AGES OF ONSET OF PSYCHIATRIC-DISORDERS IN A COMMUNITY POPULATION OF OLDER ADOLESCENTS

Objective: Ages of onset of psychiatric disorders, as well as the link between early onset and later psychosocial functioning, were examined in a community population of older adolescents. Method: Subjects were 386 adolescents who were participants in an ongoing 14-year longitudi nal study. At age 18, lifetime diagnoses and ages of onset of major de pression, phobias, post-traumatic stress disorder, and substance disor ders were assessed using the NIMH Diagnostic Interview Schedule, Revis ed Version. Behavioral, emotional, and academic functioning in later a dolescence were evaluated through self-report measures and school reco rds. Results: Almost one fourth of the adolescents met criteria for at least one disorder by age 14. Simple phobias emerged earliest (by ear ly childhood), whereas for major depression and substance disorders th e peak risk periods for onset were midadolescence. The early onset (by age 14) of disorders was associated with continued impairments in beh avioral and emotional functioning in late adolescence (at age 18). Fur thermore, the early onset of disorders, compared to later onset (ages 15 through 18), increased the risk for additional co-occurring disorde rs. Conclusions: The striking levels of early psychopathology and asso ciated long-term deficits in functioning found in this community popul ation underscore the need for programs of early intervention.