This monograph presents an overview of adolescent health in the United States. Section 1 provides a brief introduction to the monograph. Section 2 presents one view of what constitutes adolescence and the threat to adolescent health, conceptualizing the latter to include health-compromising behaviors that put adolescents at risk for future problems as adults. Section 3 provides information on the major causes of adolescent mortality and morbidity, arguing that an increasing proportion of adolescent health needs is related to psychosocial and behavioral problems, rather than physical disease. Section 4 examines adolescent access to health care, concluding that adolescents face barriers to obtaining appropriate care that go beyond limitations in insurance coverage. Section 5 provides an assessment of programs aimed at preventing or curing mental disorders and high-risk behaviors. Section 6 describes research initiatives aimed at improving the ability to effect such preventions and cures. Section 6 also suggests mechanisms for the implementation and evaluation of effective health care services for adolescents. The initiatives suggested range from long-term research on both the common and unique antecedents of high-risk behavior among adolescents to the evaluation of prevention and intervention programs specifically designed for different age groups and different levels of risk for future harm. (Contains approximately 225 references.) (Author/NB)