Association of serum BDNF level and Val66Met polymorphism with response to treatment in patients of major depressive disease: A step towards personalized therapy

Background: Major depressive disorder (MDD) is one of the most common psychiatric disorders and only less than 50% of MDD patients achieve remission after the first antidepressant trial. Hence, it is important to understand the factors associated with response to various antidepressant medications. Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophin family. BDNF and Val66Met polymorphism in the BDNF gene has a role in MDD. This study aimed to determine the association of rs6265 polymorphism and serum BDNF level with response to treatment in MDD patients. Methods: The study included 200 subjects, consisting of 100 MDD patients treated with oral antidepressants and 50 treated with ECT, and 50 healthy controls. Serum BDNF levels were estimated using ELISA and rs6265 polymorphism was genotyped using tetra-primer ARMS PCR. Results: Val66Met polymorphism had an association with MDD, and in MDD patients with Met allele was associated with a better response to antidepressants. Serum BDNF level was significantly higher in MDD patients compared to healthy individuals. In MDD patients, lower serum BDNF level was associated with better ECT outcomes. Conclusions: Val66Met polymorphism in BDNF gene and serum BDNF level has the potential to be used as a biomarker for the prediction of response to oral antidepressants and ECT in MDD patients. The presence of the Met allele might be used to predict the chances of occurrence of MDD in the future. The results of our study might form a basis for the development of personalized treatment for MDD in the future.