There is a resurgence, some say renaissance, of clinical research on psychedelic substances after decades of dormancy. Recent studies have produced findings suggesting psychedelics may demonstrate substantial efficacy for serious psychiatric conditions such as mood and substance use disorders. As a result, ongoing clinical trials with the psychedelic psilocybin have been given the Breakthrough Therapy designation by the US Food and Drug Administration that could result in medical approval for major depressive disorder and/or treatment-resistant depression.