94%) 108 (95%) 93 (93%) 119 (88%) 193 (95%) 162 (82%)
Oa 10 (9%) 27 (27%) 4 (3%) 11 (5%) Ob
Males - all ages Beskow (7) (Sweden) Rich et al. (5) (San Diego)
1970-1 97 1 1981-1983
27 1 143
262 (97%) 133 (93%)
12 (5%) 7 (5%)
Females - all ages Asgird (8) (Stockholm) Rich et al. (5) (San Diego)
1982 1981-1 983
104 61
95 (91%I 60 (98%)
4 (4%) 4 (7%)
Under age 30 - males and females Rich et al. (9) (San Diego) 198 1-1983 Runeson (10) (Goteborg) 1984-1987
133 58
122 (92%) 57 (98%)
13 (10%) 20 (34%)
a
No criteria included. Axis II disorders not reported.
the comparable age group of suicides in San Diego, California (9). The San Diego study, using DSM-I11 (13) criteria, is more consistent with earlier reports. A recent report from Finland (14), however, that
335
Rich & Runeson
also used DSM-111-R criteria diagnosed P D in 32% of the 53 suicides among people aged 13-19 years. Case-by-case comparison between the Goteborg and San Diego studies indicates that the proportion of cases with antisocial personality disorder (ASPD) was similar (15% vs 10%) and the difference was essentially made up by borderline personality disorder (BPD). Similar case-by-case comparisons could not be done with the Finnish study because of the way those data are presented. In contrast to this difference in pattern of P D between the Goteborg and San Diego youth suicides, an interesting similarity was found. Eighteen of the 20 Goteborg suicides with a P D (10) and 12 of the 13 San Diego (9) suicides with a P D also had a comorbid Axis I disorder (Table 2). The predominant Axis I disorders in both groups were depression (35% and 54% respectively) and substance abuse or dependence (70% and 92% respectively). These preliminary comparisons suggested at least two possible explanations to us for the disparity in diagnosed P D between San Diego and Goteborg. The first is that there may have been real differences in the psychiatric diagnostic characteristics of youth suicides in the two locations. A second explanation is that there may have been differences in rates of detection, particularly of BPD, due to methodological differences. This second explanation seemed more likely to us for several reasons. First, the San Diego study, while comprehensive in its data collection, was clearly designed to focus on a possible relationship between substance abuse and the increase in youth suicides over the past several decades. Second, although neither study used an existing structured diagnostic interview format for Table 2. Personality disorders in suicides among youth in San Diego Axis I comorbidity
Age
Sex
Personality disordera
20 21 21 21 24 24 25 26 26 21 21 21 29
F M M F M F M M M M F M M
ASPD ASPD ASPD ASPD ASPD MPD ASPD ASPD ASPD ASPD ASPD ASPD ASPD
a
Affectiveb
Psychotic'
t t
t t t
t t t
t t
t t t t t t t t t t t
Insufficient information
t
ASPD=antisocial personality disorder; MPD=mixed personality disorder. Major depression, atypical depression, schizoaffective and dysthymia. Schizophrenia and atypical psychosis. Alcohol and/or other drug abuse and/or dependence.
336
Substance abused
t
BPD or P D in general, the Goteborg study had the advantage of a few more years of experience with the developing DSM-I11 and DSM-111-R diagnostic criteria for PD. Third, the similarities in pattern of Axis I comorbidity among the P D cases between the two studies seems more indicative of clinical similarity than difference. In order to investigate the possibility of differential detection, then, we reassessed the San Diego sample of 133 young suicides and identified cases that might have possibly met criteria for BPD but were not diagnosed as such in the original data analysis. We then compared the cases to the 19 BPD cases from the Goteborg sample of 58 young suicides, looking specifically at the question of mental comorbidity. We also compared the two samples on some demographic and family variables. Material and methods
The California sample included 133 consecutive suicides (99 males, 34 females) under age 30 that occurred in San Diego County between November 1981 and June 1983. The method of this study has been reported in detail elsewhere (9). Information was obtained from family members, friends, employers, physicians, and other professionals generally within a period of 1 to 3 months following the death. Information was also sought from hospital, school, police and other records. A structured interview containing over 300 items covering demographic data, clinical signs and symptoms, stressors at the time of death, past history, medical history and family history was used to record the information. Diagnoses of mental disorders were derived by a consensus of two investigators using DSM-I11 criteria (1 1). The Swedish sample included 58 consecutive suicides (42 males, 16 females) between the ages of 15-29 that occurred in the city of Goteborg from July 1984 to June 1987. The method ofthis study has also been reported in detail elsewhere (10). A systematic interview format covering clinical signs and symptoms, family and childhood factors, educational and employment history, medical history and prior suicidal behavior was used to gather data from informants. The median time for conducting interviews was 9 weeks after the suicide. Information was also sought from hospital, school, police and other records. Mental disorders were diagnosed by consensus of the authors and Jan Beskow using DSM111-R criteria (13). The complete list of variables from the San Diego study was reviewed by both authors. Items were selected as indicators of possible inclusion in the categories of DSM-111-R diagnostic criteria for BPD (Table 3). Such items were available for 6 of the 8
Comorbidity in youth suicide Table 3. Variables included in reassessment of San Diego cases 8PD criterion 0
0
Unstable, intense interpersonal relationships (any one variable)
Potentially self-damaging impulsiveness (2 or more variables)
Study cases
Variables selected Many friends, none close Difficulty adjusting to disrupted relationships or deaths More than 1 divorce More than 2 separations in current relationship Persistent or recurrent fights or separations with significant others Spending sprees Gambling problems Promiscuity Extramarital affairs Convicted of crime Substance abuse
Marked affective instability (either variable)
Major mood swings Nervous apprehension
0
Inappropriate intense anger (any one variable)
Irritability Threats to harm others Major quarrels with parent, spouse, or other persons
0
Recurrent suicidal or self-mutilating behavior
More than one self-injurious act
0
Marked and persistent identity disturbance (2 or more variables)
No "usual" occupation Irregularly employed No job held over 1 year Usually quit jobs without new one Sexual identity disturbance
0
Chronic emptiness or boredom
No variables identified
0
Frantic efforts to avoid abandonment
No variables identified
0
Table 4. Selected diagnostic categories
criteria. The cases were then scored as to the number of categories in which they had the selected indicators. The San Diego cases scoring positive in 4 or more of the 6 criteria were compared with the 19 Goteborg BPD cases for frequencies of any Axis I disorder, depression, and substance abuse. The two samples were also compared for some social and family characteristics that had been previously described in the Gdteborg study. Comparisons were also made between each study group and the rest of the suicides in its respective sample. Tests used in statistical comparisons are indicated in the text or tables. All chi-square tests included Yates' correction for continuity. The df = 1 for all chi-square tests. All probabilities of
