MDMA as an early post-trauma intervention in a translational animal model of PTSD.
Omer Baruch, Nadav Reiss, Doron Todder, Joseph Zohar, Hagit Cohen
Progress in Neuro-Psychopharmacology and Biological Psychiatry July 24, 2026 DOI: 10.1016/j.pnpbp.2026.111853 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Controlled animal study Peer reviewed |
|---|---|
| Sample size | 175 |
| Population | Adult male Sprague-Dawley rats |
| Intervention | MDMA |
| Dose | 2.5, 5, or 10 mg/kg |
| Duration | Single injection, behavioral assessments on days 7-8 |
| Measures | elevated plus-maze, acoustic startle response, contextual freezing, urinary corticosterone, norepinephrine, hippocampal glucocorticoid receptor (GR), norepinephrine transporter (NET), c-Fos, tryptophan hydroxylase 2 (TPH2), oxytocin, tyrosine hydroxylase (TH) immunoreactivity |
| Topics | MDMA PTSD Serotonin |
| Keywords | Animal model Early intervention Glucocorticoids Memory processing Oxytocin |
| Key points | MDMA at 10 mg/kg, administered 30 minutes after predator scent stress or 24 hours later with trauma-cue pairing, reduced anxiety-like behavior, startle amplitude, contextual freezing, and extreme behavioral responses, whereas lower doses and unpaired delayed administration were ineffective. Effective treatment increased corticosterone and hippocampal GR levels and enhanced c-Fos, TPH2, oxytocin, GR, and TH expression in stress-regulatory circuits. |
Abstract
Post-traumatic stress disorder (PTSD) remains difficult to prevent after trauma, highlighting the need for early interventions that reduce the risk of chronic symptom development. This controlled study investigated the preventive potential of 3,4-methylenedioxymethamphetamine (MDMA) in a validated rat model of PTSD induced by predator scent stress (PSS). Adult male Sprague-Dawley rats (N = 175) were exposed to PSS or sham-PSS and treated intraperitoneally with MDMA (2.5, 5, or 10 mg/kg) or saline. MDMA was administered either 30 min after PSS or 24 h later, with or without trauma-cue pairing. Behavioral outcomes included the elevated plus-maze and acoustic startle response assessments on day 7 for phenotypic classification, followed by contextual freezing on day 8. Urinary corticosterone and norepinephrine, hippocampal glucocorticoid receptor (GR) and norepinephrine transporter (NET), and c-Fos, tryptophan hydroxylase 2 (TPH2), GR, oxytocin, and tyrosine hydroxylase (TH) immunoreactivity were measured 1 h post-injection in stress-related brain regions. The 10 mg/kg MDMA dose significantly reduced anxiety-like behavior, startle amplitude, contextual freezing, and the prevalence of extreme behavioral responses when administered 30 min after PSS or 24 h later with trauma-cue pairing. Lower doses and unpaired delayed administration were largely ineffective. The effective dose increased urinary corticosterone and hippocampal GR levels, and enhanced c-Fos, TPH2, oxytocin, GR, and TH expression in stress-regulatory circuits. Trauma-cue pairing further strengthened MDMA-induced increases in GR, oxytocin, and TPH2. These findings suggest that MDMA was associated with dose-, timing-, and context-dependent reductions in PTSD-like outcomes, accompanied by neurochemical signatures consistent with enhanced stress regulation, neuroplasticity, and adaptive memory processing.
In the evidence
This study is part of the evidence base for a synthesis in the library. Here is how each one recorded it.
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State of the evidence: MDMA for PTSD Supports
MDMA at 10 mg/kg given 30 minutes after stress or 24 hours later with trauma-cue pairing reduced anxiety-like behavior, startle, and freezing, while lower doses and unpaired delayed administration were ineffective.
Synthesized
Comparable studies
Other preclinical and animal studies on MDMA for PTSD, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| MDMA treatment paired with a trauma-cue promotes adaptive stress responses in a translational model of PTSD in rats Rats exposed to predator-scent stress | 2022 | Controlled prospective study | |
| Psychedelics: A review of their effects on recalled aversive memories and fear/anxiety expression in rodents Rodents | 2024 | Review | |
| Examining the Role of Oxytocinergic Signaling and Neuroinflammatory Markers in the Therapeutic Effects of MDMA in a Rat Model for PTSD. Male rats | 2024 | Preclinical study | |
| MDMA administration attenuates hippocampal IL-β immunoreactivity and subsequent stress-enhanced fear learning: An animal model of PTSD Male rats | 2022 | Preclinical study | |
| Methylone is a rapid-acting neuroplastogen with less off-target activity than MDMA Rats | 2024 | Preclinical study |
Citations in the library
Cites 16
- MDMA-assisted therapy for severe PTSD: a randomized, double-blind, placebo-controlled phase 3 study. Nature Medicine June 1, 2021
- MDMA-assisted therapy for moderate to severe PTSD: a randomized, placebo-controlled phase 3 trial. Nature Medicine October 1, 2023
- MDMA-assisted psychotherapy for treatment of PTSD: study design and rationale for phase 3 trials based on pooled analysis of six phase 2 randomized controlled trials. Psychopharmacology September 1, 2019
- MDMA-assisted psychotherapy for PTSD: Are memory reconsolidation and fear extinction underlying mechanisms? Progress in Neuro-Psychopharmacology and Biological Psychiatry June 8, 2018
- 3,4-Methylenedioxymethamphetamine facilitates fear extinction learning Translational Psychiatry September 15, 2015
and 11 more in the library