U.S. is about to legalize psilocybin and MDMA for clinical use in people with post-traumatic stress disorder or terminally ill cancer patients.

Scientists, patients, clandestine therapists and war veterans talk about the lights and shadows of this therapy. After half a century of prohibition, these substances are experiencing a second youth in a country plagued by an epidemic of mental health problems, fentanyl abuse and suicides. The place where Marjorie Smith tried the drug “for the first time” is a clinic in the suburb of Rockville (Maryland), north of Washington.