The incidences of major psychiatric syndromes (DSM III-R, axis I) in the age group 18–49 years were investigated. Incidence was defined as first ever admission rates during a period of 1 year.. The study base was a well-defined catchment area of 217,649 persons. Selection bias was analyzed by the use of a population-based psychiatric case register. Information bias was minimized by the use of a semi-structured interview, the Present State Examination, 10th edition. Comorbidity defined as significant cooccurrence of Axis I disorders was analyzed by multivariate statistics. One hundred and sixty-six patients were interviewed. PSE-10, now published by WHO, proved to be as reliable as its predecessors, and appropriate for the severely ill psychiatric patient. Incidences of schizophrenia, other psychoses stratified for the presence of psychoactive substance use disorders, and mood disorders stratified for anxiety disorders were reported. The sample was biased towards younger individuals with more severe psychopathology.
