Subjective Cognitive Impairment in Major Depressive Disorder: Predictors and Clinical Outcomes

Aim: Individuals with subjective cognitive impairment (SCI) and major depressive disorder (MDD) are at high risk of developing neurodegenerative diseases. Studies suggest that SCI may be associated with concurrent cognitive performance and is also strongly associated with depressive symptoms. In this context, we aimed to evaluate the relationship between SCI and depression severity and to reveal predictive factors for SCI with current cognitive performance. Methods: Forty-two patients with MDD were divided into two groups: patients with and without SCI. All participants were administered the Montreal Cognitive Assessment (MoCA) and the Hamilton Depression Rating Scale (HAM-D). A logistic regression model was used to add demographic characteristics to the results obtained. Results: Individuals with SCI (n=21) were older (p=0.014) and less educated (p=0.006) than non-SCI patients (n=21) with MDD. Additionally, the mean of the MoCA total score was significantly higher in the non-SCI group (Student's t Test, p=0.011). Depression severity was the same throughout the groups (HAM-D, 𝜒2: 2.10, p= 0.28). Language dysfunction is one of the MoCA subtests, language impairment emerged as a key predictor in the binary logistic regression model, identified through Backward Wald elimination, for detecting depressive patients with SCI (p=0.007; OR=0.366; 95% CI 0.177-0.756). Conclusion: Our findings suggest that SCI accurately reflects concurrent cognitive performance in a clinic-based sample of MDD. The results also suggest that the clinical interpretation of SCI should take into account the possible impact of depression on the language domain.