DBH and major depressive disorder: There was significant correlation between presence of rs1800955 in DRD4 (P = 0.001) and rs25531 in 5-HTT (P = 0.003) with higher depression scale in group B. Also significant correlation was detected between presence of rs25531 in 5-HTT (P = 0.002), rs1800955 in DRD4 (P = 0.001) and rs1611115 in DBH (P = 0.004) with higher HDRS-17 scale in group D.