The NCS- A was designed to: estimate the lifetimc-to-date and current prevalence, age-of-onset distributions, course, and comorbidity of DSM-IV disorders in the child and adolescent, years of life among adolescents in the US; identify risk and protective factors for the onset and persistence of these disorders; describe patterns and correlates of service use for these disorders; and lay the groundwork for subsequent follow-up studies that can be used to identify early expressions of adult mental disorders. Forthcoming results of these two national surveys of adolescent mental health in the US, the National Comorbidity Survey-Adolescent Extension (http://www.hcp.med.harvard.edu/ncs/) and the National Health and Nutrition Examination Survey (NHANES) (http://www.cdc.gov/ nchs/nhanes.htm) should begin to address the gap in knowledge regarding the epidemiology of adolescent mood disorders in the US.
