Psychological flexibility and the moderating role of the therapeutic working alliance in Acceptance and Commitment Therapy in Daily Life (ACT-DL) in an early psychosis sample

Background: We investigated treatment effects of Acceptance and Commitment Therapy in Daily Life (ACT-DL) on psychological flexibility (PF) and the moderating role of the therapeutic working alliance on these effects in patients with early psychosis. Methods: ACT-DL is an ecological momentary intervention (EMI) combining face-to-face ACT with a smartphone app. In the multi-center INTERACT randomized controlled trial, n=148 early psychosis individuals were randomized to either treatment as usual (TAU as the control condition, n=77) or to ACT-DL in addition to TAU (ACT-DL + TAU as the experimental condition, n=71). We assessed global PF and the therapeutic alliance with self-report questionnaires. In addition, we used the experience sampling methodology (ESM) to assess PF with a momentary (in-the-moment and since-the-previous-beep openness) and an evening (daily PF) questionnaire. Assessments took place at baseline, post-intervention (POST), six (FU6), and twelve months (FU12) follow-up. Results: Global (B=19.49 to 33.14; all P-values<.001) and daily PF (B=0.68; P-value<.001) improved equally in both conditions at each time point. Individuals in the ACT-DL condition improved more than those in TAU on momentary openness (in-the-moment openness at POST (B=0.32; P-value=0.007) and since-the-previous-beep openness at POST (B=0.33; P<.001) and FU6 (B=0.23; P-value=0.025). Client-perceived working alliance moderated in-the-moment openness such that larger improvements in openness at POST (B=0.05; P-value<.001) were found in ACT-DL in individuals with higher working alliance scores. Conclusion: Our results provide partial support for the capability of ACT-DL to improve daily life measures of openness, and emphasize the importance of the therapeutic relationship in supporting processes of change.