Both aggression and drug abuse consist of several component behaviors that lie on a continuum. For drug abuse, the essential behavior is the use of one or more psychoactive substances to achieve a change in mood, perception, or other cognitive or sensory modality of the brain. Aggression involves a range of behaviors from ideation, plans, and verbal expression to overt acts. When viewed from a developmental perspective, chronic aggressive behavior among adolescents is associated with other concurrent antisocial behaviors in aggressive conduct disorders. Early onset conduct disorders likely increase the risk for early initiation into drug use and later abuse. Biological factors play a significant role in the development of aggressive behavior. Multiple risk factors present in adolescents who abuse drugs and manifest aggressive or violent behavior require a comprehensive assessment of many areas of potential psychopathology and psychosocial functioning. Discontinuation of the adolescent's drug abuse and abstinence are the most important intervention targets in the treatment of adolescents who exhibit aggressive behavior and abuse drugs. Treatment strategies include social skills training, behavioral contracting, relapse prevention, and medication. A comprehensive approach to controlling aggressive behavior and drug abuse is recommended that targets multiple problems and deficits in the adolescent's psychosocial functioning. 70 references