Human ecstasy (MDMA) polydrug users have altered brain activation during semantic processin

Studies on 3,4-methylenedioxymethamphetamine [MDMA] polydrug users have shown that these individuals have a verbal memory performance that is statistically significantly lower than that of control subjects. The purpose of this study was to examine the association of lifetime ecstasy use with semantic memory performance and brain activation in ecstasy polydrug users. 23 abstinent ecstasy polydrug users, and 11 controls were observed during this study. Each individual performed a two-part functional resonance imaging semantic encoding and recognition task. This was done to isolate brain regions that were activated during each somantic task. Several animal studies have shown degeneration of presynaptic axon terminals as well as serotonin depletion after neurotoxic regimens of MDMA. Studies of human recreational ecstasy use, in the past, have shown that polydrug use was more common than ecstasy alone. Studies showed that abstinent MDMA users exhibited a reduced memory for up to two years after the termination of use. It was repeatedly found that lower verbal memory was associated with MDMA, suggesting that verbal memory may be one of the most sensitive neurocognitive markers for MDMA effects. During behavioral analysis for the recognition portion of a task, time and accuracy of recognition were recorded. Since evidence found prior to this study, found that MDMA exposure is associated with altered verbal memory performance; the associations of lifetime MDMA use with focus on the accuracy during the semantic recognition task were examined more closely. The study was able to conclude that ecstasy polydrug users had a greater activation in semantic processing regions during a semantic task. In the end, When these results were compared to those of the control group, the data suggested that there may be a compensatory mechanism where greater neuronal activity is necessary in ecstasy polydrug users to preserve the same level of performance.  

Source: 

Psychopharmacology (Berl). 2013 May;227(1):41-54. doi: 10.1007/s00213-012-2936-1. Epub 2012 Dec 16.

Human ecstasy (MDMA) polydrug users have altered brain activation during semantic processing.

Watkins TJ, Raj V, Lee J, Dietrich MS, Cao A, Blackford JU, Salomon RM, Park S, Benningfield MM, Di Iorio CR, Cowan RL.

Vanderbilt Addiction Center, Vanderbilt University School of Medicine, Nashville, TN 37212, USA. tristan.j.watkins@vanderbilt.edu