Does gender influence cognitive function in non-psychotic depression?

Cognitive impairment is a core feature of major depressive disorder (MDD). Although sex differences in several aspects of MMD have been established, previous findings are insufficient in determining whether sex differences exist in cognitive function. We investigated this topic in 130 medicated inpatients with current MDD without psychotic features (DSM-5 criteria) who were hospitalized to attend a 4-week psychiatric rehabilitation program. All variables analyzed were obtained from the patients' electronic medical records and recorded during hospitalization in accordance with standardized procedures. We considered clinical and neuropsychological variables collected within the first 3 days of hospital admission before any pharmacological modification and the beginning of the rehabilitation program. The standardized neuropsychological battery assessed verbal memory (Babcock Story Recall Test), language fluency (phonemic/semantic fluency test), verbal working memory (Digit Span backward), and psychomotor speed (Trail Making Test, Part A). As a whole, our sample significantly underperformed in comparison to Italian normative samples in all neuropsychological measures except for psychomotor speed. Controlling for potential confounding effects (illness severity/current smoking/medications), a general linear model revealed that compared with men, women significantly underperformed in all tests except for phonemic fluency. Our preliminary results indicate that women with non-psychotic MDD may be more susceptible than men to the detrimental cognitive effects of depression at least for some cognitive variables. If confirmed, this finding suggests that sex-dependent cognitive differences should be considered when tailoring therapeutic interventions in MDD.