[5-HT1A gene polymorphisms contributed to antidepressant response in major depression]

Variability in antidepressant response is due to genetic and environmental factors. Among genetic factors, the ones controlling for availability of the drug at the target site are interesting candidates. Rs6295C/G SNP in the 5-HT1A gene (HTR1A) has been found to affect the expression and function of HTR1A. In fact rs6295C/G is in strong linkage disequilibrium with other polymorphisms of HTR1A suggesting that those functional effects could be associated with polymorphisms other than or together with the synonymous rs6295C/G. In the present study we examined the possible association of a panel of markers in strong linkage disequilibrium of HTR1A with SSRI/SNRI response in 137 Japanese major depression subjects followed for 6 weeks. We observed a significant association of better response to antidepressant in rs10042486C/C (P < 0.0001), rs6295G/G (P < 0.0001) and rs1364043T/T (P = 0.018) genotype carriers, independently from clinical variables. Furthermore minor allele homozygous carriers in all these 3 SNPs were associated with treatment response by various assessments such as HAM-D score change over time (P = 0.001), week 2 (P < 0.0001), 4 (P = 0.007), and 6 (P = 0.048) as well as response rate (P = 0.0005) and remission rate (P = 0.004). We also pointed out the genotyping mis-definition of rs6295C/G in the previous four papers.