Natural cannabis-like chemicals in the brain may help combat the leading genetic cause of autism.
Scientists linked blockages in a signalling pathway dependent on the chemicals, called 2-AG endocannabinoid transmitters, with symptoms of Fragile X syndrome, the most common known genetic cause of autism.
Correcting the fault with drugs led to dramatic behavioural improvements in mice with a version of Fragile X syndrome.
Boys are much more likely than girls to be born with Fragile X, which can cause mental impairment, learning difficulties, hyperactivity or impulsiveness. It can also lead to physical traits such as an elongated face, flat feet and large ears.
The study is the first to identify the link between the chemicals and Fragile X.