Indeed, a recent systematic review of the literature on the differences in baseline levels of BDNF and a Val66Met polymorphism of BDNF in bipolar disorder and schizophrenia among responders and non-responders presents that higher levels of baseline BDNF and the BDNF Val/Val genotype may be present in responders to both pharmacological and non-pharmacological treatments [62]. This evidence concerns the gene BDNF and schizophrenia.