From parent levels
ChapterVMental and behavioural disordersOpen
BlockF90-F98Behavioural and emotional disorders with onset usually occurring in childhood and adolescenceOpen
CategoryF91Conduct disordersOpen
Disorders characterized by a repetitive and persistent pattern of dissocial, aggressive, or defiant conduct. Such behaviour should amount to major violations of age-appropriate social expectations; it should therefore be more severe than ordinary childish mischief or adolescent rebelliousness and should imply an enduring pattern of behaviour (six months or longer). Features of conduct disorder can also be symptomatic of other psychiatric conditions, in which case the underlying diagnosis should be preferred.
Examples of the behaviours on which the diagnosis is based include excessive levels of fighting or bullying, cruelty to other people or animals, severe destructiveness to property, fire-setting, stealing, repeated lying, truancy from school and running away from home, unusually frequent and severe temper tantrums, and disobedience. Any one of these behaviours, if marked, is sufficient for the diagnosis, but isolated dissocial acts are not.
Oppositional defiant disorder
Conduct disorder, usually occurring in younger children, primarily characterized by markedly defiant, disobedient, disruptive behaviour that does not include delinquent acts or the more extreme forms of aggressive or dissocial behaviour. The disorder requires that the overall criteria for F91.- be met; even severely mischievous or naughty behaviour is not in itself sufficient for diagnosis. Caution should be employed before using this category, especially with older children, because clinically significant conduct disorder will usually be accompanied by dissocial or aggressive behaviour that goes beyond mere defiance, disobedience, or disruptiveness.