Incidence data are presented for the 7 most frequent specific categories of mental disorder available in the NIMH Epidemiologic Catchment Area (ECA) program (major depressive disorder; panic disorder; phobic disorder; obsessive-compulsive disorder; drug abuse/dependence; alcohol abuse/dependence; cognitive impairment). The DSM-III case definitions in the ECA Program are according to the implementation of the Diagnostic Interview Schedule (DIS). Rates of incidence are presented specific for age, sex, and site, and pooled smoothed curves for the relationship of age to incidence, specific for sex are shown. The 7 disorders have distinctly different relationships to sex and age of onset.