To determine 5-HTTLPR genotype, DNA was extracted from venous blood using the technique described in Gustincich et al. [38] and then amplified with polymerase chain reaction (PCR). The forward primer used was 5′-GGC GTT GCC GCT CTG AAT GCC A-3′, while the reverse primer was 5′-GAG GGA CTG AGC TGG ACA ACC AC-3′. PCR was performed in a total volume of 20.4μL containing 2.0 μL dNTP mix(2.5mM), 2.0 μL Taq buffer, 0.4 μL of the Taq polymerase Enzyme(5 Units), 12.0 μL DEPC H2O, 2.0 μL of the primer mix and 2.0 μL of the genomic DNA (approximately 150 ng). Cycling conditions consisted of 1) a 10 min denaturation at 95°C, 2) 45 cycles of 30 sec denaturation at 95°C, 3) 30 sec annealing at 65°C, 4) 60 sec extension at 75°C, and 5) a final cycle of 75°C for 5 min. The PCR products were separated by electrophoresis in a 2% agarose gel prepared with ethidium bromide. Three allele variants of the gene polymorphism were identified based on the PCR fragment sizes: short (S; 486bp, 14 repeats), long (L; 529bp,
