Epidemiological Issues in Measuring Preventive Effects

Depression, considered in all its myriad forms, is ubiquitous. Since antiquity depressive phenomena have been among humanity’s most common afflictions. Yet in spite of their common-place occurrence and deleterious effects on the human condition, we still know very little about the etiology of the wide spectrum of depressive disorders. This is not to say that we know nothing about depression. We know a good deal, much more than we did even a decade ago. But our knowledge is still fragmented and incomplete. It may be accurate to say that our current state of knowledge permits us, perhaps for the first time, to feel some confidence that we are beginning to understand depressive disorders.