Level of use of 3,4-methylenedioxymethamphetamine (MDMA or Ecstasy) in humans correlates with EEG power and coherence

Rationale: Despite animal studies implicating 3,4-methylenedioxymethampheta mine (MDMA or Ecstasy) in serotonergic neurotoxicity, there is little direc t evidence of changes in neural function in humans who use MDMA as a recrea tional drug. Objective: The present study investigated whether there is a c orrelation between quantitative EEG variables (spectral power and coherence ) and cognitive/mood variables, and level of prior use of MDMA. Methods: Tw enty-three recreational MDMA users were studied. Resting EEG was recorded w ith eyes closed, using a 128-electrode geodesic net system, from which spec tral power, peak frequency and coherence levels were calculated. Tests of i ntelligence (NART), immediate and delayed memory, frontal function (card so rt task), and mood (BDI and PANAS scales) were also administered. Pearson c orrelation analyses were used to examine the relationship between these mea sures and the subject's consumption of MDMA during the previous 12-month pe riod. Partial correlation was used to control for the use of other recreati onal drugs. Results: MDMA use was positively correlated with absolute power in the alpha (8-12 Hz) and beta (12-20 Hz) frequency bands, but not with t he delta (1-3 Hz) or theta (4-7 Hz) bands. MDMA use was negatively correlat ed with EEG coherence, a measure of synchrony between paired cortical locat ions, in posterior brain sites thought to overly the main visual associatio n pathways of the occipito-parietal region. MDMA use did not correlate sign ificantly with any of the mood/cognitive measures except the card sort task , with which it was weakly negatively correlated. Conclusions: Alpha power has been shown to be inversely related to mental function and has been used as an indirect measure of brain activation in both normal and abnormal sta tes. Reduced coherence levels have been associated with dysfunctional conne ctivity in the brain in disorders such as dementia, white-matter disease an d normal aging. Our results may indicate altered brain function correlated with prior MDMA use, and show that electroencephalography may be a cheap an d effective tool for examining neurotoxic effects of MDMA and other drugs.