BackgroundAsylum seekers and refugees are at great risk for developing mental disorders. Afghan refugees are a particularly vulnerable group with a low average education and mental health literacy level. Traumatic experiences and hardship before and during migration are predictive of mental health problems. However, post-migration living difficulties (PMLDs) also account for a large proportion of mental distress in such populations, which, critically, are not sufficiently considered in treatment protocols and research investigations. Indeed, the evidence base for the treatment of refugees and asylum seekers is sparse and limited mainly to trauma-specific treatments, where refugees may likely suffer from other mental health problems such as depression or anxiety.Methods/designThis trial is the first evaluation of a short-term, transdiagnostic treatment protocol for treatment-seeking Afghan refugees which addresses mental health problems and PMLDs while using an adapted version of the Problem Management Plus (PM+) protocol. Here, we will investigate the efficacy of an intervention manual with a prospective, single-center, randomized, assessor-blind, two-group trial among refugees who are on a waiting list for professional mental health treatment. Furthermore, we will investigate participants’ subjective experiences with the intervention manual via in-depth interviews. One hundred twenty people will be assessed and randomly allocated to either the intervention arm or a treatment-as-usual arm. Clinical psychologists will conduct the treatment, and the sessions will take place with a Dari interpreter. The protocol consists of six 90-min sessions. The primary endpoint is the general symptom distress measure, assessed with the General Health Questionnaire 28 (GHQ-28). Secondary endpoints are the Post-Migration Living Difficulties Checklist (PMLDC), the International Trauma Questionnaire (ITQ), the World Health Organization Quality of Life Questionnaire (WHOQOL-BREF), the Psychological Outcome Profile (PSYCHLOPS), service and health care use (assessed with several items), and the Immigrant Integration Index (IPL-12).DiscussionThis trial may provide substantial evidence for a brief transdiagnostic psychological intervention. Here, we intend to contribute to the treatment of mental health problems among Afghan refugees. The assessment of subjective experience with this treatment manual, as well as the evaluation of its clinical applicability, may optimize treatment acceptance and outcomes across a wide range of mental health problems among refugees.Trial registrationGerman Clinical Trials Register (DRKS) registration number: DRKS00016538. Universal Trial Number: U1111-1226-3285. Registered on January 7, 2019. https://www.drks.de/drks_web/setLocale_EN.do