Objective: Cognitive impairments have been identified as a core feature of major depressive disorder (MDD). To date, no studies on the association between education level and cognitive impairments of MDD from a Chinese population adopting the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) for cognitive measurement emerged. This study is the first to adopt the RBANS to examine whether cognitive impairments of MDD were influenced by education level in a Chinese population.
Methods: 90 patients with MDD and 90 healthy controls with matched gender and age were recruited in a case-control study. Cognitive functions were assessed using the RBANS. Moreover, the demographic and clinical data were collected from patients with MDD and healthy controls.
Results: There were significant differences in the RBANS total score (F=19.56, p<0.001), subscales of language (F=58.21, p<0.001) and delayed memory (F=7.72, p=0.006) between two groups after controlling for the variables. These differences still passed Bonferroni corrections (all, p<0.05). Education level of MDD was significantly correlated with the RBANS total score (r=0.277, p=0.010), language score (r=0.255, p=0.018) and delayed memory score (r=0.220, p=0.042). Stepwise multivariate regression analysis indicated that education level was an independent contributor to the RBANS total score (t=2.666, p=0.009), language score (t=3.644, p<0.001), and delayed memory score (t=3.312, p=0.001) of MDD.
Conclusions: Our findings supported that patients with MDD had poorer cognitive functions than healthy controls, especially in language and delayed memory. Moreover, education level could influence cognitive performance of MDD in a Chinese population.