Adolescence is a time for developing independence. Typically, adolescents exercise their independence by questioning, and sometimes breaking, rules. Parents and doctors must distinguish occasional errors of judgment from a pattern of misbehavior that requires professional intervention. The severity and frequency of infractions are guides. For example, regular drinking, frequent episodes of fighting, truancy, and theft are much more significant than isolated episodes of the same activities. Other warning signs include deterioration of performance at school and running away from home. Of particular concern are adolescents who cause serious injury or use a weapon in a fight