In late 2009, the psychiatrist Friederike Meckel was arrested in Zurich and charged with multiple violations of the Swiss Narcotics Act. Meckel didn’t dispute the charges. She admitted that she and her husband, a lawyer, hosted group therapy sessions at their mountain villa, where therapist and patients – including doctors, academics and lawyers – took MDMA and LSD. The group was undone by an ex-patient, a woman who brought her husband to the sessions to work on their marital problems. He left her and moved in with Meckel and her husband; she told the police about the drugs.

As the Swiss papers crowded in for a ‘rich people behaving badly’ story, Meckel deployed a simple counter-argument in court: the drugs were administered safely; the therapy was effective; she wasn’t a dealer but a healer. She was given a suspended sentence and a small fine. She also had to give up her medical licence, but the case secured her a new place as a hero at the fringes of the growing movement to promote psychedelic drug therapy.

Meckel appeared at Greenwich University earlier this year to speak at the third annual 'Breaking Convention' conference on psychedelic consciousness. One of the organisers, Ben Sessa, a Bristol-based psychiatrist, published a paper with Meckel in March describing her story and methods. It’s only in the past seven years or so that mainstream science has considered such drugs as MDMA and LSD in therapy. Results, though, in treating conditions including PTSD and anxiety, have been promising, and media attention, predictably, has been high.

In the UK, the political discussion tends to move in both directions at once: Theresa May’s Psychoactive Substances Bill, a prohibition effort to ban so-called ‘legal highs’, is making its way through the House of Commons; on Monday there was a debate on cannabis legalisation, the first to be forced by the new petition system, though the government responded by saying there would be no change in policy.

Even after being cast as a fight for users' rights, drug reform has never been a narrative of small iterative victories, or settled comfortably behind the lines of a single party. New Labour first, with great fanfare, relaxed and then six years later restrengthened the enforcement and punishment scheduling for cannabis. In 2009 they fired their senior drug policy adviser, David Nutt, for his criticisms of drug scheduling. 'He was asked to go because he cannot be both a government adviser and a campaigner against government policy,' Alan Johnson, the then home secretary, said.

Nutt was at the Breaking Convention conference too. He’s closer to the mainstream – a professor of neuropsychopharmacology at Imperial, with a Channel 4 special and a popular book – than Meckel and many others who were there, but since 2009 he has become perhaps the most important drug advocate in the world. When in government, Nutt was outspoken about the scientific consensus that most illegal drugs aren’t particularly harmful to their users – a failed rallying cry of drug reformists for nearly three decades. Now he has turned to the newly available argument that by limiting access to drugs, the government is preventing the scientific community from discovering potentially important benefits.

Science says these drugs are good only in the way that science says anything is good: in very specific circumstances with very specific caveats. But in a new field it's hard to argue against possibility. It remains to be seen whether the movement makes any headway in government, but we’re seeing the first major mainstream conversation on psychedelic drug use in 50 years, and anyone still hoping for liberalisation has the squares, from Meckel to Nutt, to thank for this trip.