Abstract
Introduction Despite the ethnic differences in 5-HTTLPR (S
allele relates to better antidepressant response in Korean and Japanese people,
while L allele with better response in Caucasians), it is unclear whether
5-HTTLPR and its high expression locus rs25531 are
interactively associated with antidepressant treatment outcome. We investigated
the individual and interaction effects of these polymorphisms on antidepressant
treatment outcomes in the Korean population.
Methods A total of 464 Korean subjects with major depressive disorder
completed 6 weeks of antidepressant monotherapy. Venous blood was extracted for
genotyping 5-HTTLPR and rs25531 by polymerase chain reaction and
DNA sequencing. We used logistic regression analyses to verify the main and
interaction effects of 5-HTTLPR and rs25531 on response and
remission after antidepressant treatment.
Results After adjusting for covariates, the SS genotype of
5-HTTLPR was significantly associated with better treatment outcomes
(p<0.001, odds ratio [OR] [95% confidence interval
(CI)]=2.435 [1.551, 3.823] in response; p<0.001, OR [95%
CI]=2.912 [1.730, 4.903] in remission), while G-containing genotype
(AG+GG) of rs25531 was only associated with remission
(p=0.034, OR [95% CI]=2.104 [1.058, 4.181]). The
interaction effect of 5-HTTLPR and rs25531 on response and
remission was insignificant (all p>0.05).
Discussion Our findings suggest variations in allelic frequency and
functionality of 5-HTTLPR and rs25531 among the different
ethnicities. We found a minor advantage of rs25531 in achieving
remission. However, there was no interaction effect with 5-HTTLPR.
Key words
antidepressant treatment outcome - depression -
5-HTTLPR
-
rs25531
- Korean