Association Between GRIN1 rs28489906 and Major Depressive Disorder and Treatment Response to Antidepressants in...

Major depressive disorder (MDD) is a common comorbidity of type 2 diabetes (T2D) with low rates of treatment response to antidepressants. The pathophysiology of these conditions overlaps in N-methyl-d-aspartate receptors (NMDARs), which are present in neurons and pancreatic cells. GRIN1 encodes NMDARs and has been associated with depression and T2D; however, its role in the coexistence of MDD and T2D and the treatment response to antidepressants has yet to be explored.

We aimed to evaluate the association between GRIN1 rs28489906 and MDD and treatment response to antidepressants in patients with T2D.

A prospective study was conducted on T2D patients enrolled in a comprehensive care program with follow-up at 3 months. Subjects were assessed for MDD, and genotyping for GRIN1 rs28489906 was performed. Depression scores and glycated hemoglobin (HbA1c) were analyzed using the Wilcoxon paired signed-rank test, and a stratified analysis was conducted to assess treatment response. Logistic regression analyses were performed to predict MDD and treatment response.

Our sample included 232 patients; among them, 49 (21%) had MDD. Patients with MDD showed a higher frequency of the AA genotype compared with non-MDD subjects (p = 0.026). A allele carriers reported lower treatment response rates (p = 0.049) and decreased odds of treatment response (OR = 0.03, 95% CI 0.002-0.63, p = 0.023). Patients with AG and AA genotypes with treatment response exhibited lower HbA1c (p = 0.029).

The A allele of GRIN1 rs28489906 was associated with MDD and treatment response in patients with T2D. Our findings highlight the role of glutamate in these comorbidities and the need for different therapeutic approaches based on genetics.