David Nutt , Edmond J Safra professor of neuropsychopharmacology Imperial College London, London W12 0NN, UK d.nutt{at}imperial.ac.uk

Cannabis has been used as a medicine for millennia, writes David Nutt, who charts its relatively recent prohibition, the effect on patients such as Billy Caldwell, and the failure of legal reform to make much difference

Cannabis is arguably the world’s oldest medicine, with evidence of such use from 3000 year old tombs in Egypt and Siberia. It had a place in Indian and Chinese medical writing from nearly as long ago. It didn’t enter the UK until the late 1600s, but by the 1800s it was widely used, sold over the counter as an alcoholic tincture for problems such as tetanus and seizures. Its efficacy more broadly became apparent, and the definitive overview was published in the Lancet in 1890 by John Russell Reynolds.1 Because he was the Queen’s physician it is believed that Queen Victoria used cannabis medicines, particularly for period and childbirth pains.

The demise of cannabis as a medicine began rather surprisingly when in 1933 the US Senate voted to rescind the law on alcohol prohibition. This left the threat that 35 000 officers of alcohol prohibition enforcement (now the Drug Enforcement Administration) would lose their jobs, along with their director, Harry Anslinger.2 So Anslinger created a new drug scare in alcohol’s place: cannabis.

He used its Mexican name, marijuana, to associate its use with unofficial immigrants. Then, working with the less scrupulous media, he created scare stories about the damage wrought by cannabis: that its use would destroy Americans’ lives and result in white women being raped by drug crazed foreigners, and so on. Though fanciful and dishonest, these stories created the intended public moral panic.