Kenneth Shinozuka, Burton J. Tabaac, Alejandro Arenas et al.
preprint
DMT, the psychedelic in ayahuasca, is being studied for depression. In a double-blind, placebo-controlled trial, ayahuasca led to remission in 36% of patients with treatment-resistant depression within one week. A Phase IIa trial reported that 57% of patients with major depressive disorder experienced remission 12 weeks after a single dose of DMT. DMT is naturally produced in the body, but likely at insignificant levels. The idea that DMT is released during death remains unproven. Ayahuasca can cause temporary vomiting but appears generally safe. More research is needed on DMT's therapeutic and biological roles.
Kenneth Shinozuka, Burton J. Tabaac, Alejandro Arenas et al.
preprint
MDMA, known as a party drug in the 1980s, is emerging as a powerful treatment for PTSD. Phase III FDA trials show MDMA-assisted psychotherapy has an effect size of 0.7-0.91, two to three times larger than existing antidepressants. Within 18 weeks, 67 to 71% of patients no longer meet PTSD diagnostic criteria. The literature is biased: animal studies used doses far above human levels, and human samples often involve recreational users of multiple substances. Only six clinical trials, all by MAPS, have been conducted, but preliminary evidence suggests MDMA is much more effective than current antidepressants for PTSD.
Viviana D. Evans, Alejandro Arenas, Kenneth Shinozuka et al.
preprint
Ketamine, originally a dissociative anesthetic, is now used for treatment-resistant depression and major depressive disorder with suicidal ideation. A single intravenous infusion shows antidepressant effects within hours, with a large effect size on depression scores. It also reduces PTSD symptom severity and suicidal ideation in emergency settings. However, therapeutic effects often subside within weeks, requiring repeated doses. Risks include temporary or persistent memory impairment, cardiovascular issues, liver toxicity, and bladder inflammation. Ketamine's opioid-sparing effect improves postoperative pain management.
Burton J. Tabaac, Kenneth Shinozuka, Anne Weisman et al.
preprint
5-MeO-DMT, a psychedelic found in toad venom and some plants, shows rapid antidepressant effects in early clinical trials. A Phase 2b trial reported that 57.5% of participants with treatment-resistant depression achieved remission within eight days. Other Phase 2a and 2b trials suggest it may reduce depressive symptoms more effectively than existing treatments like SSRIs. The substance appears low-risk in controlled settings, though most studies are small and only two double-blind randomized controlled trials have been conducted in clinical populations. Long-term effects need further study, and its possible link to near-death experiences remains debated.
Bryce D. Beutler, Kenneth Shinozuka, Burton J. Tabaac et al.
preprint
Lysergic acid diethylamide (LSD) shows promise for treating alcohol use disorder, anxiety, and depression, though its therapeutic potential remains incompletely understood. In clinical trials, adverse events have almost always been mild and transient, with serious events reported in none or very few participants. For anxiety and depression associated with life-threatening illnesses, 77% of participants demonstrate durable relief at one year post-treatment. A meta-analysis of randomized controlled trials found that single-dose LSD significantly improves alcohol use disorder with an odds ratio of 1.96. Large-scale prospective studies are needed to explore potential clinical applications.