The result of BDNF (brain derived neurotrophic factor) locus on chromosome 11 was consistent with prior studies that had shown strong associations of this locus with BMI [18,39] and various smoking phenotypes.[17] Evidence from epidemiological studies [40] and animal studies [41] also indicate associations of BDNF gene with other substance abuse related disorders, eating disorders, and schizophrenia. Here, BDNF is linked to schizophrenia.