Psychedelic drugs are gaining popularity in the pharmaceutical R&D sector because of their apparent benefits for people suffering with neuropsychiatric disorders – and those which are resistant to existing therapies in particular. In this article, Imperial College London’s Professor David Nutt discusses the evidence underlying the development of psychedelic therapies using MDMA for indications such as addiction and post-traumatic stress disorder (PTSD) and what the industry could do to capitalise on their therapeutic potential.