Patients with major depressive disorder treated with escitalopram and assessed over 8 weeks.
Study results suggest that polymorphism in the serotonin transporter gene (5-HTTLPR) predicts escitalopram efficacy. Caucasians (labeled "self-identied whites" in the study) and Koreans have similar escitalopram response and remission rates when only s allele carriers are examined, but among l/l genotype carriers, a significant distinction is observable:
1. whites had greater Hamilton Depression Rating Scale-score reductions from baseline compared with Koreans among carriers of the l/l (Bonferroni P = 0.003)
2. White l/l genotype carriers had greater odds for response (odds ratio=48.0; 95% CI 3.70–622.0; Bonferroni P = 0.018) and remission (odds ratio=22.0; 95% CI 2.53–191.0; Bonferroni P = 0.030) compared with Korean l/l carriers.

N = 165 adult participants (47 white, 118 Korean), either inpatients or outpatients at the time of recruitment. Participants were self-identified as Koreans or whites, and ascertained by confirming the ethnicity of 3 generations of the participants’ families. Recruitement: Koreans (South) from one Korean site, Caucasians from two sites in Australia and Singapore.

(Bousman et al., 2014)


The 5-HTT gene-linked polymorphic-region (5-HTTLPR) polymorphism is associated with SSRI antidepressive effects. Han-Chinese patients (major depressive disorder) with the 5-HTTLPR l/l genotype had a significantly better response to fluoxetine when compared with s allele carriers, as evaluated on the basis of total (P = 0.013), core (P = 0.011), and psychic-anxiety (P = 0.005) and somatic-anxiety (P = 0.002) Hamilton Depression Rating Scale-score percentage change, confirming previous western reports.
(N= 121 patients with major depressive disorder; Han-Chinese sample population of Taiwan).
(Yu et al., 2002)