PSYCHEDELICS AND ENTACTOGENS IN PSYCHIATRY: PHARMACOLOGY, CLINICAL TRIAL EVIDENCE, AND REGULATORY CONSIDERATIONS

Psychedelics, including psilocybin, lysergic acid diethylamide, and dimethyltryptamine, and entactogens such as 3,4-methylenedioxymethamphetamine are being investigated for treatment-resistant depression, post-traumatic stress disorder, anxiety, and substance use disorders. These compounds act primarily through serotonin 5-HT2A receptor agonism (psychedelics) or monoamine release (MDMA), leading to acute alterations in consciousness that may enhance neuroplasticity and emotional processing. Randomized controlled trials have shown rapid and sustained reductions in depressive and post-traumatic stress symptoms following one or two assisted psychotherapy sessions. Psilocybin has received breakthrough therapy designation from the US FDA for treatment-resistant depression and major depressive disorder, while MDMA-assisted therapy for post-traumatic stress disorder has completed phase 3 trials with positive results, though regulatory review has raised methodological and safety concerns. This review critically examines the pharmacology, clinical evidence, and regulatory considerations for psychedelics and entactogens, focusing on literature through mid-2025. Challenges include blinding, expectancy effects, therapist training, and long-term safety. Future directions include dose optimization, identification of biomarkers, and integration into mental health care. While promising, these therapies require rigorous evaluation and careful regulatory oversight.