This disorder is more prevalent in boys than girls. Some studies have shown that 20% of the school-age population is affected, but most experts believe this figure is inflated due to changing cultural definitions of normal childhood behavior and other possible racial, cultural, and gender biases.

Onset typically occurs by age 8. The cause of this disorder is unknown, and may be due to a combination of biology and parenting or environmental factors.

• arguing with adults
• loss of temper
• angry and resentful of others
• actively defies adults' requests
• spiteful or vindictive behavior
• blames others for their own mistakes
• is touchy or easily annoyed
• few or no friends or loss of previous friends
• constant trouble in school

The pattern of behaviors must be distinguished from what is commonly observed in other children of similar age and developmental level, and must result in significant social or academic problems.

Evaluation by a psychiatrist or psychologist may be recommended. In children and adolescents, depression and attention-deficit /hyperactivity disorder (ADHD) may cause similar disturbances in behavior, and should be considered as alternate or additional diagnoses.

The best treatment for the child is individual psychotherapy. The parents should also learn behavioral management skills. Medication may be helpful if the behaviors occur in the course of another condition (such as depression, childhood psychosis, or ADHD).

Punitive treatments like boot camps and "behavioral modification" schools which restrict contact with parents and place the child among other disturbed children can do more harm than good.

Consistency in rules and fair consequences should be practiced in the child's home. Punishments should not be overly harsh or inconsistently applied.

Appropriate behaviors should be modeled by the adults in the household. Abuse and neglect increase the chances that this condition will occur.