THE CENTRAL objective of this paper is to examine the contributions that epidemiological studies of psychiatric disorders have made to our knowledge about these disorders. Here, I have viewed these studies as a contribution to medical ecology as well as to the larger, general area that has been gradually emerging as social psychiatry. In order to place the review of these epidemiological studies in proper perspective it is essential to (1) explore the various conceptions that have been held concerning the nature of human ecology; (2) show the relationship between the broad field of human ecology and medical ecology; (3) point to the distinguishing characteristics between epidemiology and medical ecology; and (4) examine the obstacles that confront any investigator who studies mental illness from an epidemiological perspective.
The term ecology has had an erratic development and also an erratic use, particularly when trying to encompass human life. The term