Feasibility randomised controlled trial of a brief psychological intervention for adolescents with borderline personality disorder symptoms delivered with schools and colleges.

Background: There is an urgent need for accessible interventions to facilitate early intervention for young people with borderline personality disorder (BPD) symptoms. Existing evidence-based interventions for adolescent BPD are highly resource-intensive, and few young people with BPD symptoms have access to timely treatment. We adapted a brief psychological treatment for adolescent BPD symptoms previously provided within secondary mental health services for delivery within schools and colleges. This study aimed to assess the feasibility of evaluating the effectiveness and cost-effectiveness of this intervention (BEST (brief education support treatment)) in a future randomised controlled trial (RCT).

Methods: The feasibility RCT involved 12 schools and colleges. Eligible participants were aged 13-18 years and self-reported BPD symptoms above a clinical threshold and a history of repeated self-harm. Over 9 months, 32 participants were randomised to receive either the BEST intervention plus treatment as usual (TAU) or TAU alone. Participants were assessed at baseline and 12 and 24 weeks. A mixed-methods process evaluation was conducted.

Results: Recruitment was slower than anticipated, but participant retention was high (89.5% at 12 weeks and 73.7% at 24 weeks). Performance of all outcome measures was satisfactory. Fidelity of intervention delivery was high (93.5% adherent), and we did not identify any evidence of contamination of the control arm. The intervention was perceived by staff and young people as beneficial to participants, practitioners and the wider school/college and therefore highly acceptable.

Limitations: The study was disrupted by the closure of schools and colleges in response to the COVID-19 pandemic. This reduced the window for participant recruitment and limited data collection.

Conclusions: The intervention was delivered successfully within schools and colleges and was acceptable to staff and young people. The findings provide support for continuing this programme of research and should inform the design of a future evaluation of intervention outcomes.

Trial Registration Number: ISRCTN16862589.