MAOA gene polymorphisms and response to mirtazapine in major depression

Background Polymorphisms in the monoamine oxidase A (MAOA) gene may influence treatment outcomes in major depression disorder (MDD). Objective To investigate the association of MAOA genetic polymorphisms and response to mirtazapine in patients with MDD. Method Fifty‐eight adult patients in Taiwan who met the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM‐IV) diagnostic criteria for MDD were given mirtazapine for 7 weeks and evaluated on days 0, 7, 14, 21, 49 using the 24‐item Hamilton Rating Scale for Depression (HRSD). Remission was defined as a final HRSD ≤ 10 and a 50% reduction in baseline HRSD score. Patients provided venous blood for DNA testing. The patients' response to mirtazapine treatment was compared between those who had the long‐form polymorphism in the MAOA gene promoter and the short‐form polymorphism. Result The total HRSD scores after mirtazapine treatment were significantly lower than baseline (p