Remembering Molly: Immediate and delayed false memory formation after acute MDMA exposure
Lilian Kloft, Henry Otgaar, Arjan Blokland, Stefan W. Toennes, Johannes G. Ramaekers
European Neuropsychopharmacology February 3, 2022 DOI: 10.1016/j.euroneuro.2022.01.005 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Double-blind, placebo-controlled trial Peer reviewed |
|---|---|
| Sample size | 60 |
| Population | Healthy volunteers with a history of MDMA use |
| Intervention | MDMA |
| Dose | 75 mg |
| Duration | Immediate test and 1-week follow-up |
| Topics | MDMA |
| Keywords | False memory Memory errors Recall Context archaeology Misinformation Cognitive psychology Suggestibility Episodic memory Eyewitness memory Cognition Computer security |
| Citations | 17 |
| Key findings | MDMA increased false memory for related but non-critical lures during immediate testing but decreased false memory for critical lures after a one-week delay, and did not consistently affect episodic memory in misinformation tasks. |
Abstract
The entactogen 3,4-Methylenedioxymethamphetamine (MDMA) is increasingly being recognized for its therapeutic potential but is also widespread in nightlife settings where it may co-occur with crime. Since previous research detected impaired verbal memory during acute MDMA intoxication, understanding the drug's ramifications in an applied legal context becomes crucial. We conducted a double-blind, placebo-controlled trial to examine acute and delayed effects of MDMA (75 mg) on false memory in 60 healthy volunteers with a history of MDMA use, using three well-established false memory methods: a basic, associative word list (Deese/Roediger-McDermott (DRM)) paradigm and two applied misinformation tasks using a virtual reality crime. Memory was tested immediately (encoding and retrieval under drug influence) and 1 week later (retrieval when sober). Small MDMA-induced impairments of true memory in the word list task were detected at both time points. MDMA increased false memory for related but non-critical lures during the immediate test, and decreased false memory for critical lures after a delay. Episodic memory assessed in the misinformation tasks was not consistently affected. Findings indicate a complex memory profile but no heightened vulnerability to external suggestion in response to MDMA intoxication. Recommendations for future applied legal psychological research include adding measures of recall on top of recognition, using study designs that separate the different memory phases, and potentially testing higher doses. Further research on false memories and suggestibility using imagination procedures can also be relevant for the clinical context.
Comparable studies
Other randomized controlled trials on MDMA, most cited first.
Citations in the library
Cited by 8
- MDMA and MDMA-Assisted Therapy. American Journal of Psychiatry 2025
- Cognitive functioning associated with acute and subacute effects of classic psychedelics and MDMA - a systematic review and meta-analysis. Scientific Reports June 26, 2024
- Psychedelics and autobiographical memory - six open questions. Psychopharmacology March 17, 2025
- Ayahuasca enhances the formation of hippocampal-dependent episodic memory without impacting false memory susceptibility in experienced ayahuasca users: An observational study. Journal of Psychopharmacology April 1, 2025
- Subjective and neurocognitive profiling of clinical doses of 3,4-methylenedioxymethamphetamine (MDMA) in healthy volunteers: implications for therapeutic use Molecular Psychiatry April 8, 2026
and 3 more in the library
Cites 23
- 3,4-methylenedioxymethamphetamine (MDMA)-assisted psychotherapy for post-traumatic stress disorder in military veterans, firefighters, and police officers: a randomised, double-blind, dose-response, phase 2 clinical trial. The Lancet Psychiatry May 1, 2018
- 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
- Distinct acute effects of LSD, MDMA, and d-amphetamine in healthy subjects Neuropsychopharmacology November 16, 2019
- MDMA-assisted psychotherapy for PTSD: Are memory reconsolidation and fear extinction underlying mechanisms? Progress in Neuro-Psychopharmacology and Biological Psychiatry June 8, 2018
- Pharmacology of MDMA in Humans Annals of the New York Academy of Sciences September 1, 2000
and 18 more in the library