Background: Bipolar disorder is a chronic brain disorder marked by periods of both manic and depressive episodes, distinguished by a normal period too. It can last a lifetime and may cause significant impairment. The prefrontal cortex, anterior cingulate cortex, hippocampus, and amygdala are the most pivotal parts of brain responsible for emotions regulation, responses, and behavioural response to stimuli. The BDNF rs6265, known as the Val66Met polymorphism, is associated with cognitive impairment in bipolar disorder patients leading to various changes in the structure of brain which is responsible for cognitive impairment. The present study focused on the determination of presence of Val66Met polymorphism in bipolar patients.

Methodology: The data and blood collection were done from the recruited 200 bipolar disorder cases and 200 age-sex matched controls with an informed-written consent from Punjab (India). The DNA was extracted with standard phenol-chloroform method, followed by the genotyping of rs6265 (PCR-RFLP) and statistical analysis was done.

Results: The differences were found to be statistically significant for the frequencies of genotypes and alleles, with p value ˂0.0001. The increased risk of developing BD was found to be associated with BDNF (rs6265) CT genotype (OR=2.47, p ˂0.0001) and TT genotype (OR=2.55, p=0.031) with statistically significant difference. The data revealed that the minor allele (T) supplemented the BD risk by 2.04 times (OR=2.04, 95%CI=1.45-2.86, p˂0.0001).