MDMA and memory, addiction, and depression: dose-effect analysis
Madeline M. Pantoni, Jinah L. Kim, Kaitlin R. Van Alstyne, Stephan G. Anagnostaras
Psychopharmacology March 1, 2022 DOI: 10.1007/s00213-022-06086-9 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Dose-ranging experimental animal study Peer reviewed |
|---|---|
| Population | Mice |
| Intervention | MDMA |
| Dose | 0.01 to 10 mg/kg |
| Measures | Pavlovian fear conditioning, behavioral sensitization, conditioned place preference, conditioned responding, Porsolt forced swim test |
| Topics | Addiction Depression MDMA |
| Key findings | High doses of MDMA (3 mg/kg and above) produced amnesia of fear conditioning memory, some evidence of addictive potential, and antidepressant effects in mice, while low doses (1 mg/kg and below) had no effect on these behaviors. The authors conclude that 3 mg/kg is the threshold for MDMA-induced amnesia and argue that high doses should likely be avoided, whereas low clinical doses (about 1-2 mg/kg) show little evidence of these adverse effects. |
Abstract
Abstract Rationale ±3,4-Methylenedioxymethamphetamine (MDMA) is a recreational drug that shows substantial promise as a psychotherapeutic agent. Still, there is some concern regarding its behavioral toxicity, and its dose-effect relationship is poorly understood. We previously explored the role of dose in the cognitive effects of MDMA in a systematic review of existing literature and found no evidence in animals that MDMA impairs memory at low doses (< 3 mg/kg) but mixed results at high doses (≥ 3 mg/kg). Since this review comprised mostly of single-dose studies and an assortment of methodologies, an empirical dose-ranging study on this topic is warranted.
Objectives: The current study aims to evaluate the conclusion from our systematic review that 3 mg/kg may be the threshold for MDMA-induced amnesia, and to further understand the dose-effect relationship of MDMA on behavioral assays of memory, addiction, and depression.
Methods: We systematically examined the effects of 0.01 to 10 mg/kg MDMA on Pavlovian fear conditioning; behavioral sensitization, conditioned place preference, and conditioned responding; and the Porsolt forced swim test in mice.
Results: High doses of MDMA (≥ 3 mg/kg) produced amnesia of fear conditioning memory, some evidence of an addictive potential, and antidepressant effects, while low doses of MDMA (≤ 1 mg/kg) had no effect on these behaviors.
Conclusions: The present dose-ranging study provides further evidence that 3 mg/kg is the threshold for MDMA-induced amnesia. These findings, in addition to our systematic review, demonstrate that careful selection of MDMA dose is critical. High doses (≥ 3 mg/kg) should likely be avoided due to evidence that they can produce amnesia and addiction. Conversely, there is little evidence to suggest that low doses, which are usually administered in clinical studies (approximately 1–2 mg/kg), will lead to these same adverse effects. Ultra-low doses (< 1 mg/kg) are likely even safer and should be investigated for therapeutic effects in future studies.