Genomic DNA was extracted from circulating blood leucocytes by using Gentra Puregene Blood Kits according to the manufacturer’s protocol (Qiagen) and was stored at -20°C. The TRKB polymorphismswere genotyped by the IntegraGen company (Evry, France) using the Fluidigm®BioMarkTMHD system (Fluidigm Corporation, CA, USA), using TaqMan allelic discrimination (Coulbault et al., 2006), with the ABI Prism® 7900HT Sequence Detection System (Life Technologies).