Lorraine Robertson with her son, Max, 12, who is taking part in the Epidiolex trial, and Dr Richard Chin, his consultant

A drug extracted from cannabis plants is to be used to treat children with severe epilepsy at hospitals in Edinburgh, London and Liverpool.

Doctors are cautiously optimistic about “medical marijuana” following American trials of the drug Epidiolex. Studies showed a marked improvement in about 70 per cent of young patients who suffered multiple seizures, and for about 10 per cent their seizures stopped altogether. However, for another tenth the drug appeared to worsen their condition.

“The most impressive thing was the group who became completely seizure-free,” said Dr Richard Chin, director of the Muir Maxwell Epilepsy Centre in Edinburgh. “While we can’t rule out a placebo effect, it is encouraging that there were patients who went from daily events to being seizure-free. It would seem