The Relational Approach to Treating Self-Harm (RELATE): study protocol for a feasibility randomised controlled trial study of cognitive analytic therapy for adults who self-harm versus treatment at usual.

Background: Self-harm is a prevalent behaviour that has a major detrimental impact on a person's life. Psychological therapies have the potential to help, but evidence of effective interventions remains limited. Access and acceptability of interventions can also be a significant challenge, with individuals either being unable to access help or having to endure long waiting lists. Cognitive analytic therapy (CAT) is a time-limited and relationally-focused psychotherapy that may provide a valuable treatment option for people who self-harm. This protocol outlines the methodology for the first feasibility randomised controlled trial (RCT) of CAT for adults that self-harm. The trial will aim to determine the feasibility, acceptability and safety of undertaking larger-scale evaluations of CAT for self-harm within an RCT context.

Method: An RCT design with 1:1 allocation to CAT plus treatment as usual (TAU) or TAU alone. Participants will be adult outpatients with three or more instances of self-harm in the past year (target sample of n = 60). CAT will be 8 one-to-one weekly 60-min sessions plus a follow-up session up to 8 weeks after the last session. Assessments will occur at baseline, 12 weeks and 18 weeks after randomisation. Qualitative interviews with participants will gain insights into the feasibility and acceptability of CAT. Feasibility outcomes will be judged against progression criteria.

Discussion: CAT may be an effective and accessible treatment option for people who self-harm, providing a more relationally orientated alternative to more behavioural therapies. The proposed feasibility RCT is an important first step in evaluating CAT as a treatment for self-harm.

Trial registration: The trial was pre-registered (21/10/22) on ISR CTN (ISRCTN code: ISRCTN75661422).