Subscribe to BBC News www.youtube.com/bbcnews
Parents in the US with severely epileptic children are turning to marijuana for treatment.
Oil produced from a strain of the plant, which doesn't make the children high, appears to be having a dramatic effect on reducing seizures. It's being produced in Colorado, one of the two US states which has legalised cannabis.
Although not scientifically proven, families think it's making a big difference - and a British pharmaceutical company is trialling a new epilepsy drug based on cannabis extract, which has been approved by the US Federal Drug Administration.