The simultaneous impact of interventions on optimism and depression: A meta-analysis

The positive psychology approach to mental-health-related interventions suggests that a dual focus on positive and problematic characteristics is beneficial and that positive and negative characteristics interact. The present study explored the link between optimism and depression outcomes in intervention studies that assessed both optimism and depression outcomes. A meta-analysis examined effect sizes for depression and optimism and links between depression and optimism outcomes. Eighteen studies with a total of 2153 participants were included. Across studies the weighted effect sizes for the impact of interventions on both depression (g = 0.46) and optimism (g = 0.38) were significant. Optimism and depression outcomes were associated with one another (r(17) = 0.58). Meta-regression analyses also indicated linkages between the two outcomes in that the optimism effect sizes moderated depression effect sizes and depression effect sizes moderated optimism effect sizes. The results of the study lend support to a dual focus on positive and problematic characteristics.