The recent interest in childhood depression has exacerbated the confusion about nosology of this disorder. An attempt was made to synthesize the latest theories of several groups working in this area. A point-by-point comparison between the diagnostic criteria of Cytryn and McKnew, Weinberg, Kovac''s CDI [Children Diagnostic Inventory] and DSM-III [Diagnostic and Statistical Manual of Mental Disorders] was presented. There is a striking overlap between these criteria with minor exceptions. Apparently childhood and adult diagnostic criteria for affective disorders are very similar, and DSM-III is a valid instrument for diagnosing childhood affective disorder.