Introduction

Conduct disorder is the commonest psychiatric disorder of childhood across the world, and the commonest reason for referral to child and adolescent mental health services. Unlike most disorders, it is entirely defined in terms of the individual's relationship with other people and society. There is a persistent pattern of antisocial behaviour whereby the individual repeatedly breaks social rules and carries out aggressive acts that disturb other people. This persistent tendency typically starts young – aged 2–4 years – and carries on until at least middle age. Thus a substantial proportion of children and adolescents with conduct disorder grow up to be antisocial adults, leading impoverished and destructive lifestyles; a significant minority will develop antisocial personality disorder (psychopathy). The personal impact and cost to society is high, since many domains of living are affected, and many professionals and agencies get involved in managing the sequelae. These include police and the criminal justice system, teachers and the educational system, social workers and housing agencies, and unemployment and benefit payment offices.

Two paradoxes are apparent in society's response to affected individuals. First, despite overwhelming evidence that this is a lifelong affliction, the moment an individual wakes up on the morning of their 18th birthday, they no longer have a psychiatric problem (there is no category of conduct disorder in adulthood). Instead, they are frequently just seen as a nuisance and bad, or sometimes even plain evil.