Bipolar patients with suicidal behavior: toward the identification of a clinical subgroup.

BACKGROUND: Suicide is the most severe and frequent complication of bipolar disorder, but little is known about the clinical characteristics of bipolar patients at risk of suicide. The purpose of this study was to identify those characteristics.
METHOD: We studied 307 prospectively recruited DSM-IV-diagnosed bipolar I or II patients from November 1994 through October 2001. Semi-structured diagnostic interviews (the Diagnostic Interview for Genetic Studies and the Family Interview for Genetic Studies) were used to determine the diagnosis of bipolar disorder and its lifetime description, lifetime comorbid Axis I disorder diagnoses, familial history of psychiatric disorders and demographic characteristics.
RESULTS: One hundred twenty-nine bipolar patients (42%) had made at least 1 suicide attempt in their life. Lifetime history of suicidal behavior was associated with history of suicidal behavior in first-degree relatives but not with a familial history of mood disorder. Early age at onset of mood disorder, total number of previous depressive episodes, alcohol and tobacco use, social phobia, antidepressant-induced mania, and personal history of head injury were associated with suicidal behavior. No association was observed with gender or diagnosis of bipolar I or II disorder. Social phobias, tobacco use, and personal history of head injury were no longer associated with suicidal behavior in the multivariate analysis.
CONCLUSION: Bipolar patients with early age at bipolar disorder onset, high number of depressive episodes, personal history of antidepressant-induced mania, comorbid alcohol abuse, and suicidal behavior constitute a clinical subgroup at risk of suicidal behavior. This information, as well as familial history of suicide behavior, should improve suicide risk assessment in bipolar patients.