Features of cognitive impairment and related risk factors in patients with major depressive disorder: A case-control study

Background: Cognitive impairment (CI) is a common symptom contributing to functional loss in major depressive disorder (MDD). However, the features of CI and its related risk factors in young and middle-aged MDD patients remain unclear. Methods: In this case-control study, 18- to 55-year-old acute-onset MDD patients and healthy controls (HCs) were recruited from nine centers in China. MDD patients were diagnosed based on the DSM-IV, the Mini-International Neuropsychiatric Interview, and a 17-item Hamilton Rating Scale for Depression score >= 14. Cognitive function, including attention/vigilance, learning, memory, processing speed and executive function, was assessed with a neuropsychological battery and compared between MDD patients and HCs. MDD patients scoring 1.5 SDs below the mean HC score in at least 2 domains were defined as having CI. Logistic regression analysis was used to identify risk factors for CI in MDD patients. Results: Compared with HCs (n = 302), MDD patients (n = 631) showed significant impairment in all cognitive domains (P < 0.001); 168 MDD patients (26.6%) had CI. Male sex (OR: 1.712; 95% CI: 1.165-2.514; P < 0.01) was positively correlated with CI; age of first onset (OR: 0.974; 95% CI: 0.957-0.991; P < 0.05) and comorbid anxiety disorders (OR: 0.514; 95% CI: 0.332-0.797; P < 0.01) were negatively correlated with CI. Limitations: Biomarkers and neuroimaging were not used to investigate the possible biological mechanism and neural basis of CI in MDD. Conclusions: CI was prominent in adults with acute-onset MDD; male sex and younger age of first onset were independent risk factors, and comorbid anxiety disorders were a protective factor.

Automated summary

This study found that cognitive impairment is common in patients with major depressive disorder, and it is associated with male sex and younger age of first onset, while comorbid anxiety disorders are protective against cognitive impairment.