Adjunctive antidepressants in bipolar depression: A cohort study of six- and twelve-months rehospitalization rates

Although antidepressants (ADs) are widely used in bipolar depression, there is weak evidence for their effectiveness and safety in this condition. Furthermore, there is a paucity of studies on the risk-benefit ratio of AD maintenance treatment in bipolar disorder (BD). We compared rehospitalization rates of patients with BD-I depressive episode who were discharged with mood stabilizers (MSs) and/or atypical antipsychotics (AAPs) with or without adjunctive AD. Ninety-eight patients with BD-I who were hospitalized with a depressive episode between 2005 and 2013 were retrospectively followed for 6-months and 1-year rehospitalization rates, as well as time to rehospitalization, according to treatment at discharge: MSs and/or AAPs with or without AD. Multivariable survival models adjusted for covariates known to influence rehospitalization were conducted. Six-months and 1-year rehospitalization rates were significantly lower in the adjunctive-AD treatment group compared to the no-AD group (9.2% vs. 36.4%, P = .001, power = 0.87 and 12.3% vs. 42.4%, P = .001, power = 0.89, respectively). Time to rehospitalization within 6-months and 1-year was significantly longer in the adjunctive-AD treatment group (169.9 vs 141 days, P = .001 and 335.6 vs 252.3 days, P = .001, respectively). Adjunctive-AD treatment at discharge reduced significantly the adjusted risk of rehospitalization within 6-months (HR = 0.081, 95% CI: 0.016-0.412, P = 0.002) and 1-year (HR = 0.149, 95% CI: 0.041-0.536, P = 0.004). Moreover, adjunctive-AD treatment did not increase rehospitalization rates of manic episode. In conclusion, adjunctive-AD therapy to MS/AAP at discharge from BD-I depressive episode hospitalization is associated with a lower rate of and a longer time to rehospitalization during a 1-year follow up period.