At an extraordinary moment in the history of one of the world’s oldest and most controversial drugs, Horizon investigates the very latest medical and scientific research into the effects of cannabis on the brain and the body.
Medicinal cannabis became legal in the UK on 1 November 2018, but it is still shrouded in controversy. A&E doctor Javid Abdelmoneim wants to find out whether it will help or harm patients.
In the UK Javid encounters the first British patient to be prescribed intoxicating herbal cannabis to treat her chronic condition. He meets psychiatrists at King’s College London who reveal their new study linking cannabis more strongly than ever to alarming mental health problems. And he takes part in a groundbreaking trial looking at the effects of the different chemicals in cannabis on the brain.