HTR1A and major depressive disorder: 5-HT1A receptor genotype distribution at SNP rs6295 did not differ between the MDD and control groups (χ2 = 2.55, d.f. = 2, P = 0.2788) or between those with and without reported childhood adversity in the MDD group (χ2 = 3.59, d.f. = 2, P = 0.1665).