Large improvement of mental health during in outpatient short-term group psychotherapy treatment—a naturalistic pre-/post-observational study

BACKGROUND: Group psychotherapy is an effective treatment for patients with mental health issues. This study aims to evaluate data on the effectiveness of a cost-free short-term outpatient group psychotherapy project for patients with mixed mental health issues in Tyrol, Austria. METHODS: In this naturalistic observational study, outpatients taking part in the psychotherapeutic group treatment between spring 2018 and spring 2020 were included. Patients completed the patient health questionnaire (PHQ-D), an item of the working ability index (WAI) and single items on symptom burden, treatment expectation and perceived benefit before the first (T0) and/or last group session (T1). Mean changes were investigated using repeated measure analyses of variance (rANOVA). RESULTS: A total of 98 patients were included in the study. Statistically significant improvements with medium to large effect sizes were observed for depression (η(2) = 0.22, p < 0.001), somatization (η(2) = 0.10, p = 0.008), anxiety (η(2) = 0.18, p < 0.001), and subjective working ability (η(2) = 0.22, p < 0.001). Neither age (p = 0.85), sex (p = 0.34), baseline symptoms (p = 0.29–0.77), nor previous experience with individual (p = 0.15) or group psychotherapy (p = 0.29) were associated with treatment outcome. However, treatment expectation at baseline was significantly associated with the patients’ perception of the treatment benefit (r = 0.39, p < 0.001). CONCLUSION: Our study highlights the benefit of outpatient short-term group psychotherapy for individuals with mental health issues. Group psychotherapy should be offered free of charge to individuals with mental health issues by social health providers.