Cognitive functioning in depression: a review of theory and research

This paper reviews recent research into cognitive functioning in depression, with particular reference to the theories of Lewinsohn, Beck, Seligman and Klein. The major cognitive changes in depression are a decrease in the ability to maintain concentration and effort, and an increase in the relative salience of aversive events and memories, with a corresponding decrease in the salience of pleasant events. There is as yet little evidence to support the view that depressions arise out of pre-existing depressive attitudes. Attention is drawn to the heterogeneity of depressive disorders, and the significance of the endogenous/non-endogenous distinction is discussed.