MiR-34a rs2666433 and cognitive function in major depressive disorder: a clinical correlation analysis

Genetic factors play a crucial role in the development of major depressive disorder (MDD).

This study aimed to investigate the association between the microRNA (miR)-34a rs266643 polymorphism and MDD, as well as its impact on cognitive function.

Clinical data and blood samples were collected from 302 MDD patients and 306 healthy controls who met the predefined inclusion and exclusion criteria. The severity of MDD in patients was assessed using the Hamilton Rating Scale for Depression (HRSD). Cognitive function in MDD patients was evaluated using the Mini-Mental State Examination (MMSE), Stroop Color-Word Test (Stroop-C and Stroop-CW), and Montreal Cognitive Assessment (MoCA). Gene typing was performed using the Sanger sequencing method, while the relative expression level of miR-34a was quantified by RT-qPCR.

The MDD group exhibited a significantly higher miR-34a expression fold change compared to the control group (p < 0.001). Among the genotypes, the AA genotype demonstrated the highest expression, followed by GA, with both being significantly greater than GG. The expression of miR-34a was positively correlated with HRSD, Stroop-C, and Stroop-CW scores but negatively correlated with MMSE and MoCA scores (p < 0.001). Carrying the A allele (OR = 1.468, p = 0.002) or the AA genotype (OR = 2.382, p = 0.001) was associated with an increased risk of MDD. Furthermore, patients with the AA genotype exhibited significantly poorer cognitive function compared to other genotypes.

The gene polymorphism of miR-34a rs2666433 was significantly associated with the severity of MDD as well as cognitive function.