Young people with conduct disorder usually have little concern for others and repeatedly violate the basic rights of others and the rules of society. Conduct disorder causes children and adolescents to act out their feelings or impulses in destructive ways. The offenses these children and adolescents commit often grow more serious over time. Such offenses may include lying, theft, aggression, truancy, the setting of fires, and vandalism. Current research has yielded varying estimates of the number of young people with this disorder, ranging from one to four of every 100 children 9 to 17 years of age (U.S. Department of Health and Human Services, 1999).