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Verbal Memory Impairment in Polydrug Ecstasy Users: A Clinical Perspective.

Kuypers KP, Theunissen EL, van Wel JH, de Sousa Fernandes Perna EB, Linssen A, Sambeth A, Schultz BG, Ramaekers JG - PLoS ONE (2016)

Bottom Line: Data were analyzed using linear mixed-effects models, Bayes factor, and logistic regressions.Findings were that verbal memory performance of placebo-treated E-users did not differ from that of controls, and there was substantial evidence in favor of the hypothesis.This suggests that use of Ecstasy/MDMA does not lead to clinically deficient memory performance in the long term.

View Article: PubMed Central - PubMed

Affiliation: Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, The Netherlands.

ABSTRACT

Background: Ecstasy use has been associated with short-term and long-term memory deficits on a standard Word Learning Task (WLT). The clinical relevance of this has been debated and is currently unknown. The present study aimed at evaluating the clinical relevance of verbal memory impairment in Ecstasy users. To that end, clinical memory impairment was defined as decrement in memory performance that exceeded the cut-off value of 1.5 times the standard deviation of the average score in the healthy control sample. The primary question was whether being an Ecstasy user (E-user) was predictive of having clinically deficient memory performance compared to a healthy control group.

Methods: WLT data were pooled from four experimental MDMA studies that compared memory performance during placebo and MDMA intoxication. Control data were taken from healthy volunteers with no drug use history who completed the WLT as part of a placebo-controlled clinical trial. This resulted in a sample size of 65 E-users and 65 age- and gender-matched healthy drug-naïve controls. All participants were recruited by similar means and were tested at the same testing facilities using identical standard operating procedures. Data were analyzed using linear mixed-effects models, Bayes factor, and logistic regressions.

Results: Findings were that verbal memory performance of placebo-treated E-users did not differ from that of controls, and there was substantial evidence in favor of the hypothesis. History of use was not predictive of memory impairment. During MDMA intoxication of E-users, verbal memory was impaired.

Conclusion: The combination of the acute and long-term findings demonstrates that, while clinically relevant memory impairment is present during intoxication, it is absent during abstinence. This suggests that use of Ecstasy/MDMA does not lead to clinically deficient memory performance in the long term. Additionally, it has to be investigated whether the current findings apply to more complex cognitive measures in diverse 'user categories' using a combination of genetics, imaging techniques and neuropsychological assessments.

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Related in: MedlinePlus

The median (red line), 25th and 75th percentiles (box edges), range excluding outliers (whiskers), and outliers (red +) of the Total Immediate Recall (IR) Score (upper graph) and Delayed Recall (DR) Score (lower graph) of Controls, and Ecstasy users (E-Users) in the placebo condition and MDMA condition.
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pone.0149438.g001: The median (red line), 25th and 75th percentiles (box edges), range excluding outliers (whiskers), and outliers (red +) of the Total Immediate Recall (IR) Score (upper graph) and Delayed Recall (DR) Score (lower graph) of Controls, and Ecstasy users (E-Users) in the placebo condition and MDMA condition.

Mentions: The LMEM yielded no significant differences between E-users and healthy controls on measures of immediate recall [F (1, 9.08) = 0.24, p = .64, η2G = .01] and delayed recall [F (1, 7.65) = 0.02, p = .89, η2G = .0004] (Fig 1, placebo scores). To test whether there was evidence in favor of the hypothesis for differences between E-users and controls, the Bayes factor was calculated. There was substantial evidence for the hypothesis (see Jeffreys, 1961) for the immediate recall (BF01 = 4.36 ± 0%) and delayed recall (BF01 = 4.55 ± 0%) tasks. These results indicate that long-term MDMA use does not impair verbal memory ability.


Verbal Memory Impairment in Polydrug Ecstasy Users: A Clinical Perspective.

Kuypers KP, Theunissen EL, van Wel JH, de Sousa Fernandes Perna EB, Linssen A, Sambeth A, Schultz BG, Ramaekers JG - PLoS ONE (2016)

The median (red line), 25th and 75th percentiles (box edges), range excluding outliers (whiskers), and outliers (red +) of the Total Immediate Recall (IR) Score (upper graph) and Delayed Recall (DR) Score (lower graph) of Controls, and Ecstasy users (E-Users) in the placebo condition and MDMA condition.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4764468&req=5

pone.0149438.g001: The median (red line), 25th and 75th percentiles (box edges), range excluding outliers (whiskers), and outliers (red +) of the Total Immediate Recall (IR) Score (upper graph) and Delayed Recall (DR) Score (lower graph) of Controls, and Ecstasy users (E-Users) in the placebo condition and MDMA condition.
Mentions: The LMEM yielded no significant differences between E-users and healthy controls on measures of immediate recall [F (1, 9.08) = 0.24, p = .64, η2G = .01] and delayed recall [F (1, 7.65) = 0.02, p = .89, η2G = .0004] (Fig 1, placebo scores). To test whether there was evidence in favor of the hypothesis for differences between E-users and controls, the Bayes factor was calculated. There was substantial evidence for the hypothesis (see Jeffreys, 1961) for the immediate recall (BF01 = 4.36 ± 0%) and delayed recall (BF01 = 4.55 ± 0%) tasks. These results indicate that long-term MDMA use does not impair verbal memory ability.

Bottom Line: Data were analyzed using linear mixed-effects models, Bayes factor, and logistic regressions.Findings were that verbal memory performance of placebo-treated E-users did not differ from that of controls, and there was substantial evidence in favor of the hypothesis.This suggests that use of Ecstasy/MDMA does not lead to clinically deficient memory performance in the long term.

View Article: PubMed Central - PubMed

Affiliation: Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, The Netherlands.

ABSTRACT

Background: Ecstasy use has been associated with short-term and long-term memory deficits on a standard Word Learning Task (WLT). The clinical relevance of this has been debated and is currently unknown. The present study aimed at evaluating the clinical relevance of verbal memory impairment in Ecstasy users. To that end, clinical memory impairment was defined as decrement in memory performance that exceeded the cut-off value of 1.5 times the standard deviation of the average score in the healthy control sample. The primary question was whether being an Ecstasy user (E-user) was predictive of having clinically deficient memory performance compared to a healthy control group.

Methods: WLT data were pooled from four experimental MDMA studies that compared memory performance during placebo and MDMA intoxication. Control data were taken from healthy volunteers with no drug use history who completed the WLT as part of a placebo-controlled clinical trial. This resulted in a sample size of 65 E-users and 65 age- and gender-matched healthy drug-naïve controls. All participants were recruited by similar means and were tested at the same testing facilities using identical standard operating procedures. Data were analyzed using linear mixed-effects models, Bayes factor, and logistic regressions.

Results: Findings were that verbal memory performance of placebo-treated E-users did not differ from that of controls, and there was substantial evidence in favor of the hypothesis. History of use was not predictive of memory impairment. During MDMA intoxication of E-users, verbal memory was impaired.

Conclusion: The combination of the acute and long-term findings demonstrates that, while clinically relevant memory impairment is present during intoxication, it is absent during abstinence. This suggests that use of Ecstasy/MDMA does not lead to clinically deficient memory performance in the long term. Additionally, it has to be investigated whether the current findings apply to more complex cognitive measures in diverse 'user categories' using a combination of genetics, imaging techniques and neuropsychological assessments.

Show MeSH
Related in: MedlinePlus