Bipolar pharmacotherapy and suicidal behavior. Part I: Lithium, divalproex and carbamazepine.

INTRODUCTION

The anti-suicidal benefit of lithium on suicidal behavior in bipolar disorder is well-established. Data are mixed on the effects of divalproex and carbamazepine.

METHODS

Retrospective chart review study of 405 veterans with bipolar disorder followed for a mean of 3 years, with month by month review of clinical progress notes, and systematic assessment of current pharmacotherapy and suicide completion, attempt or hospitalization for suicidality. Comparison of suicide event rates (events/100 patient years) between mood stabilizers and during-vs-after discontinuation of mood stabilizers, with linear regression analysis for influence of potential confounding variables, and robust bootstrap confirmation analysis.

RESULTS

No completed suicides occurred during or after discontinuation of monotherapy. Rates of non-lethal suicidal behavior were similar during lithium (2.49), divalproex (4.67) and carbamazepine (3.80) monotherapies. There was a sixteen fold greater, highly statistically significant non-lethal suicidal event rate after discontinuation compared with during mood stabilizer monotherapy (55.89 vs. 3.48 events/100 patient years; Chi2=13.95; df=1; p<0.0002). On compared with off treatment differences were similar for the three different agents.

LIMITATIONS

Treatments were uncontrolled in this naturalistic setting, and data were analyzed retrospectively.

CONCLUSIONS

Lithium and the anticonvulsants may show similar benefits in protecting bipolar patients from non-lethal suicidal behavior when careful analysis of clinical data is done to confirm medication adherence/non-adherence. Findings in this study were similar to those of a previous study that applied the same methodology in a private practice setting.