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PTSD

A central target for MDMA-assisted therapy and related trauma-focused interventions.

State of the evidence

Synthesized

Synthesized from 25 studies in the library · AI-generated, grounded in the abstracts below

Found by searching the library for PTSD, post-traumatic stress disorder, traumatic stress, then ranked by relevance.

Research indicates that MDMA-assisted therapy and ketamine can reduce PTSD symptoms, with MDMA showing consistent, large effects in phase 2 and 3 trials, and ketamine showing rapid but less durable effects. However, evidence is limited by small sample sizes, short follow-up durations, and the need for more diverse populations and long-term safety data.

Confidence in the evidence

Moderate
  • Multiple phase 2 and 3 RCTs (e.g., article_id 16269, 14754) show consistent, large effect sizes for MDMA-assisted therapy, but sample sizes are modest (e.g., 90, 104 participants).
  • Ketamine studies (article_id 25630, 34433) are small (e.g., 41, 30 participants) and show rapid effects but limited durability data.
  • Long-term follow-up (article_id 16282) suggests durability of MDMA effects, but only in a small sample (n=19).
  • Systematic reviews (article_id 28489, 28654) confirm efficacy but highlight poor quality in some studies and need for more research.
How we rate confidence

Confidence reflects the strength of the underlying evidence, not whether the result is favorable. It weighs the number and size of studies, their design (randomized trials count for more than observational or single-case work), how consistently they point the same way, and their risk of bias.

Tiers run from Insufficient to High. High is rare in this field: small, early, or open-label studies land lower even when their direction is encouraging.

Evidence by study

Direction is each study's finding relative to your question: Supports, Opposes, No effect, Mixed, or Unclear.

MDMA-assisted therapy significantly reduced PTSD symptoms (CAPS-5) and functional impairment (SDS) compared to placebo, with large effect sizes.

RCT · Sample size: 90

This review discusses the therapeutic potential of psychedelic drugs but does not provide specific findings on PTSD.

review

A single intravenous ketamine infusion significantly reduced PTSD symptom severity compared to midazolam at 24 hours post-infusion.

RCT · Sample size: 41

MDMA-assisted psychotherapy did not show statistically significant reductions on the clinician-rated CAPS but did show significant self-reported improvement on the PDS.

RCT · Sample size: 12

MDMA-assisted therapy significantly reduced PTSD symptoms and functional impairment compared to placebo with therapy, with a large effect size.

RCT · Sample size: 104

Long-term follow-up (mean 45.4 months) showed that most participants maintained clinically significant symptom relief from MDMA-assisted psychotherapy, though two relapsed.

observational · Sample size: 19

Pooled analysis of six phase 2 trials showed MDMA-assisted psychotherapy significantly reduced PTSD symptoms compared to control, with a large effect size.

pooled analysis · Sample size: 103

This theoretical paper proposes that psychedelic-assisted therapy may be useful for trauma-induced personality disorders, but does not provide empirical data.

theoretical

This review discusses the potential of psychedelic psychiatry but does not provide specific findings on PTSD.

review

This review discusses the potential of MDMA, ketamine, classical psychedelics, and cannabinoids for PTSD, but does not provide specific quantitative findings.

review

Mindfulness-based cognitive therapy (MBCT) significantly improved PTSD symptoms compared to treatment-as-usual in combat veterans.

RCT · Sample size: 37

Repeated intravenous ketamine infusions over 2 weeks significantly reduced PTSD symptoms compared to midazolam, with a large effect size at week 2.

RCT · Sample size: 30

This review discusses psilocybin and MDMA for psychiatric disorders but does not provide specific findings on PTSD.

review

In patients with TRD and comorbid PTSD, esketamine treatment led to trauma re-experiencing episodes; in most cases these resolved, but in some treatment was stopped.

observational · Sample size: 22

This narrative review develops a neurocognitive account of C-PTSD and discusses MDMA-assisted psychotherapy as a potential intervention, but does not provide empirical data.

theoretical

MDMA-assisted therapy significantly reduced discrimination-related trauma symptoms, with a large effect size, but the sample was very small.

observational · Sample size: 5

In a specialized inpatient unit, PTSD symptoms significantly decreased after treatment, and reductions in dissociative symptoms were associated with improvements in PTSD.

observational · Sample size: 108

Ketamine produced dose- and band-frequency-dependent EEG power changes in TR-PTSD patients, which differed from TR-MDD and TR-OCD patients.

observational · Sample size: 22

This systematic review found that MDMA-assisted psychotherapy reduced PTSD symptoms across studies, with some evidence for decreased dissociative symptoms at higher doses.

systematic review · Sample size: 335

Individual participant data meta-analysis found that more psychotherapy sessions, more ketamine sessions, higher baseline severity, and shorter treatment duration predicted greater PTSD symptom improvement with ketamine-assisted psychotherapy.

meta-analysis · Sample size: 533

At-home telehealth-supported subcutaneous ketamine therapy was associated with significant reductions in PTSD symptoms (PCL-5) over 6 weeks in a large real-world cohort.

observational · Sample size: 3870

In rats, acute ethanol exposure before trauma exacerbated PTSD-like symptoms, and early intranasal ketamine reversed this effect.

preclinical

Points of agreement

  • MDMA-assisted therapy consistently reduces PTSD symptoms across multiple RCTs and a pooled analysis.
  • Ketamine, both single and repeated infusions, rapidly reduces PTSD symptoms.
  • Both MDMA and ketamine show large effect sizes in reducing PTSD symptoms.
  • Long-term follow-up of MDMA-assisted therapy suggests durability of symptom relief.

Conflicts

  • One early MDMA trial (article_id 22029) found non-significant results on the clinician-rated CAPS but significant self-reported improvement, while later trials found significant effects on both.
  • Esketamine treatment for comorbid TRD and PTSD led to trauma re-experiencing episodes in some patients, which is a potential adverse effect not reported in other ketamine studies.
  • The durability of ketamine's effects is less established compared to MDMA, with most studies focusing on short-term outcomes.

Gaps

  • Long-term durability of ketamine's effects on PTSD is not well studied.
  • Most studies have small sample sizes, limiting generalizability.
  • There is limited research on diverse populations, including racial/ethnic minorities and individuals with complex comorbidities.
  • The optimal dosing, number of sessions, and integration with psychotherapy for both MDMA and ketamine are not fully established.
  • Safety and efficacy in real-world settings, especially for at-home ketamine, require more research.
  • The role of psychedelic-assisted therapy for complex PTSD and borderline personality disorder is understudied.
Browse these studies in the library
How we analyze this

This synthesis reads the 15 most-cited and 10 most recent studies whose primary subject is PTSD, up to 25 in all. The most-cited set anchors the established evidence, and the recent set surfaces work that is too new to have gathered citations yet.

A study qualifies only when PTSD or a known alias appears in its title or keywords, so broad reviews that mention it only in passing are left out. Each study is read from its abstract, strongest evidence first, and the summary reports the direction of the results along with any conflicts and gaps.

1,024 articles · 483 from the last two years · 250,690 participants across 335 studies reporting sample size

Common study designs

review 289 systematic review 52 observational cohort 32 randomized controlled trial 46 theoretical or philosophical paper 81

A chromosome level reference genome of Diviners sage (Salvia divinorum) provides insight into salvinorin A biosynthesis

bioRxiv (Cold Spring Harbor Laboratory) • Scott A. Ford, Rob W. Ness, Moonhyuk Kwon et al. preprint

A chromosome-level genome assembly of the diviners sage plant, which produces the hallucinogen salvinorin A, has been produced. The genome is about 541 million base pairs, diploid, and comparable to other sage species. Two gene clusters involved in diterpene biosynthesis were identified, including a gene that forms the dihydrofuran ring early in the salvinorin A pathway. Other enzyme classes likely involved in later steps are scattered across the genome. Most of these genes are not activated by methyl jasmonate treatment. This high-quality genome sequence will help uncover the remaining steps in salvinorin A biosynthesis and support exploration of its medical potential for chronic pain, addiction, and post-traumatic stress disorder.

Psychedelic Therapy: A Primer for Primary Care Clinicians – Part VII. Ketamine

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.

MDMA-Based Psychotherapy in Treatment-Resistant Post-traumatic Stress Disorder (PTSD): A Brief Overview of Current Evidence

Preprints.org • Kainat Riaz, Sejal Suneel, Mohammad Hamza Bin Abdul Malik et al. • 1 citation preprint

Half of patients with post-traumatic stress disorder (PTSD) do not respond to standard pharmacotherapy or psychotherapy. A review of six phase II randomized controlled trials indicates that MDMA-assisted psychotherapy can reduce PTSD symptoms, even in treatment-resistant cases, by increasing neurohormones such as dopamine, serotonin, norepinephrine, and oxytocin and by modulating brain regions involved in fear and anxiety. The FDA has granted MDMA-assisted psychotherapy a "Breakthrough Therapy" designation. Further research is needed to determine whether the benefits outweigh the risks and whether this approach can be integrated into existing treatment options.

MDMA Assisted Psychotherapy Decreases PTSD Symptoms, Dissociation, Functional Disability, and Depression: A Systematic Review and Meta-Analysis

medRxiv • W. M. Green, S.b. Raut, F.l.j. James et al. • 4 citations preprint

MDMA-assisted psychotherapy improves dissociation, depression, and functional impairment in people with post-traumatic stress disorder (PTSD), but does not improve sleep quality. A systematic review and meta-analysis of randomized controlled trials found that the therapy reduces core PTSD symptoms and enhances quality of life. The evidence is limited by small sample sizes in available trials, but supports further development of MDMA-assisted psychotherapy for PTSD.

Psychedelic Therapy: A Primer for Primary Care Clinicians – Part VI. 3,4-methylenedioxy-methamphetamine (MDMA)

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.

MDMA-Assisted Therapy for Complex-Post-Traumatic Stress Disorder: Toward a neurocognitive account

Philip Gerrans, Hugh Mgovern, Jakob Hohwy et al. • 1 citation preprint

Complex post-traumatic stress disorder (C-PTSD) involves additional symptoms beyond those of PTSD, including emotional instability, negative self-concept, and interpersonal difficulties, often from prolonged trauma like childhood maltreatment or domestic violence. A novel model based on active inference and self-modelling explains these differences and identifies the insula's role in affective regulation. The model suggests that MDMA-assisted therapy may help recalibrate emotional regulation and strengthen self-model, offering a potential treatment avenue. Theoretical and clinical implications are discussed, with emphasis on further empirical research.

Too big to fail? Comparing effect sizes of MDMA assisted therapy to unmasking bias

Balazs Szigeti, Ellen Bradley, Joshua Woolley preprint

Unmasking bias—where participants or researchers can guess who received a treatment due to its noticeable effects—may account for the reported benefits of MDMA-assisted therapy for PTSD. Analyzing data from trials of ketamine and escitalopram, the authors found that the magnitude of unmasking bias is larger than the treatment-versus-control effect size observed for MDMA. This indicates that MDMA-AT's effect sizes are not too large to be explained by unmasking alone, though the findings do not prove that the effects are entirely or partially due to this bias.

Expectancy effects cannot be neglected in MDMA-assisted therapy research

L. J. Flameling, Jacob S. Aday, Michiel van Elk • 1 citation preprint

A commentary on a phase 3 trial of MDMA-assisted therapy for PTSD raises concerns about expectancy effects. The trial reported positive results, but most participants correctly guessed their treatment assignment, and expectations were not measured. The authors argue these effects were minimal, but the commentary contends that without measuring expectations, it remains possible that placebo or nocebo effects contributed to the observed outcomes.

The FDA Backdoor to MDMA Rescheduling

SSRN Electronic Journal • Vincent Joralemon

The Drug Enforcement Administration (DEA) classifies MDMA as a Schedule I controlled substance, the most restrictive category under the Controlled Substances Act. However, Lykos Therapeutics (formerly MAPS PBC) has submitted a New Drug Application for MDMA-assisted therapy for PTSD. If the FDA approves this drug, it would provide the 'accepted medical use' that Schedule I drugs are statutorily denied, triggering a rescheduling process. Based on precedents like XYWAV and cannabis-derived medications, the DEA would likely reschedule only the specific FDA-approved drug product—likely to be marketed as RENSANSE—to Schedule II or III, while raw MDMA remains on Schedule I. This mechanism offers a model for incrementally relaxing federal restrictions on psychedelic substances and expanding research access.

Brain State Dynamics in Ketamine-Induced Dissociation Resemble Those in PTSD

Noam Goldway, Taly Markovits, Naomi Fine et al. preprint

Dissociation—feeling detached from one's body, surroundings, or self—is common in PTSD but its neural basis is poorly understood. Using network control theory, researchers examined brain dynamics during dissociative states in two contexts: ketamine-induced dissociation in 30 healthy volunteers and therapeutic interventions in 78 PTSD patients. Ketamine produced brain dynamics similar to those seen in PTSD patients before treatment, with increased dominance of a default mode network meta-state and decreased dominance of a somatomotor meta-state. Ketamine did not significantly alter the brain's energetic landscape, but transition energies increased after PTSD treatment, suggesting more organized, less entropic brain dynamics.

Clinical trials

All PTSD trials →