I’ve been up since 6 am. I’ve had a breath test for alcohol, a urine test for drugs and a psychological test for mental health. Then I’m handed a red pill and a glass of water. I swallow it… and I’m told to relax. Which is easier said than done when you don’t know if you’ve just taken vitamin C or 83 milligrams of pure MDMA.

I’m taking part in a groundbreaking study on MDMA, the drug commonly known as ecstasy. The research is run by David Nutt of Imperial College London, a former government adviser and one of the few UK researchers licensed to study class-A drugs.

His main aim is to discover what MDMA does to the human brain, something that, remarkably, has never been done before. A second goal is to study MDMA as a therapy for post-traumatic stress disorder. The experiment is also being filmed for a Channel 4 documentary called Drugs Live: The Ecstasy Trial, which will be broadcast in the UK next week.