Sometimes it's difficult to recognize the difference between a strong-willed or emotional child and one with oppositional defiant disorder. It's common for children to show oppositional behavior at certain stages of development. Symptoms of ODD generally begin during preschool years. Sometimes ODD may develop later, but almost always before the early teen years. Oppositional and defiant behaviors are frequent and ongoing. They cause severe problems with relationships, social activities, school and work, for both the child and the family. ODD ODD Emotional and behavioral symptoms of ODD generally last at least six months. They include angry and irritable mood, argumentative and defiant behavior, and hurtful and revengeful behavior. ODD Angry and irritable mood Angry and irritable mood 
Often and easily loses temper.
Is frequently touchy and easily annoyed by others.
Is often angry and resentful.
 Argumentative and defiant behavior Argumentative and defiant behavior 
Often argues with adults or people in authority.
Often actively defies or refuses to follow adults' requests or rules.
Often annoys or upsets people on purpose.
Often blames others for their own mistakes or misbehavior.
 Hurtful and revengeful behavior Hurtful and revengeful behavior 
Says mean and hateful things when upset.
Tries to hurt the feelings of others and seeks revenge, also called being vindictive.
Has shown vindictive behavior at least twice in the past six months.
 Severity Severity ODD can be mild, moderate or severe: ODD 
Mild. Symptoms occur only in one setting, such as only at home, school, work or with peers.
Moderate. Some symptoms occur in at least two settings.
Severe. Some symptoms occur in three or more settings.
 For some children, symptoms may first be seen only at home. But with time, problem behavior also may happen in other settings, such as school, social activities and with friends.