title: Verbal Memory Impairment in Polydrug Ecstasy Users: A Clinical Perspective.
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 null hypothesis. History of use was not predictive of memory impairment. During MDMA intoxication of E-users, verbal memory was impaired.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, The Netherlands.
authors.forename: Kim P C
authors.initials: KP
authors.lastname: Kuypers
authors.affiliation: Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, The Netherlands.
authors.forename: Eef L
authors.initials: EL
authors.lastname: Theunissen
authors.affiliation: Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, The Netherlands.
authors.forename: Janelle H P
authors.initials: JH
authors.lastname: van Wel
authors.affiliation: Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, The Netherlands.
authors.forename: Elizabeth B
authors.initials: EB
authors.lastname: de Sousa Fernandes Perna
authors.affiliation: Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, The Netherlands.
authors.forename: Anke
authors.initials: A
authors.lastname: Linssen
authors.affiliation: Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, The Netherlands.
authors.forename: Anke
authors.initials: A
authors.lastname: Sambeth
authors.affiliation: Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, The Netherlands.
authors.forename: Benjamin G
authors.initials: BG
authors.lastname: Schultz
authors.affiliation: Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, The Netherlands.
authors.forename: Johannes G
authors.initials: JG
authors.lastname: Ramaekers
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D018849:Controlled Clinical Trials as Topic; D005260:Female; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000139:chemically induced*; D018817:N-Methyl-3,4-methylenedioxyamphetamine / Q000633:toxicity*; D014706:Verbal Learning / Q000187:drug effects; D055815:Young Adult
chemical_list: D018817:N-Methyl-3,4-methylenedioxyamphetamine