Effect of symptom severity on efficacy and safety of aripiprazole adjunctive to antidepressant monotherapy in major depressive disorder: a pooled analysis.

BACKGROUND: There is a paucity of evidence for outcome predictors in patients with major depressive disorder (MDD) not responding to initial antidepressant therapy (ADT). This post-hoc analysis evaluated whether MDD severity affects response to adjunctive aripiprazole.

METHODS: Data from 3 randomized, double-blind, placebo-controlled trials of adjunctive aripiprazole in adults with MDD and inadequate response to 1 to 3 ADT trials were pooled and stratified based on Montgomery-Åsberg Depression Rating Scale (MADRS) total score (mild, ≤24; moderate, 25-30; severe, ≥31). Treatment differences in change in MADRS total score and rates of response (≥50% MADRS improvement) and remission (response with MADRS total score ≤10) were analyzed at endpoint. Adverse events were assessed within each subgroup.

RESULTS: Aripiprazole produced greater improvement than placebo in the MADRS total score regardless of MDD severity at baseline (between-treatment difference [95% CI]: mild, -2.5 [-4.0 to -1.1]; moderate, -3.2 [-4.9 to -1.6]; severe, -4.5 [-6.8 to -2.2]). Compared with placebo, adjunctive aripiprazole increased the likelihood of response in all subgroups (risk ratio [95% CI]: mild, 1.50 [1.15, 1.95]; moderate, 1.51 [1.09, 2.11]; severe, 1.95 [1.23, 3.10]). Common treatment-emergent adverse events included akathisia and restlessness.

LIMITATIONS: The original studies were not designed to assess the efficacy of adjunctive aripiprazole by baseline severity, and this post-hoc analysis was not powered to evaluate differences in severity subgroups.

CONCLUSIONS: In patients who failed to respond to initial ADT, adjunctive aripiprazole was more effective than placebo in mild, moderate, and severe MDD strata.

CLINICAL TRIAL REGISTRATION: ClinicalTrial.gov: NCT00095823, NCT00105196, and NCT00095758.