“Fragile X Syndrome is a neurodevelopmental disorder which affects intellectual, social and physical development due to mutation of the Fragile X mental retardation 1 (FMR1) gene. The resultant loss of Fragile X mental retardation protein can be modelled by Fmr1 gene knockout (KO) in mice.

The current study investigated the behavioural effects of cannabidiol (CBD; a non-psychoactive phytocannabinoid) in male Fmr1 KO mice as a preclinical model for therapeutic discovery.

Overall, acute CBD at the doses chosen did not selectively normalize behavioural abnormalities in Fmr1 KO mice, but reduced anxiety-like behaviour in both Fmr1 KO and WT mice.” https://www.ncbi.nlm.nih.gov/pubmed/31063743

“Acute cannabidiol (CBD) decreased anxiety-related behaviours in both Fmr1 knockout mice and wildtype controls in the elevated plus maze. Fmr1 KO mice were hyperlocomotive, showed fewer anxiety-related behaviours and habituated more slowly to a novel environment than controls. Acute CBD had no impact on locomotion, spatial working memory or fear-associated memory in Fmr1 knockout mice or controls.”   https://www.sciencedirect.com/science/article/pii/S0091305718306464?via%3Dihub