Objective: This meta-analysis reviewed data on the efficacy and effectiveness of second-generation antidepressants for preventing major depression relapse and recurrence during continuation and maintenance phases of treatment, respectively. Methods: MEDLINE, EMBASE, and PsycINFO, the Cochrane Library, and International Pharmaceutical Abstracts were searched for the period of January 1980 through April 2007 for reviews, randomized controlled trials, meta-analyses, and observational studies on the topic. Two persons independently reviewed abstracts and full-text articles using a structured data abstraction form to ensure consistency in appraisal and data extraction. Results: Four comparative trials and 23 placebo-controlled trials that addressed relapse or recurrence prevention were included. Results of comparative trials have not demonstrated statistically significant differences between duloxetine and paroxetine, fluoxetine and sertraline, fluvoxamine and sertraline, and trazodone and venlafaxine. Pooled data for the class of second-generation antidepressants compared with placebo suggested a relatively large effect size that persists over time. For preventing both relapse and recurrence, the number of patients needed to treat is five (95% confidence interval of 4 to 6). Differences in the length of open-label treatment before randomization, drug type, and trial duration did not affect pooled estimates of relapse rates. Across all trials, 7% of patients randomly assigned to receive active treatment and 5% of patients randomly assigned to receive a placebo discontinued treatment because of adverse events. Conclusions: This review demonstrates the overall benefits of continuation- and maintenance-phase treatment of major depression with second-generation antidepressants and emphasizes the need for additional studies of comparative differences among drugs.