Brief self-affirmation intervention for adults with psoriasis for reducing anxiety and depression and boosting well-being: Evidence from a randomized controlled trial

Background There are relatively few studies to address mental health implications of self-affirming, especially across groups experiencing a chronic health condition. In this study, short- and longer-term effects of a brief self-affirmation intervention framed in terms of implementation intentions (if-then plans with self-affirming cognitions; S-AII) were evaluated against an active control group (non-affirming implementation intentions; N-AII), matched to the target condition, and mere goal intention condition (a non-active control) in adults with psoriasis. The three pre-registered primary outcomes captured depression, anxiety, and well-being. Methods Adults with psoriasis (N = 175; M-age = 36.53, s.d. = 11.52) were randomized into S-AII, N-AII, or control. Participants' mental health outcomes were assessed prior to randomization (at baseline), at week 2 (post-intervention), and at a 1-month follow-up. Results Linear mixed models were used and results were reported on the intention-to-treat principle. Analyses revealed that S-AII exerted significantly more improvement in the course of well-being (ds > 0.25), depressive symptoms (ds > -0.40), and anxiety (ds > -0.45) than the N-AII and control group at 2-week post-intervention. Though the differences between groups faded at 1-month follow-up, the within-group changes over time for S-AII in all mental health outcomes remained significant. Conclusions Brief and low-intensity S-AII intervention exerted in the short-term a considerable impact on mental health outcomes. The S-AII shows promising results as a relevant public mental health strategy for enhancing well-being and reducing psychological distress. Future studies could consider whether these effects can be further enhanced with booster interventions.