Randomised controlled trials (RCTs) that compared a specific psychological treatment to treatment as usual in adolescent patients (aged up to 18) who have self harmed at least once were eligible for inclusion. Studies were required to evaluate participant engagement with therapy; engagement was defined as attending at least four sessions of a psychotherapeutic intervention. Specific psychological treatments were defined as theoretically coherent non-pharmacological interventions which were replicable. Self-harm was defined as self-poisoning or self-injury irrespective of intent. Studies in which adolescents with self-harm were a minority were excluded as were studies which contained any type of pharmacological intervention.
A range of specific psychological treatments were included; these utilised different therapeutic approaches, such as cognitive, behavioural and psychodynamic methods. Delivery of interventions was group-based, individual or family-based. Maximum and minimum age range of participants was 12 to 18 years, where reported. Participants included teenagers who had attempted suicide, self-poisoned or repeatedly self-harmed and those diagnosed with a borderline personality disorder.
Two reviewers independently assessed the studies for inclusion.