While the efficacy of subchronic CBDV treatment at adulthood was limited to acoustic startle and at the lowest dose (Study 1), chronic administration of both doses of CBDV from weaning (Study 2) eliminated all the behavioral alterations of Fmr1-KO mice, except hyperactivity and reduced anxiety, thus preventing the most relevant symptoms associated with the FXS. The gene discussed is FMR1; the disease is fragile X syndrome.