The intervention group will receive a culturally adapted version of the yet well-validated START NOW training. The skills taught within START NOW aim to change dysfunctional negative attitudes and behaviour, improve emotion regulation capacities and enhance the ability to achieve individual goals by addressing key aspects of mental health and resilience. The training includes 10 group sessions including exercises and discussion.

The sessions will be held by a trained facilitator (staff member of institution, social worker, or else) with the same cultural background in the respective language (depending on group constellation) and supervised by a certified START NOW trainer from the START NOW team.

The control group will receive treatment as usual.

The START NOW skills-training combines aspects of cognitive behavioral therapy (CBT), motivational interviewing (MI), dialectical behavior therapy (DBT), Acceptance and Commitment Therapy (ACT) and trauma-sensitive care. Studies in different contexts have shown START NOW's effectiveness in terms of reducing behavioral problems, reducing hospitalization rates, improving mental health functioning and increasing satisfaction rates. The culturally adapted version will be contextually adapted to different cultural backgrounds and the experience of migration. In ten sessions, participants learn about emotions and are introduced to the START NOW skills. These skills, called "SLOW DOWN", "TAKE A STEP BACK", "ACCEPT", "RESPECT" and "TAKE ACTION", are strategies or techniques that can be used to better manage stress and difficult emotions.

Depression and anxiety will be measured by the Hopkins-Symptom-Checklist-25 (HSCL-25) questionnaire. The HSCL-25 is a 25-item self-report questionnaire, on which participants rate if physical, emotional, or psychological symptoms indicating depression, anxiety, and trauma have affected them over the past week. Answers are given on a 4-point Likert Scale (1 = not at all; 4 = extremely), and total scores can range from 25 to 100, with higher scores indicating greater levels of depression, anxiety and trauma, respectively. We chose symptoms of depression and anxiety as the primary endpoint because of their high self-reported prevalence of up to 42% in refugee populations.

Depression and anxiety will be measured by the Hopkins-Symptom-Checklist-25 (HSCL-25) questionnaire. The HSCL-25 is a 25-item self-report questionnaire, on which participants rate if physical, emotional, or psychological symptoms indicating depression, anxiety, and trauma have affected them over the past week. Answers are given on a 4-point Likert Scale (1 = not at all; 4 = extremely), and total scores can range from 25 to 100, with higher scores indicating greater levels of depression, anxiety and trauma, respectively. We chose symptoms of depression and anxiety as the primary endpoint because of their high self-reported prevalence of up to 42% in refugee populations.

Perceived stress will be measured by the Perceived Stress Scale-10 (PSS-10). The PSS-10 is a 10-item self-report questionnaire including two subscales, on which participants report life as unpredictable, uncontrollable, and overloading over the previous month. Answers are given on a 5-point Likert Scale (0 = never, 4 = very often). Higher scores indicate higher levels of perceived stress. We chose perceived stress as a secondary endpoint because the many pre-, peri- and post-migration stressors that are risk factors for refugees' mental health could be better managed through the intervention aimed at improving distress tolerance.