Neurocognitive impairment in drug-free patients with major depressive disorder

TLDR

Neurocognitive impairment is widely reported in major depressive disorder, but studies rarely control for confounding factors such as psychotropic medication effects. This study aimed to assess neurocognitive function in medication‑free patients with MDD compared to healthy controls. Forty‑four DSM‑IV diagnosed, medication‑free MDD patients and 44 demographically matched healthy controls completed a comprehensive neurocognitive battery. Medication‑free MDD patients showed significant deficits in attention, executive function, and visuospatial learning and memory relative to controls, while motor and psychomotor functions remained intact, and impairment severity correlated with learning and memory but not executive function, indicating pronounced neurocognitive dysfunction independent of medication effects that may serve as an objective brain‑function marker.

Abstract

Background Although neurocognitive impairment has been widely reported in major depressive disorder (MDD), confounding factors, such as the effects of psychotropic medication, have rarely been controlled for. Aims To examine neurocognitive function in medication-free patients with MDD and healthy controls. Method Forty-four patients meeting DSM–IV criteria for MDD, all psychotropic-medication-free for at least 6 weeks, and 44 demographically matched, healthy comparison subjects completed a comprehensive neurocognitive battery. Results Patients with depression were impaired significantly in a range of cognitive domains, including attention and executive function and visuospatial learning and memory, compared with controls. Motor and psychomotor functions were intact. Severity of depression correlated with learning and memory performance, but not executive function. Conclusions Pronounced neurocognitive impairment was found in this sample of young adult out-patients with MDD. This is not attributable to the confounding effects of psychotropic medication and could therefore provide an objective marker of brain dysfunction in depression.