Objective: To investigate how first incidence of various mental disorders changed between the periods of 1947-1972 to 1972-1997 in the Lundby cohort.
Method: First-incidence rates of mental disorders were calculated for two 25 year periods and ten 5 year periods.
Results: From 1947-1972 to 1972-1997 a decrease in almost all age- and sex-specific incidences of neurotic and organic brain disorders was observed, whereas incidence rates of psychotic disorders increased consistently in male subjects but decreased in most age intervals in female subjects. For both sexes the age-standardized 5 year period incidences of neurotic disorders decreased after 1972, fluctuated for psychotic disorders 1947-1997 and decreased steadily for organic disorders 1947-1997.
Conclusions: The reduction in neurotic and organic brain disorder incidences may be linked to structural changes in society and medical advances.