Although several randomized controlled trials (RCTs) have compared the
effectiveness, efficacy, and safety of antipsychotic monotherapy (APM) versus
placebo in patients with major depressive disorder (MDD), no meta-analysis has
examined this topic. We conducted a systematic literature search using MEDLINE
and Embase to identify relevant RCTs and performed a meta-analysis to compare
the following outcomes between APM and placebo: response and remission rates,
study discontinuation due to all causes, lack of efficacy, and adverse events,
changes in total scores on depression severity scales, and individual adverse
event rates. A total of 13 studies were identified, with 14 comparisons
involving 3,197 participants that met the eligibility criteria. There were
significant differences between APM and placebo in response and remission rates
and changes in the primary depression severity scale in favor of APM, and study
discontinuation due to adverse events and several individual adverse events in
favor of placebo. No significant difference was observed in discontinuation due
to all causes. APM could have antidepressant effects in the acute phase of MDD,
although clinicians should be aware of an increased risk of some adverse
events.