Background: The benefits of peer support interventions (PSIs) for individuals with mental illness are not well known. The aim of this systematic review and meta-analysis was to assess the effectiveness of PSIs for individuals with mental illness for clinical, personal, and functional recovery outcomes.
Methods: Searches were conducted in PubMed, Embase, and PsycINFO (December 18, 2020). Included were randomized controlled trials (RCTs) comparing peer-delivered PSIs to control conditions. The quality of records was assessed using the Cochrane Collaboration Risk of Bias tool. Data were pooled for each outcome, using random-effects models.
Results: After screening 3455 records, 30 RCTs were included in the systematic review and 28 were meta-analyzed (4152 individuals). Compared to control conditions, peer support was associated with small but significant post-test effect sizes for clinical recovery, g = 0.19, 95% CI (0.11-0.27), I2 = 10%, 95% CI (0-44), and personal recovery, g = 0.15, 95% CI (0.04-0.27), I2 = 43%, 95% CI (1-67), but not for functional recovery, g = 0.08, 95% CI (-0.02 to 0.18), I2 = 36%, 95% CI (0-61). Our findings should be considered with caution due to the modest quality of the included studies.
Conclusions: PSIs may be effective for the clinical and personal recovery of mental illness. Effects are modest, though consistent, suggesting potential efficacy for PSI across a wide range of mental disorders and intervention types.
Keywords: Clinical recovery; depression; functional recovery; mental illness; meta-analysis; peer support interventions; personal recovery; serious mental illness; systematic review.