The effectiveness of group-based psychological interventions for emotional distress in non-clinical adult populations: a systematic review

BACKGROUND: The demand for healthcare due to emotional distress from daily challenges has grown rapidly. Many individuals do not meet criteria for a mental disorder, yet psychotropic medication is often the first-line response. Group-based psychological interventions have emerged as alternatives for reducing emotional distress, but their effectiveness in non-clinical populations remains unclear. OBJECTIVES: This systematic review examines the effectiveness of group-based interventions in reducing emotional distress among non-clinical adults. METHODS: A comprehensive search was conducted across major databases from January 2013 to March 2025. Eligible studies included interventions targeting adults with non-clinical distress. Studies were excluded if participants had a diagnosed mental disorder or if the absence of diagnosis was unclear. RESULTS: A total of 4,942 records were identified (3,980 through database searching and 962 through backward citation tracking), including 20 studies. Most interventions produced significant improvements. Mindfulness-based approaches were most frequent, either alone or integrated with cognitive-behavioral therapy (CBT) or acceptance and commitment therapy (ACT). Relaxation techniques also showed independent benefits. DISCUSSION: Most interventions were psychoeducational, with mindfulness most widely applied. No significant differences were observed between intervention types. Findings highlight the potential of diverse psychological strategies to improve well-being in non-clinical adults, while stressing the need for further evaluation.