Efficacy of aripiprazole versus placebo as adjuncts to lithium or valproate in relapse prevention of manic or mixed episodes in bipolar I patients stratified by index manic or mixed episode

BackgroundDifferences in response to treatment have been observed for bipolar disorder (BPD) patients with manic or mixed episodes. This post-hoc analysis examined the maintenance effect of aripiprazole in combination with lithium or valproate in subpopulations of patients entering a relapse prevention study with either manic or mixed bipolar episodes.MethodsA long-term relapse prevention study of BPD patients with manic or mixed episodes included a single-blind stabilization phase, in which patients were stabilized with single-blind aripiprazole plus lithium or valproate (maintaining stability for 12 weeks), and a double-blind relapse assessment phase, where patients were randomized to aripiprazole or placebo plus lithium or valproate for up to 52 weeks. Lithium and valproate groups were pooled.ResultsThe time to relapse of any mood episode was longer in the adjunctive aripiprazole group versus the lithium/valproate monotherapy group for the manic (p<0.01) but not mixed population (p=0.59). The LOCF analysis indicated a significantly greater reduction in YMRS total score from baseline with continued aripiprazole versus placebo at 52 weeks in both manic (treatment difference=−3.32, p<0.01) and mixed episode populations (treatment difference=−2.56, p=0.02). Overall, adverse event profiles were similar between the populations.LimitationThe lithium and valproate subgroups were combined.ConclusionsThe continuation of aripiprazole in stabilized BPD patients treated with lithium or valproate increased the time to relapse of any mood episode for manic but not mixed patients; both groups achieved greater stability in YMRS total score with adjunctive aripiprazole. Thus, adjunctive aripiprazole may be more appropriate for stabilized patients with manic episodes.