An Israeli mother who gave her autistic son cannabis to alleviate his symptoms is in London next week to share her story and raise funds for clinical trials of the drug.

Abigail Dar has told of how cannabis hugely improved the quality of life for her 23-year old son Yuval, who is severely autistic and epileptic. “He was hostile, stressed out and violent,” she said. “Public outings would often be traumatic as Yuval would unexpectedly break into aggressive outbursts.”

Eighteen months ago she gave Yuval cannabis, because while anti-psychotic medication is prescribed to alleviate behavioural issues, but many patients – Yuval included – suffer “devastating side-effects” and “years of agony” as a result.

Medical cannabis is already prescribed for certain illnesses in Israel, but not yet for autism. However, Abigail heard that cannabis could help, and said she noticed a “dramatic difference” immediately, with Yuval becoming “more relaxed and smiley,” adding that he “started to interact non-verbally with family members”.

Now, together with fellow mothers Sharon Imberman and Mieko Herster-Perez, she has launched a crowd-sourcing drive to establish a global information centre for the safe and effective treatment of medical cannabis for autism.

The trio, who have so far raised more than $10,000, are working with Professor Dedi Meiri and his data-gathering project at the Laboratory of Cancer Biology and Cannabinoid Research at Technion.

He has already started gathering data and tracking over 70 Israeli children and adults being treated with medical cannabis, and the money will expand this research, understanding which cannabis strains are most effective in treatment, and why.