Lithium, anticonvulsants and suicidal behavior in bipolar disorder.

BACKGROUND: Lithium has been found to be effective in reducing suicide rates during long term treatment of patients with bipolar disorders. Data on the efficacy of anticonvulsant mood stabilizers in reducing suicide risk are sparse.

METHOD: Charts of 140 bipolar patients treated continuously for a minimum of 6 months during a 23-year period of private practice by the senior author were extracted from nearly 4000 patient records. Data extracted from the charts were incidence of completed suicide, number of suicide attempts, and number of hospitalizations for suicidal ideation or behavior per 100 patient-years of either 'on' or 'off' lithium or anticonvulsant mood stabilizer monotherapy.

RESULTS: Only one completed suicide (during a period off of lithium) occurred in the patients studied. Incidence of non-lethal suicidal behavior was not different during treatment with lithium, compared with anticonvulsants. Being on a mood stabilizer significantly protected against suicidal behavior. The relative protective effect was more modest than in reports from other treatment settings.

LIMITATIONS: This was a retrospective chart review study of naturalistically treated patients.

CONCLUSIONS: Treatment of patients with bipolar disorder with either lithium or anticonvulsant mood stabilizers was associated with reduced risk of suicidal behavior. This study did not find evidence for a difference in the protective effect of the two types of mood stabilizing medications against non-lethal suicidal behavior in the naturalistic setting of private practice.