The 5-HTTLPR and 13 additional markers across the serotonin transporter gene were genotyped in 795 adults with moderate-to-severe depression treated with escitalopram or nortriptyline in the Genome Based Therapeutic Drugs for Depression (GENDEP) project.
However, the MTR GG genotype exhibited a 5.750-fold increased risk of moderate and severe depression in postmenopausal women (95% CI=1.547-21.379, P=0.013).
Aberrant expression of the presynaptic serotonin 1A receptor (5-HT(1A)-R) because of a polymorphism in the 5-HT(1A)-R gene is associated with severe depression in human, whereas its absence up to postnatal day 21 (P21) in the forebrain of mice results in heightened anxiety in adulthood.