Supplementary Material for: Effectiveness of psychotherapeutic consultation at work compared to care as usual for employees with common mental disorders or subthreshold symptoms: A randomized controlled multicenter trial in Germany

Introduction
Common mental disorders (CMD) are often work-related, impact work ability and are undertreated. This trial investigates whether psychotherapeutic consultation at work (PT-A) is more effective than care as usual (CAU) in reducing days of sickness absence (DOSA) among affected employees.
Methods
A randomized controlled trial (RCT) in five German study centers included employees with CMD or global assessment of functioning (GAF) <81, working ≥15 hours/week, recruited via companies and media. After baseline, participants were randomized 1:1 to intervention (IG: up to 16 individual psychotherapy sessions over nine months) or control (CG: diagnostic session + follow-up call) group. The primary outcome was self-reported DOSA in the last six months at 15 months post-baseline (T2). Analyses used intention-to-treat.
Results
From 09/2021 to 01/2023, 550 participants, 246 male, 301 female, and 1 diverse, were randomized to IG (n=279) and CG (n=270). 403 participants (74%) were first-time users of mental health care. DOSA at T2 were 21 days (SD=39) in the IG (n=206) versus 22 days (SD=39) in the CG (n=161), no significant treatment effect was observed ([0.65; 1.32], p=0.679).
Conclusion
PT-A did not significantly reduce DOSA compared to CAU. However, secondary outcomes showed considerable improvement of clinical symptoms such as depression and anxiety and return-to-work self-efficacy. Therefore, longer observation periods may be needed to assess the effects on DOSA. Moreover, compared to clinical experiences, the high number of men and first-time users indicate an improved accessibility for underserved groups of employees.