Verbal working memory impairment in patients with current episode of unipolar major depressive disorder and in remission.

In this naturalistic cross-sectional study, the author tested the hypothesis that verbal working memory (WM) in major depressive disorder (MDD) persists even after remission. The subjects consisted of 54 adult clinic outpatients and 54 age- and sex-equated healthy comparison subjects. The author found that the digit sequencing task scores for verbal WM were significantly less in both patients with a current episode of MDD and patients in remission than in the controls. Also, there were no significant correlations between the digit sequencing task scores and the dose of antidepressants or benzodiazepines in patients experiencing remission. It is suggested that WM/central executive function in MDD might be impaired, and thus verbal WM might be, at least to a degree, trait related.