In order to estimate the prevalence of affective disorders in Hungary a sample of the Hungarian adult population (18-64 years) selected at random was interviewed using the Diagnostic Interview Schedule (DIS) which generated DSM-III-R diagnoses. The lifetime rate for Major Depressive Disorder (MDD) was 15.1%, and for Bipolar Disorders (BD) 5.1%. The female-to-male ratio was 2.7 for MDD and nearly equal for BD. The 1-year and 1-month period prevalence rates were 7.1% and 2.6% for MDD and 0.9% and 0.5% for manic episodes. A higher rate of divorced or separated persons was found among individuals with a lifetime diagnosis of MDD. Besides these, the lifetime diagnosis of BD coexisted with higher rates of the never-married state. The highest hazard rate for the development of BD or MDD was in the range 15-19 years but in MDD another peak was also found in the range 45-50 years. The first peak was characteristic of the recurrent, and the other one of the single form of MDD. Insomnia, loss of energy, decreased interest, concentration problems were the most common symptoms during the depressive episode, independent of polarity. Higher rates of lifetime diagnosis of dysthymia and all kinds of anxiety disorder were revealed among persons with MDD. BD was associated with GAD (Generalized Anxiety Disorder), and panic disorder more often than chance.