Positive Psychology Intervention Effects on Emotions and Well-Being in Depression: A Systematic Review and Meta-Analysis

Purpose: The current systematic review and meta-analysis evaluated the effectiveness of positive psychology intervention (PPI) on emotional well-being and depression in adults. The objective was to assess whether PPI improves happiness, life satisfaction, and psychological well-being, and whether it serves as a viable alternative to standard or no treatment in managing depression. Method: A systematic search was conducted in five electronic databases. Seventeen randomized controlled trials involving 2,579 participants were included. Standardized mean difference (SMD) or mean difference (MD) with 95% confidence intervals (CIs) were calculated. Results: PPI significantly improved happiness (SMD = 0.25; 95% CI [0.06, 0.43]), positive affect (MD = 2.41; 95% CI [0.27, 4.54]), life satisfaction (MD = 2.18; 95% CI [0.81, 3.54]), and environmental mastery (SMD = 0.28; 95% CI [0.02, 0.54]). Depression scores showed no significant change (SMD = −0.27; 95% CI [−0.61, 0.08]). Conclusion: PPI enhances positive mental health indicators, including happiness, positive affect, and well-being, but has limited effect on depression severity. PPI may serve as a complementary tool alongside standard treatment.