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Recent life events and completed suicide in bipolar affective disorder. A comparison with major depressive suicides
ELSEVIER
Journal
of Affective
Disorders
33 (19%) 99-106
Recent life events and completed suicide in bipolar affective disorder. A comparison with major depressive suicides Erkki IsometsS ‘t*, Martti Heikkinen a, Markus Henriksson Jouko tinnqvist a
‘vh,Hillevi Aro ‘,
” Department of Menial Health, National Public Health Institute, Mannerheimintie ’ Department Received
166, FIN-00300 Helsinki. Finland of Psychiatry, Helsinki Unicwsiry, Helsinki, Finland
5 July 1994; revised
19 September
1994: accepted
19 September
1994
Abstract While recent psychosocial stress has been shown to be associated with the initiation of both first and subsequent illness episodes in bipolar affective disorder, its relationship to completed suicide in bipolar disorder is not known. As a part of a nationwide psychological autopsy study, two populations representing all suicides in Finland in DSM-III-R bipolar disorder or unipolar major depression were comprehensively examined and compared. Recent life etents were retrospectively examined by interviewing next of kin using a 32-item Recent Life Change Questionnaire. Life event data was available on 25 bipolar and 56 unipolar cases. In about two-thirds of both bipolar (64% 1and unipolar (66%) victims, at least one life event was reported to have occurred during the last 3 months and in 4Yrt of both groups during the final week. The events of bipolar victims were more commonly classified as possibly dependent on their own behaviour (bipolars 88% vs. unipolars h3%, P= 0.004). Among bipolars, more males than females had had recent life events (males 86% vs. femaies 37%. P = 0.03). The majority of completed suicides in both bipolar and unipolar affective disorders seem to be associated with recent psychosocial stress; howe\cr. the stressors are commonly likely to be dependent on the victim’s behaviour.
1. Introduction
Adverse recent life events have been shown to be a risk factor for attempted and completed suicide (Paykel and Dowlatshahi, 1988; Heikkinen et al., 1993). In bipolar affective disorder, Iife events independent of patients’ behaviour seem to be temporally associated with the onset of first illnes4 episode (Dunner et al., 1979; Ambelas,
’ Corresponding
author.
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1979; Giassner and Haldipur, 1983: Bidzinska, 1984; Ambelas, 1987). Five out of eight controlled studies have shown an increase in independent life events before relapse to a subsequent episode (Hall et al., 1977; Kennedy et al., 1983; Chung et al., 1986; Joffe et al., 1989; Ellicott et al., 1990; Sclare and Creed, 1990; Hunt et al., 1992; McPherson et al., 1993) although the role of psychosocial stress seems to be less important in the latter stages of the illness (Post, 1992). However, the role of recent life events in completed suicides of persons suffering from bipolar affective disorder has not been investigated. reserved
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We have previously reported on a population representing all suicides in DSM-III-R bipolar disorder (bipolar I> in Finland over a 12-month period and compared this group with a representative population of major depressive suicides (Isometsa et al., 1994a). The aim of the present study was to examine recent life events among the bipolar suicides in comparison to unipolar cases.
2. Methods This study is part of the National Suicide Prevention Project in Finland (Lijnnqvist, 1988; Marttunen et al., 1991; Henriksson et al., 1993; Isometsl et al., 1994a,b). During the research phase of the project, all suicides committed in Finland between 1 April 1987 and 31 March 1988 (n = 1397) were carefully recorded and analysed using the psychological autopsy method (Litman et al., 1963; Shneidman, 1980). The definition of suicide was based on Finnish law for determining causes of death - in every case of violent, sudden or unexpected death, the possibility of suicide is assessed by police and medicolegal investigations involving autopsy and forensic examinations. For the 1Zmonth duration of the research phase of the project, this gathering of data was more detailed than usual. Data concerning victims classified as suicides in forensic examination were collected via comprehensive interviews of the relatives and attending health care personnel; from psychiatric, medical and social agency records and suicide notes (Marttunen et al., 1991; Henriksson et., 1993; Isometsa et al., 1994a,b). The interview forms used were planned for the project and the interviewers were mental health professionals trained in their use. Four types of interview were made. (1) Face-to-face interviews of family members were usually conducted in their homes, with informed consent obtained beforehand. The structured interview forms contained 234 items concerning the victim’s everyday life and behaviour, family factors, use of alcohol and other drugs, previous suicidality, help-seeking and recent life events. (2) Health care professionals who had attended the victim during the
previous 12 months were interviewed face to face with a structured form containing 113 items about the victim’s state of health, treatment in the health care system, psychosocial stressors and level of functioning. The interview included a cross-sectional symptom questionnaire. (3) The last contact with health care or social agency professionals was separately evaluated by interviewing the attending personnel either face-to-face or by telephone. (4) Additional unstructured interviews were made by telephone if needed. The mean number of interviewed persons per case was 2.6 (range = O-6) among bipolar and 2.9 (range = O8) among unipolar cases (Isometsl et al., 1994a,b). In addition, information was included from psychiatric, medical, social agency, police, forensic examination and other available records and from suicide notes. A multidisciplinary team discussed all the cases and a comprehensive case report was written on the basis of all information available (Marttunen et al., 1991; Henriksson et al., 1993; Isometsa et al., 1994a,b). The mental disorders of suicide victims in Finland have been examined in a recently published diagnostic study of a random sample of 229 (16.4%) of the total 1397 suicides in this period (Henriksson et al., 1993). In this study, 93% of suicide victims investigated were found to have suffered from a DSM-III-R axis I mental disorder; however, comorbid disorders were found very common as only 12% of the cases had one single axis I disorder with no comorbidity. Of the 229 victims in the diagnostic study, 71 (31%) received a diagnosis of current (unipolar) major depression (Henriksson et al., 1993). These 71 victims, comprehensively described and reported elsewhere (Isometsa et al., 1994b), comprise the unipolar comparison group of this study. The bipolar cases were collected from the total population of 1397 suicides by initially identifying suspected cases of bipolar disorder; the first author (E. Isometsa) reviewed the files of all 1397 suicide cases collecting all suspected cases with any symptoms, behaviour, medications, family history or illness patterns during their lifetime possibly related to a manic or hypomanic episode (n = 125) (Isometsa et al., 1994a). After that, the retrospective diagnostic evaluation of suicide vic-
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of Affectice Disorders 33 (1995) 99-106
tims according to DSM-III-R criteria, weighing and integrating all available evidence, took place in two phases and similarly in both the diagnostic
Table I Numbers of bipolar and unipolar suicide victims having recent life events of different event categories during final week or last 3 months ’ as reported by informant Category of life events
Final t%,eek Any lite event Somarlc illness Illness in family Death Separation Serious conflicts with family Substantial financial deterioration Job problems Unemployment Residence change Retirement Incarceration Other adverse event Marriage or engagement Substantial financial improvement Last .i months Any life event Somatic illness Illnesa in family Death Separation Serious conflicts with family Substantial financial deterioration Job problems Unemployment Residence change Retirement Incarceration Other adverse event Marriage or engagement Substantial financial improvement a Includes final h n = 34 due to ’ n = 55 due to ’ n = 54 due to
Numbers (%) of bipolar suicides (n = 25)
Numbers (%‘c) of unipolar suicides (n = 56)
10 (42%) b 3 (12%) 1(40/o) b 0 (0%) 0 (0%) 4 (16%)
23 (42%) ’ 9 (16%) 3 (5%) 2 (4%) 4 (7%) 9 (17%) d
2 (8%)
1(2%)
2 (8%) 1(4%) 2 (8%) 1(4%) 0 (0%) 0 (0%) 0 (0%) 0 (0%)
4 (7%) I(2%) 0 (0%) 2 (4%) 0 (0%) 0 (0%) c 0 (0%) 0 (0%)
16 (64%) 4 (16%) 1(4%) 0 (0%) 3 (12%) 9 (36%)
37 (66%) 15 (27%) 9 (16%) 3 (5%) 8 (14%) 11(20%)
5 (20%)
4 (7%)
6 (24%) 2 (8%) 4 (16%) 2 (8%) 0 (0%) 1(4%) 0 (0%) 1(40/c)
8 (14%) 2 (4%) 3 (5%) 2 (4%) 0 (0%) 2 (4%) 1(2%) 1(2%)
week. missing data in one case. missing data in one case. missing data in two cases.
c
101
study and among suspected bipolar victims. (1) Two pairs of psychiatrists independently made provisional diagnoses tested for reliability using the Kappa method (Fleiss, 1975). (2) All cases of diagnostic disagreement were reanalysed with a third psychiatrist to achieve consensus. The reliability of the method was good in all categories included here; e.g., 0.67 for bipolar disorder (95% confidence limits (CL) = 0.52-0.82), 0.74 for major depression (CL = 0.64-0.84) and 0.92 for alcohol dependence (CL = 0.87-0.97) (Henriksson et al., 1993; Isometsl et al., 1994b). Using this method, 31 cases of bipolar disorder (bipolar I) were identified among all suicide cases (Isometsti et al., 1994a). The population of bipolar suicide victims (n = 31) comprised 18 (58%) males and 13 (42%) females and the mean age was 48.1 years (SD = 14.4 years, range = 25-76 years); most suicides occurred during a major depressive episode (78% [22/28]) but in some cases also during a mixed state (11% [3/28]) or during or immediately after remission from psychotic mania (11% [3/281); in three cases, the psychiatric state of the victim at the time of death was not reliably known. The comparison group of major depressive suicide victims comprised 45 (63%) males and 26 (37%) females, mean age 50.0 years (SD = 16.6 years, range = 13-88 years). Comorbid diagnoses of psychoactive substance use disorders were common in both subgroups (bipolars 32% vs. unipolars 34%) as were personality disorders (bipolars 15% [4/27] vs. unipolars 34% [22/65]), physical diseases (bipolars 45% vs. unipolars 52%) or other forms of comorbidity. Overall, 71% of the bipolar and 85% of the unipolar victims had comorbid diagnoses of mental disorder or physical illness. In comparison, the bipolar victims were more often divorced or living alone and more were currently receiving psychiatric treatment (bipolars 74% vs. unipolars 45%). Among bipolar victims, the mean age of males was lower than that of females (males 43.4 years vs. females 54.6 years) and all cases of comorbid alcohol dependence were males (males 56% vs. females 0%) (Isomet& et al., 1994a,b). Recent life events preceding suicide were examined via a list of 33 structured questions on
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different aspects of adult life. The questionnaire was included in the interview of the next of kin and was performed for 25 (81%) cases of the bipolar disorder group and 62 (87%) of the comparison group of major depressives. Life event data for six cases in the unipolar group were excluded because the interviewer did not consider the informants’ responses sufficiently reliable. Thus, 25 bipolar and 56 unipolar victims were finally included in the study populations. The life event data concerning the comparison group of major depressive suicides has been partially reported in a previous publication (Isometsa et al., submitted) The life event questionnaire was developed for an epidemiological survey in Finland (Lehtinen et al., 1985). It was based on the Recent Life Change Questionnaire instrument by Rahe (Rahe, 19771, with some modifications from the list by Paykel et al. (Paykel et al., 1969). One questionnaire item (‘change in get-togethers with friends’) was excluded because of the ambiguity of the question and its symptom-like implication (Lehman, 1978). All 32 items included were classified on logical grounds into either (1) events independent of victim’s own behaviour or (2) events possibly dependent on victim’s own behaviour. The independent events included, e.g., death or severe illness of spouse or close relative, while the possibly dependent events included, e.g., separation, substantial financial deterioration or job problems. The included 32 items were further combined according to area of life into 14 categories, presented in Table 1. Under category ‘separation’ we included divorce, separation due to arguments and breakup of steady dating; under category ‘death’ death of spouse, another family member or close friend. The time frame covered by the life event questionnaire was 3 months; in addition, if an event was reported, the informant was asked whether it had occurred during the last week or not. The reported rates were compared with the expected rates, assuming random distribution of events (8/91 final week, 83/91 rest of the 3-month period). The informants were also asked whether they believed if any events covered by the questionnaire would explain the death of the victim and
whether they thought some other event (not mentioned in the questionnaire) might do so. The statistical methods included x2 tests with Yates’ correction, Fisher’s exact test and twosample t test, all two-tailed when appropriate. Furthermore, a multivariate analysis (multiple logistic regression equation fitted through a stepwise variable selection procedure) was performed using the SAS software (SAS Institute, 1990) to analyse factors possibly associated with reported life events among bipolar patients, including marital status, socioeconomic status, type of informant, time interval between suicide and interview, living alone, activity in working life and comorbid alcohol dependence.
3. Results The proportions of victims having at least one recent life event reported were similar in the two diagnostic groups (Table 1). Of the bipolar victims, 16 (64%) had had at least one life event during the 3 last months, final week included and 10 cases (42%) during the final week. The figures for unipolars were 37 (66%) and 23 cases (42%), respectively. No statistically significant differences between the bipolar and unipolar victims were found in the overall rates of events during the two time frames, nor in rates of specific events or item categories. Significant sex differences were found among bipolar victims. A higher proportion of males than females were reported to have experienced recent life events during the total 3-month period (males 12/14 [86%] vs. females 4/11 [37%]; Fisher’s exact test, P = 0.032). Probably due to small numbers, the difference in proportions did not reach significance for the final week (males 8/14 [57%] vs. females 2/10 [20%1, NS). Statistically significant differences were not found in any of the rates of specific events or item categories of events between the sexes but the mean number of events during the final week was significantly higher among males than females (males 1.21, SD = 1.53; females 0.18, SD = 0.40; t = 2.17, df = 23, P = 0.04).
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In both diagnostic groups, the reported events seemed to cluster in the final week compared with expected rates distributed randomly over the 3-month period. Among bipolar victims, 40% of the events were reported to have occurred during the final week (19 events final week, 29 events remaining period; expected rates 4.2 and 43.8, x2 = 10.8, df = 1, P = 0.001). Among unipolar victims, as many as 52% of the events reportedly occurred during the final week (43 final week, 40 remaining period; expected rates 7.3 and 75.7, x2 = 34.3, df = 1, P < 0.001). The reported clustering was significant in bipolar males, among whom 45% of events occurred during the final week (17 and 21 events, expected 3.3 and 34.7 events; xZ = 10.8, df = 1, P = O.OOl>, but not in bipolar females, among whom 20% reportedly occurred during the final week (2 and 8 events, expected rates 0.9 and 9.1, NS). The number of events for bipolar females was small, however. There were no major sex differences among unipolar victims. Most of the life events were of the possibly dependent type in both diagnostic groups, more so among bipolar victims (bipolar 88% [42/48] vs. unipolar 63% [52/83], x2 = 8.08, df = 1, P = 0.004 1. Among bipolar victims, the independent events seemed to cluster more in the final week than the possibly dependent ones (independent 5/6 [83%1 vs. dependent 14/42 [33%], Fisher’s exact test, two-tailed, P = 0.06). A similar difference was not found among unipolar victims. In multivariate stepwise logistic regression analysis of the bipolar victims, the most powerful factor associated with having life events during the final 3 months among bipolar victims was male sex; the odds ratio for having an event was 10.5 (95% CL = 1.51-72.8) for males. No other variable, including age or diagnosis of alcohol dependence, reached significance level for entry after sex was entered into the logistic model. In both diagnostic groups, about one-half (bipolar 12/23 [52%] and unipolar 25/53 [47%]) of the Interviewed informants believed that the events reported in the questionnaire explained the death of the victim. No new life events, in addition to those already reported in the ques-
I03
tionnaire, were identified from the answers to the question concerning other events possibly explaining the suicide.
4. Discussion For about two-thirds of both bipolar (64%) and unipolar (66%) suicide victims, the next of kin interviewed reported the occurrence of at least one recent life event during the final 3 months before suicide. As appears from the rates of the event categories in Table 1, almost all of the reported life events were adverse and stressful. The bipolar suicide victims were reported to have had mainly events possibly dependent on their own behaviour (88% of events) whereas the events reported by the next of kin of unipolar victims were more equally of both types (possibly, dependent in 63%). In both groups, the events seemed usually to occur while the victim was already symptomatic, rather than to initiate the final episode. Taken as reported. the data would also seem to suggest clustering of life events in the final week before suicide among both diagnostic groups which might speak for a triggering role for them. To our knowledge, the present study is the first to examine the role of recent life events specifically in suicides of persons suffering from bipolar affective disorder. Its major asset is the representativeness of the populations examined. Several methodological problems need to be addressed, however. The relatively small sample size, of bipolar victims in particular, may limit the validity of our findings. Although in studying completed suicides the victim cannot be personally interviewed, the use of close relatives as informants has been shown reliable in methodological studies of life events, particularly concerning severe events (Schless and Mendels, 1078; Brown and Harris, 1982; Parry and Shapiro, lY86). The time frame covered by the life event questionnaire was 3 months, shorter than in several other suicide studies and, therefore, biased towards underestimates (Paykel and Dowlatshahi, 1988; Heikkinen et al., 1993). In addition, events that had not occurred but were anticipated by the
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victim were not included in the questionnaire and are thus not reported although case reports available to us seemed to suggest that they could have been important. Furthermore, the hvo time periods are somewhat arbitrarily delimited and it remains unknown whether some other time periods would have been proven more valid. However, one controlled study addressing life events also during the final week found an excess of them among suicides, supporting the validity of examining very recent psychosocial stress (Hagnell 1980). The most important and Rorsman, methodological limitation of the present study, however, is having neither living bipolar nor living unipolar subjects as a control group. Some degree of recall bias is likely to have occurred in the timing of events, and attempts of the family members to explain the suicide in terms of adverse life experiences may have artificially increased the number of events reported to have occurred close to the act. Moreover, as some events probably represented worsening of long-term difficulties rather than being discrete sudden events, their exact timing is difficult. Furthermore, dichotomizing the events into two time periods may also have increased the number of events in the final week. Such factors are likely to have inflated the proportion of events in the final week. On the other hand, the proportion of all events reported to have occurred during the final week is high (40% among bipolars and 52% among unipolars) and the difference between observed and expected rates of events is statistically very significant. The tendency for difference (P = 0.06) found in clustering between dependent and independent events among bipolar victims is also unlikely to have been caused by such biases. The possibility that life events particularly during the final week may have a triggering role in suicides of both bipolar and unipolar patients cannot be excluded but it needs to be confirmed in controlled studies comparing victims with living control patients. The bipoiar and unipolar groups did not seem to differ in rates of recent life events in any of the specific categories investigated. As the vast majority of bipolar victims (79%) had suffered from a major depressive episode before suicide, the
33 (19%) 99-106
two groups were presumably clinically quite similar during the final weeks. Affective episodes, manic ones in particular, are known to have major impact on the family life and social networks of patients (Romans and McPherson, 1992; Cot-yell et al., 1993). The higher proportion of victims divorced and living alone in the bipolar group is likely to have been a consequence of the devastating effect of the illness process in social relationships. However, this seemed commonly to have occurred during the earlier illness episodes; at the time of the final depressive episode, the two groups differed little in categories of life events. Compared with the unselected total suicide population in which 80% of suicides were reported to have experienced an event during the last 3 months and 57% during the last week (Heikkinen et al., 19941, the association of suicides with recent life stress seems somewhat weaker in bipolar and unipolar affective disorders though still significant. The overall number of recent life events among bipolar suicide victims depends greatly on whether life events possibly dependent on the victims’ own behaviour are included; if not, the overall proportion of persons with recent life events is remarkably smaller (17%). However, this is partly due to the rather stringent classification of as possibly dependent all events that may have been caused by the victim, irrespective of true role of the victim in their causation. Studies of life events in bipolar disorder have not usually included dependent events. This is reasonable when examining causation of the illness but suicide is a different matter. There are arguments for the validity of examining dependent events among suicides. (1) Suicide is a multidetermined act and, although the mental disorder is generally considered a necessary condition for suicide, it is usually not sufficient alone. The failure of a methodologically sophisticated attempt to predict suicide among affective patients on the grounds of currently known risk factors (Goldstein et al., 1991) may suggest that other factors, such as adverse life events, also need to be examined. (2) Shame, guilt and hopelessness possibly related to or worsened by self-inflicted adverse life events are plausible psychological factors in suicides; so in
E. hornetsi et al. /Journal
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theory, dependent events could be related to an even higher suicide risk than independent events. (3) The consequences of an event, e.g., separation, are often important irrespective of whether the person in question caused it or not (Miller et al., 1986). Few of the events classified as possibly dependent were likely to have been intentional. We suggest that self-inflicted psychosocial stress should be taken into account when examining possible risk factors of suicide. Remarkably, more male bipolar suicide victims seemed to have had stressors than the females (86 vs. 37%, respectively). Although the males were on average younger and had markedly more comorbid alcoholism than the females, neither factor reached significance level for entry after sex was entered into the logistic model. A similar sex difference was not found among the comparison group of unipolars. The fact that the sex difference among bipolars consisted of both types of events may indicate that the bipolar male suicides were generally more related to psychosocial stress than those of the females. Further studies addressing sex differences in bipolar suicides are needed to confirm and explain these findings. In conclusion, about two-thirds of both bipolar and unipolar suicides were reported by informants to have faced adverse life events during their final 3 months. Bipolar cases were somewhat more commonly reported to have had stressors dependent on their own behaviour, rather than independent, compared with unipolar cases. Among bipolar suicide victims male suicides seemed to be more commonly associated with life events than those of females. An adverse life event during an illness episode may possibly increase the suicide risk of the subject, particularly for the following days and weeks. If confirmed in future studies, this may have important implications for the treatment and suicide prevention of affective patients.
Acknowledgements
The present study was supported from the Academy of Finland.
by a grant
1OS
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Journal
of Affective
Disorders
33 (19%) 99-106
Recent life events and completed suicide in bipolar affective disorder. A comparison with major depressive suicides Erkki IsometsS ‘t*, Martti Heikkinen a, Markus Henriksson Jouko tinnqvist a
‘vh,Hillevi Aro ‘,
” Department of Menial Health, National Public Health Institute, Mannerheimintie ’ Department Received
166, FIN-00300 Helsinki. Finland of Psychiatry, Helsinki Unicwsiry, Helsinki, Finland
5 July 1994; revised
19 September
1994: accepted
19 September
1994
Abstract While recent psychosocial stress has been shown to be associated with the initiation of both first and subsequent illness episodes in bipolar affective disorder, its relationship to completed suicide in bipolar disorder is not known. As a part of a nationwide psychological autopsy study, two populations representing all suicides in Finland in DSM-III-R bipolar disorder or unipolar major depression were comprehensively examined and compared. Recent life etents were retrospectively examined by interviewing next of kin using a 32-item Recent Life Change Questionnaire. Life event data was available on 25 bipolar and 56 unipolar cases. In about two-thirds of both bipolar (64% 1and unipolar (66%) victims, at least one life event was reported to have occurred during the last 3 months and in 4Yrt of both groups during the final week. The events of bipolar victims were more commonly classified as possibly dependent on their own behaviour (bipolars 88% vs. unipolars h3%, P= 0.004). Among bipolars, more males than females had had recent life events (males 86% vs. femaies 37%. P = 0.03). The majority of completed suicides in both bipolar and unipolar affective disorders seem to be associated with recent psychosocial stress; howe\cr. the stressors are commonly likely to be dependent on the victim’s behaviour.
1. Introduction
Adverse recent life events have been shown to be a risk factor for attempted and completed suicide (Paykel and Dowlatshahi, 1988; Heikkinen et al., 1993). In bipolar affective disorder, Iife events independent of patients’ behaviour seem to be temporally associated with the onset of first illnes4 episode (Dunner et al., 1979; Ambelas,
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1979; Giassner and Haldipur, 1983: Bidzinska, 1984; Ambelas, 1987). Five out of eight controlled studies have shown an increase in independent life events before relapse to a subsequent episode (Hall et al., 1977; Kennedy et al., 1983; Chung et al., 1986; Joffe et al., 1989; Ellicott et al., 1990; Sclare and Creed, 1990; Hunt et al., 1992; McPherson et al., 1993) although the role of psychosocial stress seems to be less important in the latter stages of the illness (Post, 1992). However, the role of recent life events in completed suicides of persons suffering from bipolar affective disorder has not been investigated. reserved
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We have previously reported on a population representing all suicides in DSM-III-R bipolar disorder (bipolar I> in Finland over a 12-month period and compared this group with a representative population of major depressive suicides (Isometsa et al., 1994a). The aim of the present study was to examine recent life events among the bipolar suicides in comparison to unipolar cases.
2. Methods This study is part of the National Suicide Prevention Project in Finland (Lijnnqvist, 1988; Marttunen et al., 1991; Henriksson et al., 1993; Isometsl et al., 1994a,b). During the research phase of the project, all suicides committed in Finland between 1 April 1987 and 31 March 1988 (n = 1397) were carefully recorded and analysed using the psychological autopsy method (Litman et al., 1963; Shneidman, 1980). The definition of suicide was based on Finnish law for determining causes of death - in every case of violent, sudden or unexpected death, the possibility of suicide is assessed by police and medicolegal investigations involving autopsy and forensic examinations. For the 1Zmonth duration of the research phase of the project, this gathering of data was more detailed than usual. Data concerning victims classified as suicides in forensic examination were collected via comprehensive interviews of the relatives and attending health care personnel; from psychiatric, medical and social agency records and suicide notes (Marttunen et al., 1991; Henriksson et., 1993; Isometsa et al., 1994a,b). The interview forms used were planned for the project and the interviewers were mental health professionals trained in their use. Four types of interview were made. (1) Face-to-face interviews of family members were usually conducted in their homes, with informed consent obtained beforehand. The structured interview forms contained 234 items concerning the victim’s everyday life and behaviour, family factors, use of alcohol and other drugs, previous suicidality, help-seeking and recent life events. (2) Health care professionals who had attended the victim during the
previous 12 months were interviewed face to face with a structured form containing 113 items about the victim’s state of health, treatment in the health care system, psychosocial stressors and level of functioning. The interview included a cross-sectional symptom questionnaire. (3) The last contact with health care or social agency professionals was separately evaluated by interviewing the attending personnel either face-to-face or by telephone. (4) Additional unstructured interviews were made by telephone if needed. The mean number of interviewed persons per case was 2.6 (range = O-6) among bipolar and 2.9 (range = O8) among unipolar cases (Isometsl et al., 1994a,b). In addition, information was included from psychiatric, medical, social agency, police, forensic examination and other available records and from suicide notes. A multidisciplinary team discussed all the cases and a comprehensive case report was written on the basis of all information available (Marttunen et al., 1991; Henriksson et al., 1993; Isometsa et al., 1994a,b). The mental disorders of suicide victims in Finland have been examined in a recently published diagnostic study of a random sample of 229 (16.4%) of the total 1397 suicides in this period (Henriksson et al., 1993). In this study, 93% of suicide victims investigated were found to have suffered from a DSM-III-R axis I mental disorder; however, comorbid disorders were found very common as only 12% of the cases had one single axis I disorder with no comorbidity. Of the 229 victims in the diagnostic study, 71 (31%) received a diagnosis of current (unipolar) major depression (Henriksson et al., 1993). These 71 victims, comprehensively described and reported elsewhere (Isometsa et al., 1994b), comprise the unipolar comparison group of this study. The bipolar cases were collected from the total population of 1397 suicides by initially identifying suspected cases of bipolar disorder; the first author (E. Isometsa) reviewed the files of all 1397 suicide cases collecting all suspected cases with any symptoms, behaviour, medications, family history or illness patterns during their lifetime possibly related to a manic or hypomanic episode (n = 125) (Isometsa et al., 1994a). After that, the retrospective diagnostic evaluation of suicide vic-
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tims according to DSM-III-R criteria, weighing and integrating all available evidence, took place in two phases and similarly in both the diagnostic
Table I Numbers of bipolar and unipolar suicide victims having recent life events of different event categories during final week or last 3 months ’ as reported by informant Category of life events
Final t%,eek Any lite event Somarlc illness Illness in family Death Separation Serious conflicts with family Substantial financial deterioration Job problems Unemployment Residence change Retirement Incarceration Other adverse event Marriage or engagement Substantial financial improvement Last .i months Any life event Somatic illness Illnesa in family Death Separation Serious conflicts with family Substantial financial deterioration Job problems Unemployment Residence change Retirement Incarceration Other adverse event Marriage or engagement Substantial financial improvement a Includes final h n = 34 due to ’ n = 55 due to ’ n = 54 due to
Numbers (%) of bipolar suicides (n = 25)
Numbers (%‘c) of unipolar suicides (n = 56)
10 (42%) b 3 (12%) 1(40/o) b 0 (0%) 0 (0%) 4 (16%)
23 (42%) ’ 9 (16%) 3 (5%) 2 (4%) 4 (7%) 9 (17%) d
2 (8%)
1(2%)
2 (8%) 1(4%) 2 (8%) 1(4%) 0 (0%) 0 (0%) 0 (0%) 0 (0%)
4 (7%) I(2%) 0 (0%) 2 (4%) 0 (0%) 0 (0%) c 0 (0%) 0 (0%)
16 (64%) 4 (16%) 1(4%) 0 (0%) 3 (12%) 9 (36%)
37 (66%) 15 (27%) 9 (16%) 3 (5%) 8 (14%) 11(20%)
5 (20%)
4 (7%)
6 (24%) 2 (8%) 4 (16%) 2 (8%) 0 (0%) 1(4%) 0 (0%) 1(40/c)
8 (14%) 2 (4%) 3 (5%) 2 (4%) 0 (0%) 2 (4%) 1(2%) 1(2%)
week. missing data in one case. missing data in one case. missing data in two cases.
c
101
study and among suspected bipolar victims. (1) Two pairs of psychiatrists independently made provisional diagnoses tested for reliability using the Kappa method (Fleiss, 1975). (2) All cases of diagnostic disagreement were reanalysed with a third psychiatrist to achieve consensus. The reliability of the method was good in all categories included here; e.g., 0.67 for bipolar disorder (95% confidence limits (CL) = 0.52-0.82), 0.74 for major depression (CL = 0.64-0.84) and 0.92 for alcohol dependence (CL = 0.87-0.97) (Henriksson et al., 1993; Isometsl et al., 1994b). Using this method, 31 cases of bipolar disorder (bipolar I) were identified among all suicide cases (Isometsti et al., 1994a). The population of bipolar suicide victims (n = 31) comprised 18 (58%) males and 13 (42%) females and the mean age was 48.1 years (SD = 14.4 years, range = 25-76 years); most suicides occurred during a major depressive episode (78% [22/28]) but in some cases also during a mixed state (11% [3/28]) or during or immediately after remission from psychotic mania (11% [3/281); in three cases, the psychiatric state of the victim at the time of death was not reliably known. The comparison group of major depressive suicide victims comprised 45 (63%) males and 26 (37%) females, mean age 50.0 years (SD = 16.6 years, range = 13-88 years). Comorbid diagnoses of psychoactive substance use disorders were common in both subgroups (bipolars 32% vs. unipolars 34%) as were personality disorders (bipolars 15% [4/27] vs. unipolars 34% [22/65]), physical diseases (bipolars 45% vs. unipolars 52%) or other forms of comorbidity. Overall, 71% of the bipolar and 85% of the unipolar victims had comorbid diagnoses of mental disorder or physical illness. In comparison, the bipolar victims were more often divorced or living alone and more were currently receiving psychiatric treatment (bipolars 74% vs. unipolars 45%). Among bipolar victims, the mean age of males was lower than that of females (males 43.4 years vs. females 54.6 years) and all cases of comorbid alcohol dependence were males (males 56% vs. females 0%) (Isomet& et al., 1994a,b). Recent life events preceding suicide were examined via a list of 33 structured questions on
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different aspects of adult life. The questionnaire was included in the interview of the next of kin and was performed for 25 (81%) cases of the bipolar disorder group and 62 (87%) of the comparison group of major depressives. Life event data for six cases in the unipolar group were excluded because the interviewer did not consider the informants’ responses sufficiently reliable. Thus, 25 bipolar and 56 unipolar victims were finally included in the study populations. The life event data concerning the comparison group of major depressive suicides has been partially reported in a previous publication (Isometsa et al., submitted) The life event questionnaire was developed for an epidemiological survey in Finland (Lehtinen et al., 1985). It was based on the Recent Life Change Questionnaire instrument by Rahe (Rahe, 19771, with some modifications from the list by Paykel et al. (Paykel et al., 1969). One questionnaire item (‘change in get-togethers with friends’) was excluded because of the ambiguity of the question and its symptom-like implication (Lehman, 1978). All 32 items included were classified on logical grounds into either (1) events independent of victim’s own behaviour or (2) events possibly dependent on victim’s own behaviour. The independent events included, e.g., death or severe illness of spouse or close relative, while the possibly dependent events included, e.g., separation, substantial financial deterioration or job problems. The included 32 items were further combined according to area of life into 14 categories, presented in Table 1. Under category ‘separation’ we included divorce, separation due to arguments and breakup of steady dating; under category ‘death’ death of spouse, another family member or close friend. The time frame covered by the life event questionnaire was 3 months; in addition, if an event was reported, the informant was asked whether it had occurred during the last week or not. The reported rates were compared with the expected rates, assuming random distribution of events (8/91 final week, 83/91 rest of the 3-month period). The informants were also asked whether they believed if any events covered by the questionnaire would explain the death of the victim and
whether they thought some other event (not mentioned in the questionnaire) might do so. The statistical methods included x2 tests with Yates’ correction, Fisher’s exact test and twosample t test, all two-tailed when appropriate. Furthermore, a multivariate analysis (multiple logistic regression equation fitted through a stepwise variable selection procedure) was performed using the SAS software (SAS Institute, 1990) to analyse factors possibly associated with reported life events among bipolar patients, including marital status, socioeconomic status, type of informant, time interval between suicide and interview, living alone, activity in working life and comorbid alcohol dependence.
3. Results The proportions of victims having at least one recent life event reported were similar in the two diagnostic groups (Table 1). Of the bipolar victims, 16 (64%) had had at least one life event during the 3 last months, final week included and 10 cases (42%) during the final week. The figures for unipolars were 37 (66%) and 23 cases (42%), respectively. No statistically significant differences between the bipolar and unipolar victims were found in the overall rates of events during the two time frames, nor in rates of specific events or item categories. Significant sex differences were found among bipolar victims. A higher proportion of males than females were reported to have experienced recent life events during the total 3-month period (males 12/14 [86%] vs. females 4/11 [37%]; Fisher’s exact test, P = 0.032). Probably due to small numbers, the difference in proportions did not reach significance for the final week (males 8/14 [57%] vs. females 2/10 [20%1, NS). Statistically significant differences were not found in any of the rates of specific events or item categories of events between the sexes but the mean number of events during the final week was significantly higher among males than females (males 1.21, SD = 1.53; females 0.18, SD = 0.40; t = 2.17, df = 23, P = 0.04).
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In both diagnostic groups, the reported events seemed to cluster in the final week compared with expected rates distributed randomly over the 3-month period. Among bipolar victims, 40% of the events were reported to have occurred during the final week (19 events final week, 29 events remaining period; expected rates 4.2 and 43.8, x2 = 10.8, df = 1, P = 0.001). Among unipolar victims, as many as 52% of the events reportedly occurred during the final week (43 final week, 40 remaining period; expected rates 7.3 and 75.7, x2 = 34.3, df = 1, P < 0.001). The reported clustering was significant in bipolar males, among whom 45% of events occurred during the final week (17 and 21 events, expected 3.3 and 34.7 events; xZ = 10.8, df = 1, P = O.OOl>, but not in bipolar females, among whom 20% reportedly occurred during the final week (2 and 8 events, expected rates 0.9 and 9.1, NS). The number of events for bipolar females was small, however. There were no major sex differences among unipolar victims. Most of the life events were of the possibly dependent type in both diagnostic groups, more so among bipolar victims (bipolar 88% [42/48] vs. unipolar 63% [52/83], x2 = 8.08, df = 1, P = 0.004 1. Among bipolar victims, the independent events seemed to cluster more in the final week than the possibly dependent ones (independent 5/6 [83%1 vs. dependent 14/42 [33%], Fisher’s exact test, two-tailed, P = 0.06). A similar difference was not found among unipolar victims. In multivariate stepwise logistic regression analysis of the bipolar victims, the most powerful factor associated with having life events during the final 3 months among bipolar victims was male sex; the odds ratio for having an event was 10.5 (95% CL = 1.51-72.8) for males. No other variable, including age or diagnosis of alcohol dependence, reached significance level for entry after sex was entered into the logistic model. In both diagnostic groups, about one-half (bipolar 12/23 [52%] and unipolar 25/53 [47%]) of the Interviewed informants believed that the events reported in the questionnaire explained the death of the victim. No new life events, in addition to those already reported in the ques-
I03
tionnaire, were identified from the answers to the question concerning other events possibly explaining the suicide.
4. Discussion For about two-thirds of both bipolar (64%) and unipolar (66%) suicide victims, the next of kin interviewed reported the occurrence of at least one recent life event during the final 3 months before suicide. As appears from the rates of the event categories in Table 1, almost all of the reported life events were adverse and stressful. The bipolar suicide victims were reported to have had mainly events possibly dependent on their own behaviour (88% of events) whereas the events reported by the next of kin of unipolar victims were more equally of both types (possibly, dependent in 63%). In both groups, the events seemed usually to occur while the victim was already symptomatic, rather than to initiate the final episode. Taken as reported. the data would also seem to suggest clustering of life events in the final week before suicide among both diagnostic groups which might speak for a triggering role for them. To our knowledge, the present study is the first to examine the role of recent life events specifically in suicides of persons suffering from bipolar affective disorder. Its major asset is the representativeness of the populations examined. Several methodological problems need to be addressed, however. The relatively small sample size, of bipolar victims in particular, may limit the validity of our findings. Although in studying completed suicides the victim cannot be personally interviewed, the use of close relatives as informants has been shown reliable in methodological studies of life events, particularly concerning severe events (Schless and Mendels, 1078; Brown and Harris, 1982; Parry and Shapiro, lY86). The time frame covered by the life event questionnaire was 3 months, shorter than in several other suicide studies and, therefore, biased towards underestimates (Paykel and Dowlatshahi, 1988; Heikkinen et al., 1993). In addition, events that had not occurred but were anticipated by the
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victim were not included in the questionnaire and are thus not reported although case reports available to us seemed to suggest that they could have been important. Furthermore, the hvo time periods are somewhat arbitrarily delimited and it remains unknown whether some other time periods would have been proven more valid. However, one controlled study addressing life events also during the final week found an excess of them among suicides, supporting the validity of examining very recent psychosocial stress (Hagnell 1980). The most important and Rorsman, methodological limitation of the present study, however, is having neither living bipolar nor living unipolar subjects as a control group. Some degree of recall bias is likely to have occurred in the timing of events, and attempts of the family members to explain the suicide in terms of adverse life experiences may have artificially increased the number of events reported to have occurred close to the act. Moreover, as some events probably represented worsening of long-term difficulties rather than being discrete sudden events, their exact timing is difficult. Furthermore, dichotomizing the events into two time periods may also have increased the number of events in the final week. Such factors are likely to have inflated the proportion of events in the final week. On the other hand, the proportion of all events reported to have occurred during the final week is high (40% among bipolars and 52% among unipolars) and the difference between observed and expected rates of events is statistically very significant. The tendency for difference (P = 0.06) found in clustering between dependent and independent events among bipolar victims is also unlikely to have been caused by such biases. The possibility that life events particularly during the final week may have a triggering role in suicides of both bipolar and unipolar patients cannot be excluded but it needs to be confirmed in controlled studies comparing victims with living control patients. The bipoiar and unipolar groups did not seem to differ in rates of recent life events in any of the specific categories investigated. As the vast majority of bipolar victims (79%) had suffered from a major depressive episode before suicide, the
33 (19%) 99-106
two groups were presumably clinically quite similar during the final weeks. Affective episodes, manic ones in particular, are known to have major impact on the family life and social networks of patients (Romans and McPherson, 1992; Cot-yell et al., 1993). The higher proportion of victims divorced and living alone in the bipolar group is likely to have been a consequence of the devastating effect of the illness process in social relationships. However, this seemed commonly to have occurred during the earlier illness episodes; at the time of the final depressive episode, the two groups differed little in categories of life events. Compared with the unselected total suicide population in which 80% of suicides were reported to have experienced an event during the last 3 months and 57% during the last week (Heikkinen et al., 19941, the association of suicides with recent life stress seems somewhat weaker in bipolar and unipolar affective disorders though still significant. The overall number of recent life events among bipolar suicide victims depends greatly on whether life events possibly dependent on the victims’ own behaviour are included; if not, the overall proportion of persons with recent life events is remarkably smaller (17%). However, this is partly due to the rather stringent classification of as possibly dependent all events that may have been caused by the victim, irrespective of true role of the victim in their causation. Studies of life events in bipolar disorder have not usually included dependent events. This is reasonable when examining causation of the illness but suicide is a different matter. There are arguments for the validity of examining dependent events among suicides. (1) Suicide is a multidetermined act and, although the mental disorder is generally considered a necessary condition for suicide, it is usually not sufficient alone. The failure of a methodologically sophisticated attempt to predict suicide among affective patients on the grounds of currently known risk factors (Goldstein et al., 1991) may suggest that other factors, such as adverse life events, also need to be examined. (2) Shame, guilt and hopelessness possibly related to or worsened by self-inflicted adverse life events are plausible psychological factors in suicides; so in
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theory, dependent events could be related to an even higher suicide risk than independent events. (3) The consequences of an event, e.g., separation, are often important irrespective of whether the person in question caused it or not (Miller et al., 1986). Few of the events classified as possibly dependent were likely to have been intentional. We suggest that self-inflicted psychosocial stress should be taken into account when examining possible risk factors of suicide. Remarkably, more male bipolar suicide victims seemed to have had stressors than the females (86 vs. 37%, respectively). Although the males were on average younger and had markedly more comorbid alcoholism than the females, neither factor reached significance level for entry after sex was entered into the logistic model. A similar sex difference was not found among the comparison group of unipolars. The fact that the sex difference among bipolars consisted of both types of events may indicate that the bipolar male suicides were generally more related to psychosocial stress than those of the females. Further studies addressing sex differences in bipolar suicides are needed to confirm and explain these findings. In conclusion, about two-thirds of both bipolar and unipolar suicides were reported by informants to have faced adverse life events during their final 3 months. Bipolar cases were somewhat more commonly reported to have had stressors dependent on their own behaviour, rather than independent, compared with unipolar cases. Among bipolar suicide victims male suicides seemed to be more commonly associated with life events than those of females. An adverse life event during an illness episode may possibly increase the suicide risk of the subject, particularly for the following days and weeks. If confirmed in future studies, this may have important implications for the treatment and suicide prevention of affective patients.
Acknowledgements
The present study was supported from the Academy of Finland.
by a grant
1OS
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