PTSD
Posttraumatic stress disorder (PTSD) is a significant mental health challenge affecting over 354 million individuals globally. Psychedelics, particularly MDMA and psilocybin, are emerging as promising therapeutic options, offering new avenues for treatment through innovative psychotherapeutic interventions.
Key Insights
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MDMA-assisted therapy has demonstrated very large effects, with 56% of participants no longer meeting PTSD criteria in early trials.
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The majority of participants in MDMA trials were war veterans, a demographic which shows higher PTSD prevalence compared to the general population.
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Ketamine shows promise in reducing PTSD symptoms, but results are mixed, with some studies indicating limited dosage effects and transient benefits.
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Mescaline remains under-researched in PTSD treatment, but user surveys suggest potential symptom improvement.
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Psychedelics like MDMA may 'reopen' critical periods for emotional processing, facilitating therapeutic breakthroughs.
What is PTSD?
Posttraumatic stress disorder (PTSD) is a psychiatric condition that arises following a traumatic event, including natural disasters, violence, war, and sexual assault. The disorder is characterised by a range of symptoms grouped into four categories: intrusive memories, avoidance behaviours, negative changes in cognition and mood, and alterations in emotional and physical responses.
Common symptoms include distressing recollections of the traumatic experience, avoidance of reminders, negative self-perception, heightened startle response, and emotional numbing. To be diagnosed with PTSD, a person must exhibit symptoms persisting for more than one month, which disrupt daily functioning.
Current Treatments
Standard treatment for PTSD often combines psychotherapy (including cognitive processing therapy and prolonged exposure therapy) with pharmacotherapy, predominantly SSRIs such as paroxetine and sertraline. Anxiolytics may be used short-term, but they carry an abuse risk.
Psychedelic Effect Matrix
Compound efficacy and evidence levels for PTSD.
| Compound | Magnitude | Evidence | Consistency |
|---|---|---|---|
| MDMA Strong evidence from multiple Phase II and Phase III trials shows substantial efficacy in treating PTSD. | Large | High | Consistent |
| Ketamine Initial positive trials indicate efficacy but larger studies yield mixed results. | Medium | Moderate | Inconsistent |
| Psilocybin Emerging research suggests potential benefits, but more rigorous studies are needed. | Small | Low | Inconsistent |
| Mescaline Limited surveys suggest anecdotal benefits without controlled trials. | Small | Very Low | Inconsistent |
MDMA and PTSD
MDMA is classified as an entactogen, which promotes feelings of emotional openness and empathy—critical for processing traumatic experiences. It functions primarily by increasing serotonin levels, thereby enhancing emotional fluidity during therapeutic sessions. This heightened state of receptiveness enables therapeutic breakthroughs as individuals confront and reframe their traumatic memories with the guidance of a trained therapist.
Ketamine and PTSD
Ketamine acts as an NMDA receptor antagonist, leading to an increase in glutamate levels which may stimulate synaptogenesis and enhance neural activity. This mechanism is theorised to alleviate depressive symptoms associated with PTSD, although the lack of structured therapy in studies complicates the understanding of its efficacy specifically for PTSD treatment.
Industrial Landscape
Key players in this field include MAPS (Multidisciplinary Association for Psychedelic Studies), which has been pivotal in advancing MDMA therapy; Numinus, focusing on therapeutic psychedelic applications; and Seelos Therapeutics, working on ketamine formulation. Non-profits such as Healing Breakthrough and Remedy are also instrumental in research and clinical applications for PTSD.
Quick Indicators
Key Organizations
12Janssen Research & Development
Janssen Research & Development is the pharmaceutical research and development arm of Johnson & Johnson (J&J). Operating under J&J's Innovative Medicine division, Janssen has sponsored clinical trials into ketamine-derived compounds, including esketamine (Spravato), the first FDA-approved psychedelic-adjacent treatment for treatment-resistant depression.
Algernon Pharmaceuticals
Algernon Pharmaceuticals (also known as Algernon Health / Algernon NeuroScience) is the first company in the world to test DMT as an emergent treatment for ischemic stroke and traumatic brain injury. Their lead candidate AP-188 uses sub-hallucinogenic IV DMT to promote neuroplasticity and neuroprotection. Phase 1 completed at the Centre for Human Drug Research in Leiden; Phase 2a stroke trial planned.
Clexio Biosciences
Clexio Biosciences is a private Israeli clinical-stage CNS company founded in 2018 by Teva Pharmaceuticals R&D veterans. Their lead programme CLE-100 is a once-daily oral tablet formulation of esketamine for MDD — distinguished from the FDA-approved Spravato (intranasal, in-clinic) by enabling outpatient, at-home use. Phase 2 CLEO study results showed a promising safety profile and encouraging efficacy specifically in post-COVID MDD subgroups; the Phase 2 SOLEO study (NCT06340958, higher dose, stricter treatment-resistance criteria) enrolled first patients April 2024 and reached 50% enrollment by December 2024. CLE-100 holds multiple US method-of-use patents (2024). In December 2025, Clexio spun out its muscarinic agonist programme (CLE-905) into a new entity, Syremis Therapeutics, which raised $165M Series A co-led by Dexcel Pharma and Third Rock Ventures. Co-founders Kogan, Levy, and Kagan simultaneously lead Syremis; Clexio continues independently with CLE-100 and preclinical CLE-043.
OPEN Foundation
The OPEN Foundation is a Dutch non-profit organisation that advances psychedelic research and therapy through scientific conferences, interdisciplinary research, clinician training, and public education. It organises events (including the ICPR conference), runs research and training programmes, and advocates for ethical integration of psychedelics into healthcare in the Netherlands and Europe.
Clerkenwell Health
Clerkenwell Health (trading as Clerkenwell Clinics Limited) is a UK-based clinical research organisation that designs and runs psychiatry and central nervous system (CNS) clinical trials and provides psychedelic-assisted therapy services. It operates specialist clinics and site networks to support early-phase CNS and mental-health research.
Exeter University
The University of Exeter is a public research university based in Exeter, Devon, England, with additional campuses in Cornwall. It provides undergraduate and postgraduate education and conducts research across a wide range of disciplines.
Cybin
Cybin Inc. (founded 2019) is a Canadian clinical-stage biopharmaceutical company developing psychedelic-based therapeutics—now operating as Helus Pharma—focused on proprietary novel serotonergic agonists and deuterated psilocin analogs for mental health conditions.
Ohio State University
The Ohio State University is a public land-grant research university based in Columbus, Ohio, offering undergraduate, graduate, and professional programs and conducting research across many fields. It was founded as the Ohio Agricultural and Mechanical College and serves as a major educational and economic institution in Ohio.
COMPASS Pathways
COMPASS Pathways is a UK-listed biopharmaceutical company developing COMP360 synthetic psilocybin therapy for treatment-resistant depression, with two successful Phase 3 trials making it the leading candidate for the first regulatory approval of a classic psychedelic medicine.
Diamond Therapeutics
Diamond Therapeutics is a private Canadian clinical-stage company pioneering sub-perceptual (non-hallucinogenic) psilocybin therapy. Their approach focuses on low-dose psilocybin that does not produce psychedelic experiences, enabling at-home outpatient administration — a differentiated strategy from the clinic-based, high-dose psychedelic-assisted therapy model. Founded in 2018 by CEO Judith Blumstock, Diamond completed a Phase 1 single ascending dose study in healthy volunteers (n=56, 7 cohorts, December 2022) establishing a safe non-hallucinogenic dose range. Their Phase 2a GAD programme received Health Canada approval in January 2023 — the first Health Canada NOL for a psychedelic trial in GAD — and enrolled first patients at Kingston Health Sciences Centre in 2025 in the first-ever at-home microdose psilocybin study. A parallel FDA-authorized Phase 2 demoralization trial is also underway at UAB. Diamond is funded by private investors and non-dilutive public grants, including a $1.1M+ CQDM/Brain Canada drug discovery consortium launched in May 2025.
Definium Therapeutics
Definium Therapeutics (formerly Mind Medicine / MindMed) is a late-stage clinical biopharmaceutical company headquartered in New York, founded in 2019 and rebranded in January 2026. Led by CEO Robert Barrow, the company applies scientific rigor to psychedelic-derived molecules to develop accessible, rapidly-acting psychiatric treatments. Its lead asset, DT120 ODT (formerly MM-120) — a pharmaceutically optimised formulation of lysergide D-tartrate (LSD) as an orally disintegrating tablet — has received FDA Breakthrough Therapy Designation for generalised anxiety disorder (GAD) and delivered compelling Phase 2b results: 65% clinical response rate and 48% remission at 12 weeks following a single dose. Three Phase 3 trials are currently underway: Voyage and Panorama (GAD) and Emerge (MDD, fully enrolled). Topline data from all three studies is expected in 2026, potentially positioning Definium for the first-ever FDA approval of an LSD-derived therapy. A second pipeline asset, DT402 (formerly MM402) — an MDMA-related compound — is in Phase 1 development for autism spectrum disorder.
Lobe Sciences
Canadian psychedelic biotech developing conjugated psilocin formulations for treatment-resistant conditions. Spun out its proprietary Conjugated Psilocin™ technology to Cynaptec Pharmaceuticals in April 2025 via an $8.46 million financing round. Lead programme L-130 targets cluster headache disorder.
Prominent Researchers
4Moshe Kotler
Roland Griffiths
Professor of Neuroscience and Psychiatry
Seminal figure in the modern 'psychedelic renaissance' and founding director of the Johns Hopkins Center for Psychedelic and Consciousness Research.
Matthias Liechti
Professor of Clinical Pharmacology
World-leading clinical researcher focusing on the human pharmacology of MDMA, LSD, and other psychoactive substances at the University of Basel.
Boris Heifets
Neuroscientist
Noted for translational research clarifying how opioid-receptor signalling interacts with ketamine’s antidepressant and antisuicidal effects and for contributions that bridge preclinical psychedelic pharmacology and clinical trials.
Connected Evidence
The latest clinical data and verified academic findings associated with PTSD.