Association Between The 5-HTTLPR Polymorphism and Response to Citalopram in Turkish Patients With Major Depressive Disorder

The objective of this study was to investigate the relationship between the genetic polymorphism of the serotonin transporter gene-linked polymorphic region (5-HTTLPR)and the response to citalopram treatment and side effects in Turkish patients with major depressive disorder. The study involved 51 patients who received 10-40 mg/day of citalopram for 4 to 6 weeks. Clinical symptoms were evaluated by the 17-item Hamilton Depression Rating (HAMD-17) scale, Clinical Global Impression (CGI) and UKU side effect rating scale (UKU) at weeks 4 and/or 6. The 5-HTTLPRL/S polymorphism was determined by slowdown-polymerase chain reaction method. Of the fifty-one patients, 13 (26%) were the LL genotype, 21 (41%) were the LS genotype, 17 (33%) were the SS genotype. L allele seems to be associated withbetter response due to odds ratio for L allele versus S allele despite statistically insignificant. In terms of CGI-Severity scale, The LL genotype versus the LS genotype had a higher risk at the week 6 (P<0.05).On the other hand, apart from this comparison, there is no significant difference in CGI-Severity and Improvement and UKU scales according to the distribution of genotypes at week 4 and/or 6. However, these findings surely need further investigation and confirmation.