The annual incidence of mental disorders in a Finnish cohort was approximately 15 per 1000 over a 16-year follow-up period.
BACKGROUND: The aim was to give estimates of the incidence of different mental disorders from a Finnish prospective epidemiological follow-up study, the UKKI Study. METHOD: The original probability sample consisted of 1000 persons, aged 15-64 years. The baseline survey took place in 1969-71, and follow-up surveys were conducted 5 and 16 years after the baseline survey. The research methods included a personal psychiatric interview and data collection from different registers. The diagnostic system was based on the ICD-8 classification. RESULTS: The estimated annual incidence of all mental disorders was close to 15 per 1000 both between baseline and the 5-year follow-up as well as between the 5-year and the 16-year follow-up. During the entire 16-year follow-up period the annual incidence of all disorders was 14 per 1000 in men and 17 per 1000 in women. The annual income of neurotic disorders was 10 per 1000 in men and 14 per 1000 in women, and that of psychotic disorders 2 per 1000. CONCLUSIONS: In the literature, there are huge differences in the results concerning incidence of mental disorders. The results of the present study were rather close to those of the Swedish Lundby Study, but nowhere near the results of the American ECA Study.
Lehtinen et al. (Sat,) studied this question.