Transient memory impairment after acute dose of 75mg 3.4-Methylene-dioxymethamphetamine

Introduction

Earlier research has reported cognitive deficits, especially verbal memory impairment, in people who use 3,4-methylenedioxymethamphetamine (MDMA, Ecstasy). Those between-group and abstinent-user studies have suggested dose-related memory problems and links to serotonergic markers, but interpretation is limited by confounding factors such as unknown dosing, polydrug use, lifestyle differences and the lack of experimental control. Only a few studies attempted to assess memory during intoxication, and those employed quasi-experimental designs (for example assessing users who self-administered MDMA before parties), which left open alternative explanations including sleep loss and uncontrolled substance use. Kuypers and colleagues designed a controlled experiment to test whether a single acute dose of MDMA produces immediate and/or residual memory impairment. The study used a double-blind, placebo-controlled, three-way crossover design in experienced recreational MDMA users, including an active control (methylphenidate) to probe whether any observed effects were likely dopaminergic rather than serotonergic in origin. The primary focus was on verbal memory measured during the intoxication phase (about 1.5 h post-dose) and the withdrawal phase (about 25.5 h post-dose).