An early intervention to promote well-being and flourishing and reduce anxiety and depression: A randomized controlled trial

Background: There is growing evidence that fostering mental well-being and flourishing might effectively prevent mental disorders. In this study, we examined whether a 9-week comprehensive positive self-help intervention with email support (TL-E) was effective in enhancing well-being and flourishing and decreasing anxiety and depressive symptoms in a non-clinical sample. Methods: A total of 275 participants with low or moderate well-being (mean age = 48 years, 86% female) were randomly assigned to a TL-E (n = 137) or wait-list control group (WL; n = 138). Participants completed online self-reporting questionnaires at baseline and at 3, 6 and 12 months. Results: Repeated measure analyses revealed significant more improvement on mental well-being (F = 42.00, p <= 0.001, d = 0.66, 95% CI = 0.42-0.90), anxiety (F = 21.65, p <= 0.001, d = 0.63, 95% CI = 0.39-0.87) and depression (F = 13.62, p <= 0.001, d = 0.43, 95% CI = 0.19-0.67) in the TL-E group versus the WL group. The proportion of flourishing in the TL-E group increased from 7 to 30% after 3 months (NNT = 5.46) and to 34% after 6 months (NNT = 5.25). All within group effects were maintained up to 12 months. We found no meaningful dose-response relationship for adherence, nor a clear moderator pattern. Limitations: It is unknown whether results were influenced by the email support that accompanied the self-help intervention since TL-E was only compared to a wait-list condition. The generalizability of the findings is limited by the self-selected sample of mainly higher-educated women. Conclusion: A guided positive self-help intervention might be considered as a new mental health promotion strategy because it has the potential to improve well-being up to the status of flourishing mental health, and to decrease anxiety and depressive symptomatology.