Mental-health and substance-use disorders — arguably more prevalent than ever during the pandemic ­— are a leading cause of disability globally. So it’s no wonder the clinical use of psychedelic drugs to help treat psychiatric disorders, including anxiety, depression, and PTSD, is fueling a research renaissance. Even Wall Street is taking notice: Three psychedelic drug developers have gone public in the last several months. Two leaders at the forefront of the field shed light on the science of psilocybin, MDMA, and ketamine and their use in psychedelic-assisted psychotherapy.