Randomised controlled trial of a brief theory-based online intervention to reduce self-harm.

backgroundForming 'if-then' plans has been shown to reduce self-harm among people admitted to hospital following an episode of self-harm.

aimsTo explore whether the same intervention, delivered online, could prevent future self-harm among a large community sample who had previously self-harmed.

methodUK adults were recruited to a randomised controlled trial and received either an intervention to reduce self-harm or one to reduce sedentariness (control group). Randomisation was stratified to ensure both groups were representative of the UK population. There were three primary outcomes: non-suicidal self-injury (NSSI), suicidal ideation and suicide attempts, assessed at baseline and 6 months post-intervention.

resultsParticipants (1040) were randomised to the intervention (

conclusionsThis web-based intervention has limited utility for reducing self-reported self-harm or suicidal ideation in adults with a history of self-harm. Further work is needed to improve the effectiveness of brief interventions for self-harm aimed at adults living in the community and to understand the conditions under which the intervention may or may not be effective.