The purpose of this study is to determine the individual contribution, or i
mportance number, of the symptoms to an analysis of depression, utilizing a
neural network model. In addition, the presence of hopelessness and somati
c complaints was examined, to determine their relevance to depression. Usin
g Wave 1 data from Duke University's contribution in the Epidemiological Ca
tchment Area (ECA) study, we created a mathematical model, a neural network
, to map the relationship of nine symptoms of major depression, hopelessnes
s and somatic complaints to the presence or absence of the formal diagnosis
of depression, and performed a contribution analysis. The contribution ana
lysis using the neural network revealed that the symptoms with the greatest
impact on the occurrence of depression, or with the largest importance num
ber for depression, were sadness, loss of interest, tiredness and sleeping
trouble, in that order. The most frequently reported symptoms, though, were
sadness, sleeping trouble, suicidal ideation, tiredness and poor concentra
tion, in that order. Hopelessness and somatic symptoms were the lowest in t
heir contribution to the diagnosis of depression. The study thus provides t
he hierarchy of the symptoms of depression and supports the DSM classificat
ion of major depression. (C) 1999 Elsevier Science Ireland Ltd. All rights
reserved.