Background: Several long-term double-blind placebo controlled trials have shown prophylactic antidepressant therapy in unipolar depression. The goal of this work was to conduct a meta-analysis that would incorporate the most recent trials and evaluate their overall level of efficacy and relapse prevention over time.
Methods: We performed a comprehensive literature search. The extracted data from selected studies were used to construct a regression model and evaluate the effect of treatment, time on medication, severity of illness, age, gender, and number of previous episodes.
Results: Across 11 maintenance treatment studies, the relapse rate was significantly different at 1 year for active drug (23%) versus placebo (51%). In addition, time on medication significantly affected the relapse rate.
Conclusion: Prophylactic antidepressant drug therapy appears efficacious in preventing future relapses across a range of illness severity as well as age. More studies are needed to explore the effects of various acute antidepressant strategies and the direct influence of treatment resistance on relapse outcomes.