Cognitive function in unipolar major depression: a comparison of currently depressed, previously depressed, and never depressed individuals.

There is a lack of consensus upon a conclusive cognitive profile characterizing unipolar major depression. Currently depressed (n = 37), recovered previously depressed (n = 81), and never depressed controls (n = 50) underwent assessment of executive functions, working memory, attention, and psychomotor speed. Currently depressed yielded significantly lower test scores than previously and never depressed subjects on a measure of working memory. Both currently depressed and previously depressed scored significantly lower than never depressed subjects on measures of processing speed. Recurrent depressed performed similarly to subjects with a single depressive episode. These findings indicate a mild and limited cognitive impairment during the course of a mild to moderate major depressive disorder among relatively young adults. Impaired processing speed should be considered in further studies as a potential irreversible marker for recurrent depression.