We present estimates of lifetime risk and of cumulative risk up to each age for depressive disorder for the population of an inner city area (Camberwell, SE London). Estimates are based on an incidence study for the year 1976 which drew from the records of a case register. The estimates of lifetime risk obtained, 12% for men and 20% for women, are similar to those previously published in the literature. Inception risk by age and risks for in-patient treatment are also presented for men and women. The method of calculation is discussed and we show how to obtain an upper limit for the effect of the increased mortality associated with the disorder. We noted an apparent decline over the 'seventies' in inception rates for depression, and we consider the comparability of our statistics with risks calculated using complete psychiatric history data.