Psychedelic-assisted therapy (PAT) merges psychotherapy with psychedelic states, facilitated by substances like LSD, psilocybin, and MDMA, showing potential in treating PTSD, TRD, MDD, and other conditions. Despite being classified as Schedule I drugs, their therapeutic potential is increasingly recognized, leading to FDA Breakthrough Therapy designations for MDMA and psilocybin. Recent research suggests these substances reopen a 'critical period' in the brain, enhancing social reward learning and brain plasticity. Methodologically rigorous clinical research indicates substantial long-term symptom alleviation, with single sessions leading to significant symptom reduction and remission lasting up to twelve months. Despite regulatory challenges, ongoing research and clinical trials continue to explore and validate the therapeutic benefits of PAT.