All young children can be naughty, defiant and impulsive from time to time, which is perfectly normal. However, some children have extremely difficult and challenging behaviours that are outside the norm for their age.

The most common disruptive behaviour disorders include oppositional defiant disorder (ODD), conduct disorder (CD) and attention deficit hyperactivity disorder (ADHD). These three behavioural disorders share some common symptoms, so diagnosis can be difficult and time consuming. A child or adolescent may have two disorders at the same time. Other exacerbating factors can include emotional problems, mood disorders, family difficulties and substance abuse.