There has been an explosion of clinical trials involving psychedelic drugs for treatment resistant mental health problems in the UK. Three major trials of psilocybin the active ingredient in magic mushrooms, started in London earlier this year. The US Food and Drug Administration licensed a variant of the party drug Ketamine for treatment-resistant depression. But are these drugs the greatest breakthrough in psychiatry since modern anti-depressants and anti-psychotics or are the benefits only temporary or placebo? Listen to my BBC Radio 4 report.