We will conduct a randomized control trial to investigate whether and to what extent regular and guided group physical activity over 12 weeks (2 sessions à 1 hour/week) improves physical fitness and (physio-)psychological functions (like subjective sleep, mental toughness, perceived stress, self-efficacy, etc.), as well as participation skills and the ability to work, in claimants for a disability pension due to psychiatric disorders, whose ability to work had recently been assessed by means of a psychiatric expert opinion. The control group is designed very similar and implies predominantly sedentary leisure time group activities (e.g. playing board games, doing handicrafts). Measures will be performed at baseline, post-test, and at follow ups three and twelve months after post-test, some variables will additionally be assessed 4-weekly during the intervention. We expect that intervention group participants will report and show, respectively, more improved physical fitness, (physio-)psychological functioning and participations skills, as well as increased ability to work, compared to the control group.

Inclusion Criteria:

• Claimants for a disability pension due to a mental disorder, whose ability to work has been recently assessed by means of a psychiatric expert opinion
• Both genders
• 18-55 years old
• Clinical diagnosis of depressive disorder, somatoform disorder, anxiety disorder, personality disorder
• Sufficient competence in understanding, speaking and reading German
• Sufficient cognitive, emotional and social level of functioning to be able to participate in a group
• Physical Activity Readiness Questionnaire without evidence for reduction
• or: Physical activity readiness certificated by the general practitioner
• Informed consent

Exclusion Criteria:

• Comorbidity with a somatic disorder that limits the ability for physical exercises
• Pregnancy
• Ongoing disturbance of the study