Psychedelic drugs are substances that alter perception and mood and affect a number of cognitive processes. The classic psychedelics include MDMA aka "ecstasy" or "molly," LSD, psilocybin or "mushrooms," ayahuasca and ibogaine. Used in conjunction with therapists, research has shown that psychedelics can help treat historically difficult-to-treat conditions by essentially "reshaping" the way "parts of the brain talk to each other," says Jennifer Mitchell, a neuroscientist. "Psychedelics allow for processing in a way that enables subjects to let go of things that had previously plagued them," she says. As Mitchell explains it, when people are young, their brains go through critical periods of learning and development that then become closed off as they age. Researchers believe that psychedelics "open those closed critical periods for just a tiny window of time," she says. "When that critical period is open again, you want to make the most of it, and make that potential change as positive as possible," she says. With psilocybin, for instance, it is believed the drug boosts connectivity in the brain and increases "neuroplastic states," which are the brain's ability to reorganize and adapt, says Dr. Stephen Ross ... who has been conducting clinical trials on psilocybin-assisted therapy for the past 16 years. MDMA-assisted therapy could be approved by the FDA for medical use as early as 2023, while other psychedelics, notably psilocybin, are waiting in the wings for their turn to be evaluated for medical purposes.