Suicide attempts in veterans with bipolar disorder during treatment with lithium, divalproex, and atypical antipsychotics

Abstract

Suicide attempt rates were assessed in 1306 subjects in this 6 year retrospective study of Bipolar disorder. Participants were Veterans from 5 different Veterans Administration Hospitals who met criteria for bipolar type 1 or 2 and who had at least one prescription for lithium or divalproex or both during the study period. This study focused on the impact of atypical antipsychotics on the suicide attempt rate when used in addition to or in place of lithium or divalproex. Medication exposure was calculated using computerized pharmacy records. Suicide attempts were established through chart review including emergency room records, inpatient records, and outpatient records. There were a total of 117 suicide attempts and 2 suicide completions during the study period. Most attempts (59%) occurred when patients were on no medications. Nearly 90% of subjects spent an average of 45 months during the 6 year period on none of the aforementioned medications. The lowest percentage of suicide attempts (15%) occurred while on lithium, 21% while on divalproex and 24% while on atypical antipsychotics. When total months of exposure were taken into account, the lowest attempt rate occurred on lithium plus divalproex (6.3 attempts per 10,000 months of exposure), followed by divalproex alone (7.0 attempts/10,000 months of exposure), and lithium alone (7.7 attempts per 10,000 months of exposure). Patients on atypical antipsychotics alone had an attempt rate of 26.1 attempts per 10,000 months of exposure. In this study, lithium and divalproex provided protection against suicide attempts. Results need to be replicated in future prospective studies and clearly strategies for improving medication compliance among veterans are warranted.

Figure 1. Suicide Attempts by medication ever prescribed

Figure 2. Suicide Attempts for Combinations of Medications