Antisocial behaviour is the most common reason for referral to child mental health services (National Institute for Health and Care Excellence, 2013). It is a clinical problem of considerable importance, because there is a marked tendency for it to persist, and the long-term outcome includes antisocial personality disorder and criminality. Longitudinal studies have shown that children with conduct disorder at the age of 7 are ten times more likely to be criminals in adulthood (Fergusson et al, 2005). Effective treatments are now available, although not yet widely used in the UK.

We use the term ‘antisocial behaviour’ to include children who do not necessarily meet the strict definitions of conduct disorder or oppositional defiant disorder, for which DSM-5 (American Psychiatric Association, 2013) and ICD-10 (World Health Organization, 1993) have quite similar diagnostic criteria. For both schemes, the diagnosis of conduct disorder requires a repetitive and persistent pattern of behaviour in which the basic rights of others or major age-appropriate social norms are violated. DSM-5 stresses that the disturbance must cause clinically significant impairment in social, occupational or academic functioning, which is implicit in ICD-10. DSM-5 requires that three of the symptoms/behaviours in Box 5.1 be present during the preceding 12 months and one during the preceding 6 months, whereas ICD-10 merely specifies that three symptoms must be present, but requires one symptom to have been present within the previous month. For oppositional defiant disorder, both DSM-5 and ICD-10 require four symptoms/behaviours from the list in Box 5.2 to have been present for the preceding six months. Although DSM-5 views oppositional defiant disorder as a common precedent to conduct disorder, ICD-10 regards it as a milder form of conduct disorder, and stipulates that no more than two of the symptoms in Box 5.1 should be present.

The one major change from DSM-IV (American Psychiatric Association, 1994) to DSM-5 is the inclusion of a specifier to designate youths ‘with limited prosocial emotions’ (American Psychiatric Association, 2013). To meet this criterion, individuals must show two or more characteristics of callous-unemotional traits, such as shallow affect, lack of empathy, lack of remorse or guilt, or lack of concern about their performance at school or work during the preceding 12 months.