[Melancholia and depression--from madness to illness].

In present time depression affects 3-5% of the population in the western countries. Has this illness always existed? Can it be traced backwards in historical periods? The answer is a reluctant yes. The term "depression" has been in use in psychiatry for only 150 years and the very term "psychiatry" for 200 years. Before 1800, in classical times, only few elements of modern depression were part of the concept of "melancholia". Classical melancholia was a madness of the few, presenting with "psychotic" symptoms according to present terminology. The depression of modern man is a much broader concept including elements of well-being and capacity to work. Thus, although psychotic symptoms seem to connect the terms melancholia and depression, scientific, social and cultural developments separate the two. This is yet a testimony to the fact that concepts of illness and diseases changes rapidly and distinctively over historical periods.