Group therapy for adolescents with repeated self harm: randomised controlled trial with economic evaluation.

To examine the effectiveness and cost-effectiveness of group therapy for self harm in young people. Two arm, single (assessor) blinded parallel randomised allocation trial of a group therapy intervention in addition to routine care, compared with routine care alone. Randomisation was by minimisation controlling for baseline frequency of self harm, presence of conduct disorder, depressive disorder, and severity of psychosocial stress. Adolescents aged 12-17 years with at least two past episodes of self harm within the previous 12 months. Exclusion criteria were: not speaking English, low weight anorexia nervosa, acute psychosis, substantial learning difficulties (defined by need for specialist school), current containment in secure care. Setting Eight child and adolescent mental health services in the northwest UK. Manual based developmental group therapy programme specifically designed for adolescents who harm themselves, with an acute phase over six weekly sessions followed by a booster phase of weekly groups as long as needed. Details of routine care were gathered from participating centres. Primary outcome was frequency of subsequent repeated episodes of self harm. Secondary outcomes were severity of subsequent self harm, mood disorder, suicidal ideation, and global functioning. Total costs of health, social care, education, and criminal justice sector services, plus family related costs and productivity losses, were recorded. 183 adolescents were allocated to each arm (total n = 366). Loss to follow-up was low (