The rapid suicide protection of mood stabilizers on patients with bipolar disorder: A nationwide observational cohort study in Taiwan

Background The suicide rate is high among bipolar disorder (BD) patients. Previous studies have focused on the anti-suicidal effect of long-term treatment with mood stabilizers but less on the immediate preventive effects of interventions. The aim of the study was to evaluate the short-term and immediate anti-suicidal effects of mood stabilizers on recent-onset BD patients. Methods The National Health Insurance Database (NHID) of Taiwan was used to perform a nationwide cohort observation study of suicide behaviors in bipolar disorder. All the recent-onset BD patients (ICD-9-CM code 296 except 296.2 and 296.3) diagnosed between 2000-2005 were collected (n=5091) and followed through 2009. The primary endpoint was the presence of a suicide code or the end of observation; exposure to mood stabilizers in the final month of observation was the independent variable. Results The hazard ratios (HRs) of suicide-related events, completed suicide, and all-cause mortality were significantly lower for those treated with lithium, divalproex, or carbamazepine compared with no use in the last month (HRs of suicide-related events were 0.10, 0.14 and 0.10, respectively, and all-cause mortality HRs were 0.03; P<0.0001); there was no significant difference in HR between the mood stabilizers. Limitations The NIHD does not provide information on the severity, mood status, or treatment adherence of BD patients. Neither substance-related disorder nor personality disorder were included in the analysis. We focused on the effect of the final prescription time period, not the long-term protective effect. Conclusions The immediate recent use of any mood stabilizer significantly lowers the rate of death, suicide, or suicidal behavior in BD.