We examined the prevalence of depressive disorders and associated factors in the general population in Finland using the Computer-Assisted Telephone Interview (CATI) method. A total of 2293 (71%) of 3250 individuals randomly drawn from the population registry and representing the adult population of Finland in the age group 25-79 years were interviewed by telephone in autumn 1994. The interview included a short form of the University of Michigan version of the Composite International Diagnostic Interview (UM-CIDI) generating probability diagnoses of DSM-III-R major depressive episode and dysthymia. The age-adjusted 6-month prevalence was 4.1% for major depressive episode and 1.7% for current dysthymia; depressive mood during the preceding month was reported in 17% of cases. Major depressive episodes and depressive mood were significantly more prevalent among females than males. In the logistic regression analyses, factors associated with the depressive disorders were found to vary somewhat depending on sex and type of disorder. Only about 50% of those with major depressive episode or dysthymia reported a self-perceived need for mental health services.