Supplementary materials to: A mental imagery micro-intervention to increase positive affect in outpatient CBT sessions (PACIfIC): Study protocol of a randomized controlled implementation trial

Background: Recent findings indicated that mental disorders are associated with both an up-regulation of negative affect and a down-regulation of positive affect (PA) as distinct processes. Established treatment approaches focus on the modification of problems and negative affect only. Experimental paradigms in healthy samples and research on strengths-based approaches showed that fostering PA may improve psychotherapy process and outcome. Specific and easily implementable interventions targeting PA in treatment sessions are scarce. Mental imagery was shown to be a promising strategy for boosting positive emotional experiences. Method: The PACIfIC-study is planned as a longitudinal randomized-controlled trial in the context of cognitive behavioral therapy, implemented at a German outpatient training and research center. In the process analysis, trajectories of PA over the first twelve treatment sessions will be examined with weekly questionnaires. In the intervention analysis, a six-minute positive mental imagery intervention to enhance PA will be developed and tested. The intervention is implemented with loudspeakers at the beginning of each session for a standardized induction of PA. The experimental group will be compared to an active control group (neutral mental imagery) and treatment as usual. Procedures in all treatment arms are parallelized. Main outcomes after twelve sessions of psychotherapy will be psychosocial resources, resilience and self-esteem (theory-driven), as well as psychopathology and working alliance (secondary outcome). Multilevel modeling will be conducted to address the nested data structure. Conclusion: Study results may have implications on the consideration of positive constructs in mental disorders and the implementation of strengths-based interventions in psychotherapy.