Lithium is associated with decrease in all-cause and suicide mortality in high-risk bipolar patients: A nationwide registry-based prospective cohort study.

BACKGROUND

Mortality rates, in particular due to suicide, are especially high in bipolar patients. This nationwide, registry-based study analyses the associations of medication use with hospitalization due to attempted suicides, deaths from suicide, and overall mortality across different psychotropic agents in bipolar patients.

METHOD

Altogether 826 bipolar patients hospitalized in Finland between 1996-2003 because of a suicide attempt were followed-up for a mean of 3.5 years. The relative risk of suicide attempts leading to hospitalization, completed suicide, and overall mortality during lithium vs. no-lithium, antipsychotic vs. no-antipsychotic, valproic acid vs. no-valproic acid, antidepressant vs. no-antidepressant and benzodiazepine vs. no-benzodiazepine treatment was measured.

RESULTS

The use of valproic acid (RR=1.53, 95% CI: 1.26-1.85, p<0.001), antidepressants (RR=1.49, 95% CI: 1.23-1.8, p<0.001) and benzodiazepines (RR=1.49, 95% CI: 1.23-1.80, p<0.001) was associated with increased risk of attempted suicide. Lithium was associated with a (non-significantly) lower risk of suicide attempts, and with significantly decreased suicide mortality in univariate (RR=0.39, 95% CI: 0.17-0.93, p=0.03), Cox (HR=0.37, 95% CI: 0.16-0.88, p=0.02) and marginal structural models (HR=0.31, 95% CI: 0.12-0.79, p=0.02). Moreover, lithium was related to decreased all-cause mortality by 49% (marginal structural models).

LIMITATIONS

Only high-risk bipolar patients hospitalized after a suicide attempt were studied. Diagnosis was not based on standardized diagnostic interviews; treatment regimens were uncontrolled.

CONCLUSIONS

Maintenance therapy with lithium, but not with other medications, is linked to decreased suicide and all-cause mortality in high-risk bipolar patients. Lithium should be considered for suicide prevention in high-risk bipolar patients.