Definition

Oppositional defiant disorder (ODD) is a disorder found primarily in children and adolescents. It is characterized by negative, disobedient, or defiant behavior that is worse than the normal "testing" behavior most children display from time to time. Most children go through periods of being difficult, particularly during the period from 18 months to three years, and later during adolescence. These difficult periods are part of the normal developmental process of gaining a stronger sense of individuality and separating from parents. ODD, however, is defiant behavior that lasts longer and is more severe than normal individuation behavior, but is not so extreme that it involves violation of social rules or the rights of others.

The mental health professional's handbook, Diagnostic and Statistical Manual of Mental Disorders, fourth edition,...