Acceptance-based behavior therapy for depression with psychosis: Results from a pilot feasibility randomized controlled trial

Acceptance-based depression and psychosis therapy (ADAPT), a mindfulness/acceptance-based behavioral activation treatment, showed clinically significant effects in the treatment of depression with psychosis in a previous open trial. The goal of the current study was to further test the feasibility of ADAPT to determine the utility of testing it in a future clinical trial, following a stage model of treatment development. Feasibility was determined by randomizing a small number of patients (N=13) with comorbid depression and psychosis to medication treatment as usual plus enhanced assessment and monitoring versus ADAPT for 4 months of outpatient treatment. Both conditions were deemed acceptable by patients. Differences in between-subjects effect sizes favored ADAPT posttreatment and were in the medium to large range for depression, psychosocial functioning, and experiential avoidance (ie, the target mechanism). Thus ADAPT shows promise for improving outcomes compared with medications alone and requires testing in a fully powered randomized trial.