The best possible self task has direct effects on expectancies and mood, and an indirect effect on anxiety symptom severity

Official URL: https://dx.doi.org/10.1037/emo0001481

The Best Possible Self task (BPS) is one of the best studied positive psychology interventions, and robustly improves optimism (expectancies) and mood. However, few studies have examined whether the task primarily affects expectancies, which then improve mood, or whether it primarily improves mood, which then affects expectancies. From 2023 to 2024, we conducted a well-powered, preregistered randomized controlled trial, with 240 unselected students at a private university in Istanbul. Mediation analyses showed that, at posttest, the BPS had large direct effects on positive expectancies, negative expectancies, and positive mood; and a small indirect effect on negative mood via negative expectancies. At 1-week follow-up (N = 202), the BPS had a small-to-medium effect on positive expectancies, which mediated a similar-sized effect on anxious symptom severity. These results indicate that the BPS affects both expectancies and mood, but its effects on expectancies are longer lasting, and can lead to improvements in anxiety symptoms. More research is needed into the mechanisms of the BPS’s effects in other populations, and especially into its possible benefits for people with anxiety.