Oppositional defiant transtorno is a persistent padrão (e.g., 6 months or more) of markedly defiant, disobedient, provocative or spiteful behaviour that occurs more frequently than is typically observed in individuals of comparable age and developmental level and that is not restricted to interaction com siblings. Oppositional defiant transtorno may be manifest in prevailing, persistent angry or irritable mood, often accompanied by grave temper outbursts or in headstrong, argumentative and defiant behaviour. The behaviour padrão is of sufficient severity to result in significant impairment in personal, family, social, educational, occupational or other important areas of functioning