Supplementary Material for: Psychotherapy for Chronic In- and Outpatients with Common Mental Disorders: The “Choose Change” Effectiveness Trial

Introduction: Treatment non-response occurs regularly, but psychotherapy is seldom examined for such patients. Existing studies targeted single diagnoses, were relatively small, and paid little attention to treatment under real-world conditions. Objective: The Choose Change-trial tested whether psychotherapy was effective in treating chronic patients with treatment non-response in a transdiagnostic sample of common mental disorders across two variants of treatment delivery (inpatient and outpatient). Methods: The controlled nonrandomized effectiveness trial was conducted between May 2016 and May 2021. The study took place in two psychiatric clinics with N = 200 patients (n = 108 inpatients & n = 92 outpatients). Treatment variants were integrated inpatient care vs. outpatient care based on Acceptance and Commitment Therapy (ACT) for approximately 12 weeks. Therapists delivered individualized and non-manualized ACT. Main outcome measures were symptoms (Brief Symptom Check List; BSCL); well-being (Mental Health Continuum; MHC-SF) and functioning (WHO Disability Assessment Schedule; WHO-DAS). Results: Both inpatients and outpatients showed decreases in symptomatology (i.e., BSCL – d = .68) and increases in well-being and functioning (MHC-SF - d = .60 & WHO-DAS d = .70), with more improvement in the inpatients during treatment. Both groups maintained gains one year following treatment, and the groups did not significantly differ from each other at this timepoint. Psychological flexibility moderated impact of stress on outcomes. Conclusions: Psychotherapy as practiced under routine conditions is effective for a sample of patients with common mental disorders, a long history of treatment experience and burden of disease, in both inpatient and outpatient settings.