title: Deficits of long-term memory in ecstasy users are related to cognitive complexity of the task.
abstract: BACKGROUND
  Despite animal evidence that methylenedioxymethamphetamine (ecstasy) causes lasting damage in brain regions related to long-term memory, results regarding human memory performance have been variable. This variability may reflect the cognitive complexity of the memory tasks. However, previous studies have tested only a limited range of cognitive complexity. Furthermore, comparisons across different studies are made difficult by regional variations in ecstasy composition and patterns of use.
  
  
  OBJECTIVE
  The objective of this study is to evaluate ecstasy-related deficits in human verbal memory over a wide range of cognitive complexity using subjects drawn from a single geographical population.
  
  
  METHODS
  Ecstasy users were compared to non-drug using controls on verbal tasks with low cognitive complexity (stem completion), moderate cognitive complexity (stem-cued recall and word list learning) and high cognitive complexity (California Verbal Learning Test, Verbal Paired Associates and a novel Verbal Triplet Associates test). Where significant differences were found, both groups were also compared to cannabis users.
  
  
  RESULTS
  More cognitively complex memory tasks were associated with clearer ecstasy-related deficits than low complexity tasks. In the most cognitively demanding task, ecstasy-related deficits remained even after multiple learning opportunities, whereas the performance of cannabis users approached that of non-drug using controls. Ecstasy users also had weaker deliberate strategy use than both non-drug and cannabis controls.
  
  
  CONCLUSIONS
  Results were consistent with the proposal that ecstasy-related memory deficits are more reliable on tasks with greater cognitive complexity. This could arise either because such tasks require a greater contribution from the frontal lobe or because they require greater interaction between multiple brain regions.
authors.affiliation: Department of Psychology, The Australian National University, Building 39, Canberra, ACT 0200, Australia. john.brown@anu.edu.au
authors.forename: John
authors.initials: J
authors.lastname: Brown
authors.forename: Elinor
authors.initials: E
authors.lastname: McKone
authors.forename: Jeff
authors.initials: J
authors.lastname: Ward
mesh_terms: D000293:Adolescent; D000328:Adult; D003071:Cognition / Q000187:drug effects*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D002189:Marijuana Abuse / Q000150:complications; D008568:Memory / Q000187:drug effects*; D018817:N-Methyl-3,4-methylenedioxyamphetamine / Q000633:toxicity*; D009483:Neuropsychological Tests; D012189:Retrospective Studies; D018490:Serotonin Agents / Q000633:toxicity*; D055815:Young Adult
chemical_list: D018490:Serotonin Agents; D018817:N-Methyl-3,4-methylenedioxyamphetamine