Multi-dimensional criteria for the diagnosis of depression.

The chief goal of the present study is to examine the validity of a dimensional approach to the classification of depressive disorders. Each of the the major diagnostic criteria for depression including symptoms, duration and frequency is examined with respect to a series of clinical validators. The sample is comprised of a cohort of 591 individuals from the total population of 18-19 year olds in Zurich, Switzerland who were followed for a period of 15 years. The results revealed that: (1) depression may be better represented on a continuum than as a discrete category; (2) there is a direct relationship between the number of symptoms of depression, the frequency and the duration of depressive episodes and indicators of validity of depression; and (3) in addition to the number of symptoms of depression, a combination of frequency and duration criteria enhance the validity of the classification of depression.