The Impact of the CYP2D6 and CYP1A2 Gene Polymorphisms on Response to Duloxetine in Patients with Major Depression

Depression is a global mental health concern, and personalized treatment approaches are needed to optimize its management. This study aimed to investigate the influence of the CYP2D6 and CYP1A2 gene polymorphisms on the efficacy of duloxetine in reducing depressive and anxiety symptoms. A sample of 100 outpatients with major depression, who initiated monotherapy with duloxetine, were followed up. Polymorphisms in the CYP2D6 and CYP1A2 genes were assessed. The severity of depressive and anxiety symptoms was recorded using standardized scales. Adverse drug reactions (ADRs) were analyzed. Statistical analyses, including linear regression, were conducted to examine the relationships between genetic polymorphisms, clinical variables, and treatment outcomes. Patients with higher values of the duloxetine metabolic index (DMI) for CYP2D6, indicating a faster metabolism, achieved a greater reduction in anxiety symptoms. The occurrence of ADRs was associated with a lower reduction in anxiety symptoms. However, no significant associations were found between studied gene polymorphisms and reduction in depressive symptoms. No significant effects of the DMI for CYP1A2 were found. Patients with a slower metabolism may experience less benefit from duloxetine therapy in terms of anxiety symptom reduction. Personalizing treatment based on the CYP2D6 and CYP1A2 gene polymorphisms can enhance the effectiveness of antidepressant therapy and improve patient outcomes.