The family is the center of social life for children. During adolescence, the peer group begins to replace the family as the child's primary social focus. Peer groups are often established because of distinctions in dress, appearance, attitudes, hobbies, interests, and other characteristics that may seem profound or trivial to outsiders. Initially, peer groups are usually same-sex but typically become mixed later in adolescence. These groups assume an importance to adolescents because they provide validation for the adolescent's tentative choices and support in stressful situations.

Adolescents who find themselves without a peer group may develop intense feelings of being different and alienated. Although these feelings usually do not have permanent effects, they may worsen the potential for dysfunctional or antisocial behavior. At the other extreme, the peer group can assume too much importance, also resulting in antisocial behavior. Gang membership is more common when the home and social environments are unable to counterbalance the dysfunctional demands of a peer group (see Problems in Adolescents: Behavioral Problems in Adolescents).

Doctors should screen all adolescents for mental health disorders, such as depression, bipolar disorder, and anxiety. Mental health disorders increase in incidence during this stage of life and may result in suicidal thinking or behavior. Psychotic disorders, such as schizophrenia, although rare, most often come to attention during late adolescence. Eating disorders, such as anorexia nervosa and bulimia nervosa (see Eating Disorders: Definition of Eating Disorders), are relatively common among girls and may be difficult to detect because adolescents go to great lengths to hide the behaviors and weight changes.

Substance use typically begins during adolescence. More than 70% of adolescents in the United States try alcohol before they graduate high school. Binge drinking is common and leads to both acute and chronic health risks. Research has shown that adolescents who start drinking alcohol at a young age are more likely to develop an alcohol use disorder as an adult. For example, adolescents who start drinking at age 13 are 5 times more likely to develop an alcohol use disorder than those who start drinking at age 21. Almost 50% of U.S. adolescents try cigarettes and more than 40% try marijuana while they are in high school. Use of other drugs is much less common, although misuse of prescription drugs, including drugs for pain and stimulants, is on the rise.

Parents can have a strong positive influence on their children by setting a good example (such as using alcohol in moderation and avoiding use of illicit drugs), sharing their values, and setting high expectations regarding staying away from drugs. Parents also should teach children that prescription drugs should be used only as directed by a doctor. All adolescents should be confidentially screened for substance use. Appropriate advice should be given as part of routine health care because even very brief interventions by doctors and health care practitioners have been shown to decrease substance use by adolescents.

Last full review/revision February 2009 by Sharon Levy, MD, MPH