Inducing positive affect and positive future expectations using the best-possible-self intervention: A systematic review and meta-analysis

The best-possible-self intervention has been shown to effectively increase positive affect and optimism. Differences in timing and conceptualization of outcome assessments, however, complicate interpretations regarding the practical significance of these effects. To address this issue, we conducted a systematic literature search and included 34 randomized controlled trials into several meta-analyses. We coded the exact time of measurement and how outcomes were assessed. Results reveal small overall effects on positive affect (Hedge’s g = 0.28, 95% CI [0.16, 0.41]) and optimism (g = 0.21, 95% CI [0.04, 0.38]). Effects on positive affect were strongest among studies that assessed momentary affect immediately after the intervention, whereas effects on optimism were only significant if conceptualized as positive future expectations rather than a general orientation in life. Descriptive results indicate no substantial follow-up effects. Thus, the best-possible-self intervention might be thought of as a mood/expectation induction procedure. Further development may lead to sustained effects.