Those results were confirmed by the regression analyses that highlighted AdAS spectrum total score as a negative predictor of platelet BDNF levels, implying that more severe pathology is related to greater alterations in BDNF levels and that, among the other dimensions included as independent variables (social anxiety, suicidality, and trauma- and stress-related symptoms) the autism spectrum dimension was indeed the one most linked to BDNF. This evidence concerns the gene BDNF and autism.