Antipsychotic adjunctive therapy to mood stabilizers and 1-year rehospitalization rates in bipolar disorder: A cohort study.

OBJECTIVES: Antipsychotic adjunctive therapy to mood stabilizers (MSs) may improve relapse prevention; however, only a few naturalistic studies, reflecting more generalizable bipolar disorder (BD) samples, support this notion. We compared the 1-year rehospitalization rates of manic patients with bipolar I disorder (BD-I) who were discharged with MS (lithium or valproate) monotherapy or with adjunctive atypical or typical antipsychotic therapy.

METHODS: A total of 201 patients with BD-I who were hospitalized with manic episodes between 2005 and 2013 were retrospectively followed for 1-year rehospitalization rates according to treatment at discharge: MS monotherapy, MS with atypical antipsychotics, and MS with typical antipsychotics. Additionally, time to rehospitalization during the 1-year period after discharge was compared between treatment groups. Multivariable survival analyses adjusted for covariates known to influence rehospitalization were conducted.

RESULTS: Rehospitalization rates within 1 year were significantly lower in the MS with atypical antipsychotics group (6.3%) compared to the MS monotherapy group (24.3%, P=.008) and to the MS with typical antipsychotics group (20.6%, P=.02). Time to rehospitalization was significantly longer for the MS with atypical antipsychotics group (345.5 days) compared to the MS monotherapy group (315.1 days, P=.006) and to the MS with typical antipsychotics group (334.1 days, P=.02). The MS with atypical antipsychotics group had a significantly reduced adjusted risk of rehospitalization (hazard ratio=0.17, 95% confidence interval: 0.05-0.61, P=.007) compared to the MS monotherapy group.

CONCLUSIONS: Atypical antipsychotic adjunctive therapy to MSs may be more effective than MS monotherapy in preventing rehospitalization during the 1-year period after a BD manic episode.