IMPORTANCEUnderstanding the epidemiologic profile of the life course of mental disorders is fundamental for research and planning for health care.Although previous studies have used population surveys, informative and complementary estimates can be derived from population-based registers.OBJECTIVE To derive comprehensive and precise estimates of the incidence rate of and lifetime risk for any mental disorder and a range of specific mental disorders. DESIGN, SETTING, AND PARTICIPANTSWe conducted a follow-up study of all Danish residents (5.6 million persons), to whom all treatment is provided by the government health care system without charge to the patient, from January 1, 2000, through December 31, 2012 (total follow-up, 59.5 million person-years).During the study period, 320 543 persons received first lifetime treatment in a psychiatric setting for any mental disorder; 489 006 persons were censored owing to death; and 69 987 persons were censored owing to emigration.Specific categories of mental disorders investigated included organic mental disorders, substance abuse disorders, schizophrenia, mood disorders,

A Comprehensive Nationwide Study of the Incidence Rate and Lifetime Risk for Treated Mental Disorders