As developmentally normative behavior, risk taking by adolescents may meet biological, psychosocial, or societal/parental needs, and as such the activity itself may be rewarding and reinforcing. Some problem at-risk behaviors among adolescents include substance abuse, sexual activity, and delinquent behaviors. Psychological symptoms accompanying such behaviors include loneliness, sadness, nervousness, tension, thoughts of hurting self, sleep difficulties, and interpersonal difficulties. Factors in risk taking are biology, parental influences, peer pressures, stressful events, and depression. Adolescent behaviors that are seriously antisocial or sociopathic may fit the delinquent syndrome described by Achenbach (1985) or conduct disorders identified by Kazdin (1987). For most adolescents whose behavior puts them at-risk for physical, social, or psychological harm, short-term crisis intervention suffices. For others, however, more intensive, long-term interventions are required. Although theory and research have not sufficiently progressed to provide a clear picture of proven interventions for at-risk adolescents, therapeutic techniques that develop coping mechanisms and social skills are important. 56 references.