OPEN Foundation

C. Montgomery

MDMA and brain activity during neurocognitive performance: An overview of neuroimaging studies with abstinent ‘Ecstasy’ users

August 8, 2017 / MDMA, Papers, Psychology, Psychopharmacology, Publications, Safety / By / , , ,

Abstract

MDMA/Ecstasy has had a resurgence in popularity, with recent supplies comprising higher strength MDMA, potentially leading to increased drug-related harm. Neurocognitive problems have been widely reported in ecstasy users, equally some studies report null findings, and it remains unclear which factors underlie the development of neurocognitive impairments. This review covers the empirical research into brain activity during neurocognitive performance, using fMRI, fNIRS, and EEG. Our main conclusion is that chronic repeated use of recreational ecstasy can result in haemodynamic and electrophysiological changes that reflect recruitment of additional resources to perform cognitive tasks.

Findings are consistent with serotonergic system changes, although whether this reflects neurotoxicity or neuroadaptation, cannot be answered from these data. There is a degree of heterogeneity in the methodologies and findings, limiting the strengths of current conclusions. Future research with functional neuroimaging paired with molecular imaging, genetics or pharmacological challenges of the serotonin system may help to decipher the link between serotonergic and cognitive changes in ecstasy users.

Roberts, C. A., Quednow, B. B., Montgomery, C., & Parrott, A. C. (2017). MDMA and brain activity during neurocognitive performance: An overview of neuroimaging studies with abstinent ‘Ecstasy’users. Neuroscience & Biobehavioral Reviews. 10.1016/j.neubiorev.2017.07.015
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Meta-analysis of executive functioning in ecstasy/polydrug users

March 11, 2016 / MDMA, Neuroscience, Other disciplines, Other subjects, Papers, Psychiatry, Psychology, Publications, Safety, Sociology / By / , ,

Abstract

Ecstasy/3,4-methylenedioxymethamphetamine (MDMA) use is proposed to cause damage to serotonergic (5-HT) axons in humans. Therefore, users should show deficits in cognitive processes that rely on serotonin-rich, prefrontal areas of the brain. However, there is inconsistency in findings to support this hypothesis. The aim of the current study was to examine deficits in executive functioning in ecstasy users compared with controls using meta-analysis. We identified k = 39 studies, contributing 89 effect sizes, investigating executive functioning in ecstasy users and polydrug-using controls. We compared function-specific task performance in 1221 current ecstasy users and 1242 drug-using controls, from tasks tapping the executive functions – updating, switching, inhibition and access to long-term memory. The significant main effect demonstrated overall executive dysfunction in ecstasy users [standardized mean difference (SMD) = -0.18, 95% confidence interval (CI) -0.26 to -0.11, Z = 5.05, p < 0.001, I 2 = 82%], with a significant subgroup effect (χ 2 = 22.06, degrees of freedom = 3, p < 0.001, I 2 = 86.4%) demonstrating differential effects across executive functions. Ecstasy users showed significant performance deficits in access (SMD = -0.33, 95% CI -0.46 to -0.19, Z = 4.72, p < 0.001, I 2 = 74%), switching (SMD = -0.19, 95% CI -0.36 to -0.02, Z = 2.16, p < 0.05, I 2 = 85%) and updating (SMD = -0.26, 95% CI -0.37 to -0.15, Z = 4.49, p < 0.001, I 2 = 82%). No differences were observed in inhibitory control. We conclude that this is the most comprehensive analysis of executive function in ecstasy users to date and provides a behavioural correlate of potential serotonergic neurotoxicity.

Roberts, C. A., Jones, A., & Montgomery, C. (2016). Meta-analysis of executive functioning in ecstasy/polydrug users. Psychological medicine, 1-16. http://dx.doi.org/10.1017/S0033291716000258

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30 April - Q&A with Rick Strassman

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