Group‑based psychoeducation for relatives of patients with bipolar disorder — a large-scale real‑world randomised controlled trial - the R‑bipolar RCT

Relatives of patients with bipolar disorder (BD) often experience substantial burden, psychological distress, and depressive symptoms. Existing research on group-based psychoeducation for relatives is characterised by small study populations and resource-intensive interventions. The present study addressed an important research gap by conducting a large randomised controlled trial to evaluate whether group-based psychoeducation for relatives of patients with BD improves mood stabilisation and other key outcomes in relatives. This study evaluated a brief, large-group psychoeducation programme (six sessions, ~ 30 participants) already implemented in clinical practice for relatives of patients with newly diagnosed BD. We conducted a large-scale, pragmatic, randomised controlled parallel-group superiority trial. Participants were randomised 1:1 to group-based psychoeducation or a waitlist control group. The primary outcome was mood instability, assessed using daily smartphone-based self-reports, reflecting psychological distress. Secondary outcomes were the relative’s burden according to the Burden Assessment Scale and the relative’s knowledge about BD according to the Bipolar Disorder Knowledge Scale, measured at baseline and follow-up 4–6 weeks after the last session. Data were analysed using linear mixed-effects models in accordance with the intention-to-treat principle. A satisfaction questionnaire was also administered at follow-up. A total of 206 relatives were included. We found no significant effect on Mood Instability ( p = 0.4) or the Burden Assessment Scale ( p = 1.0), but we observed significant improvements on the Bipolar Disorder Knowledge Scale ( p = 0.002). While no effects were found on Mood Instability or caregiver burden, knowledge about BD improved significantly in the intervention group. Participants had lower than expected distress at baseline, which may have introduced ceiling effects. Findings from the satisfaction questionnaire and a concurrent qualitative study were used to discuss the findings, and indicated that while the large-group format was well-accepted, the experience of peer-support could be strengthened. ClinicalTrials.gov identifier NCT06176001, registered 20,231,219. The study is approved by the data agency (P2021809).