A young man was followed-up over three years who had severe obsessive-compulsive rituals and ruminations, interpersonal deficits, complicating depression and a history of childhood autism. Intensive behavioural treatment was given in an operant framework, with exposure in vivo, modelling, response prevention and social skills training. Compulsive rituals improved markedly and lastingly, but ruminations and social defects persisted. When intercurrent depression occurred dothiepin facilitated behavioural treatment. Adjustment remained fragile. Minimum maintenance treatment in the community could not be adequately arranged, so that gains made in hospital were partly lost at follow-up, despite continuing improvement in rituals.