Children sometimes argue, are aggressive, or act angry or defiant around adults. A behaviour disorder may be diagnosed when these disruptive behaviours are uncommon for the child’s age at the time, persist over time, or are severe.  Because disruptive behaviour disorders involve acting out and showing unwanted behaviour towards others they are sometimes called externalizing disorders.

When children act out persistently so that it causes serious problems at home, in school, or with peers, they may be diagnosed with Oppositional Defiant Disorder (ODD). ODD usually starts before 8 years of age, but no later than by about 12 years of age. Children with ODD are more likely to act oppositional or defiant around people they know well, such as family members, a regular care provider, or a teacher. Children with ODD show these behaviours more often than other children their age.

Examples of ODD behaviours include:

• Often being angry or losing one’s temper
• Often arguing with adults or refusing to comply with adults’ rules or requests
• Often resentful or spiteful
• Deliberately annoying others or becoming annoyed with others
• Often blaming other people for one’s own mistakes or misbehaviour.