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Acute effects of MDMA (3,4-methylenedioxymethamphetamine) on EEG oscillations: alone and in combination with ethanol or THC (delta-9-tetrahydrocannabinol).

Marieke M Lansbergen, Glenn Dumont, Joop van Gerven, Jan K. Buitelaar, Robbert Jan Verkes

Psychopharmacology February 2011 DOI: 10.1007/s00213-010-2031-4 (opens in new tab)

Study at a glance

AI-extracted from the abstract
Characteristics Randomized controlled trial Peer reviewed
Sample size 16
Population Healthy volunteers
Interventions MDMA Alcohol THC
Dose MDMA 100 mg; alcohol clamp to blood alcohol concentration 0.6‰; THC inhalation of 4, 6, and 6 mg at 1.5-hour intervals
Measures EEG power in theta and alpha bands
Topics Cannabis MDMA
Key findings Combined intake of MDMA and THC, but not MDMA and alcohol, affects ongoing EEG oscillations differently than the sum of each drug alone. Specifically, MDMA and THC together produced less attenuation of theta and lower-1-alpha power than expected additively, and significantly decreased lower-2-alpha power, which neither drug did alone.

Abstract

Typical users of 3,4-methylenedioxymethamphetamine (MDMA or "ecstasy") are polydrug users, combining MDMA with alcohol or cannabis [most active compound: delta-9-tetrahydrocannabinol (THC)]. The aim of the present study was to investigate whether co-administration of alcohol or THC with MDMA differentially affects ongoing electroencephalogram (EEG) oscillations compared to the administration of each drug alone. In two separate experiments, 16 volunteers received four different drug conditions: (1) MDMA (100 mg); (2) alcohol clamp (blood alcohol concentration = 0.6‰) or THC (inhalation of 4, 6 and 6 mg, interval of 1.5 h); (3) MDMA in combination with alcohol or THC; and (4) placebo. Before and after drug administration, electroencephalography was recorded during an eyes closed resting state. Theta and alpha power increased after alcohol intake compared to placebo and reduced after MDMA intake. No interaction between alcohol and MDMA was found. Significant MDMA x THC effects for theta and lower-1-alpha power indicated that the power attenuation after the combined intake of MDMA and THC was less than the sum of each drug alone. For the lower-2-alpha band, the intake of MDMA or THC alone did not significantly affect power, but the intake of combined MDMA and THC significantly decreased lower-2-alpha power. The present findings indicate that the combined intake of MDMA and THC, but not of MDMA and alcohol, affects ongoing EEG oscillations differently than the sum of either one drug alone. Changes in ongoing EEG oscillations may be related to the impaired task performance that has often been reported after drug intake.