BI-REAL: A 12-session DBT skills group intervention adapted for bipolar disorder – A feasibility randomised pilot trial

International guidelines endorse psychological treatment for Bipolar Disorder (BD); however, the absence of a recognised gold-standard intervention requires further research. A Dialectical Behaviour Therapy (DBT) skills group intervention with 12 sessions was developed. This pilot randomised controlled trial (RCT) aims to evaluate the feasibility, acceptability, and outcomes variance of Bi-REAL – Respond Effectively, Assertively, and Live mindfully, tailored for individuals with BD, in preparation for a future RCT. Methods 52 participants (female = 62.7 %; mean age = 43.2 ± 11.1) with BD were randomised by blocks to either the experimental group (EG; n = 26; Bi-REAL + Treatment as Usual, TAU) receiving 12 weekly 90-minute sessions, or the control group (CG; n = 26, TAU). Feasibility and acceptability were assessed with a multimethod approach (qualitative interviews, semi-structured clinical interviews and a battery of self-report questionnaires – candidate main outcomes Bipolar Recovery Questionnaire (BRQ) and brief Quality of Life for Bipolar Disorder (QoL.BD)). All participants were evaluated at baseline (T0), post-intervention (T1) and 3-month follow-up (T2). Results Acceptability was supported by participants' positive feedback and ratings of the sessions and programme overall, as well as the treatment attendance (86.25 % of sessions attended). The trial overall retention rate was 74.5 %, with CG having a higher dropout rate across the 3-timepoints (42.31 %). A significant Time × Group interaction effect was found for BRQ and QoL.BD with the intervention group presenting a larger decrease in symptoms (p < .05). Limitations The assessors were not blind at T1 (only at T2). Recruitment plan was impacted due to COVID-19 restrictions and replication is questionable. High attrition rates in the CG. Conclusions The acceptability of Bi-REAL was sustained, and subsequent feasibility testing will be necessary to establish whether the retention rates of the overall trial improve and if feasibility is confirmed, before progressing to a definitive trial.