Completed suicides and suicide attempts in which a person truly intends to die occur most often in persons suffering from major depression. Does stress also play a role in suicidal behaviors? That question was recently investigated by Maria Oquendo and her colleagues at Columbia University.
The Oquendo study examined the influence of life events and major depressive episodes on suicidal behavior over a 2-year period in persons diagnosed with depression at the time they were enrolled in the study. About 27% of study participants also had a diagnosis of borderline personality disorder, a condition characterized by long-standing erratic emotional dysregulation, impulsivity, and chaotic interpersonal relationships. For purposes of the study, suicidal behavior was defined as a "self-destructive act with some attempt to end one's life."
Participants were assessed at pre-determined intervals for up to two years, and the presence of depressive symptoms and suicidal behaviors were documented. Major life events were documented using a well-accepted research instrument designed to assess a variety of domains, including health, work, home and family, personal and social, and financial. This instrument evaluated both positive events, like a promotion, and negative events, like the death of a parent, and assigned various weights to each event to calculate an overall “life event score.” Major life events were found to occur in about a third of the months during the follow-up period. Depressive symptoms that fulfilled criteria for a major depressive episode were present about 70% of the time during the same period.
Approximately 10% of participants reported suicidal behaviors over the course of the study. A higher percentage of people with borderline personality disorder (18%) exhibited suicidal behaviors than those without this disorder (7%). Many of the people with suicidal behaviors had also attempted suicide prior to enrollment. Three participants died as a result of suicide during the course of the study.
The most powerful predictor of suicidal behavior was the concurrent presence of a major depressive episode. This was true both for those with and without borderline personality disorder. When considering the entire sample of individuals, life event scores did not correlate with suicidal behavior. However, in those individuals with depression in the absence of borderline personality disorder, health-related and work-related life events were time-linked to suicidal behaviors. Interestingly, this effect was not observed in persons who had both depression and borderline personality disorder. Although persons with borderline personality disorder had 2 to 3 times as many suicidal behaviors during follow-up as the group without borderline personality disorder, these suicidal behaviors were not associated with major life events. This was true even when the analysis was restricted to negative events. If anything, the occurrence of major life events was associated with fewer suicidal behaviors in participants with borderline personality disorder. The investigators acknowledge that this result is counterintuitive, and they indicate that this work will need to be replicated by others.
A major take home lesson from this study is that the presence of major depression is the primary predictor of suicidal behavior. Life events may modestly influence the risk in depressed patients without borderline personality disorder, but the presence of a current major depression is a far stronger predictor of suicidal behaviors than the presence of stressors. In order to decrease the risk of suicide, it is imperative to recognize and treat the major depression. To do otherwise can be a lethal mistake.
This article was written by Eugene Rubin MD, PhD and Charles Zorumski MD.