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.

The BBC's Alastair Leithead reports.

Filmed and edited by the BBC's Luke Winsbury

Altered States is a series of video features published every Wednesday on the BBC News website which examine how shifting demographics and economic conditions affect America on a local level.