A form of antisocial behavior disorder characterized by opposition to authority figures such as parents and teachers, and by excessive anger and hostility.

Depending on the population, 2-6% of children have oppositional-defiant disorder. Oppositional-defiant disorder is similar to conduct disorder, without the more severe behavior components of aggression, property destruction, deceit, and theft. Oppositional-defiant children often go on to develop conduct disorder. Many children, especially during transitional periods such as preschool and adolescence, exhibit transient oppositional behavior towards parents and peers that will decline as they mature. If oppositional behavior is initiated during adolescence in particular it is probably part of the child's process of individuation, and should not be mistaken for a disorder. Children with oppositional-defiant disorder (1) are oppositional much more frequently than other children of their age and (2) increase their oppositional behaviors rather than decrease them with age. Disobedience and hostility usually appear first...