In what will be the first study of its kind, an Israeli medical centre is to investigate whether some of autism's effects can be reduced by the use of medical marijuana.

The Shaare Zedek Medical Center in Jerusalem will test the effects of marijuana on 120 people aged between four and 30 who are classed as low-to-medium functioning as they are on the autism spectrum.

Relatives of autistic children have long claimed that cannabis helps calm their child down, making them less stressed and less likely to hurt themselves.

Now, after undertaking some preliminary research, the Shaare Zedek is to launch the first study of its kind in the world involving the administration of liquid drops and the use of placebos.

"Our waiting lists are full," said Dr. Adi Eran, who will lead the study and has applied for permits from the health ministry. "Many, many families want to participate and they come from all over Israel. They hope and they heard from their friends and other families that it might help."

Specialists at the clinic are helped by the fact that Israel has a relatively tolerant view towards marijuana. There are over 27,000 medical marijuana patients in Israel.

The health ministry has a medical cannabis unit which is also investigating how the drug could alleviate Parkinson's disease, Tourette's and insomnia, Forward reports. Israel is also poised to sell marijuana to US states where the drug has been legalised or decriminalised.

There have been cases in other countries where children with autism have seen improvements on their condition after being given marijuana. However doctors in Israel stress that the drug is not a "cure" for the condition and can only alleviate some of its effects.

 A worker harvests cannabis plants
A worker harvests cannabis plants at a medical marijuana plantation near the northern town of Nazareth, Israel . REUTERS/Amir Cohen