Cognitive deficits are associated with functional impairment in severely depressed patients

Cognitive deficits have been associated with poorer function and quality of life (QOL) in schizophrenia, but no similar findings have been confirmed in persons with major depressive episode (MDE). We investigated whether cognitive deficits were associated with detrimental effects on the QOL of persons with primary MDE. Seventy-seven non-demented adults with MDE underwent evaluations of mood, cognition and QOL. Cognition was assessed with the Mini-Mental State Exam, and delayed recall on the Rey Auditory Verbal Learning Task and the Rey Figure. QOL assessments included instrumental activities of daily living (IADL), activities of daily living (ADL), and satisfaction in role functioning and relationships. Univariate correlation and regression models were used to find those mood and cognitive variables most closely related to each QOL dimension. ADL function and satisfaction with role functioning and relationships were most closely related to depression severity and age. IADL functioning, however, was most closely associated with global cognition. This study did not take into account the physical health of the participants, and all the participants were seriously ill with depression. Thus, the results may not apply to persons with less severe MDE. Antidepressant treatments that preserve or enhance global cognition in addition to relieving core depressive symptoms may lead to the best functional outcomes.