title: Prospective memory deficits in illicit polydrug users are associated with the average long-term typical dose of ecstasy typically consumed in a single session.
abstract: BACKGROUND
  Neuroimaging evidence suggests that ecstasy-related reductions in SERT densities relate more closely to the number of tablets typically consumed per session rather than estimated total lifetime use. To better understand the basis of drug related deficits in prospective memory (p.m.) we explored the association between p.m. and average long-term typical dose and long-term frequency of use.
  
  
  METHODS
  Study 1: Sixty-five ecstasy/polydrug users and 85 nonecstasy users completed an event-based, a short-term and a long-term time-based p.m. task. Study 2: Study 1 data were merged with outcomes on the same p.m. measures from a previous study creating a combined sample of 103 ecstasy/polydrug users, 38 cannabis-only users, and 65 nonusers of illicit drugs.
  
  
  RESULTS
  Study 1: Ecstasy/polydrug users had significant impairments on all p.m. outcomes compared with nonecstasy users. Study 2: Ecstasy/polydrug users were impaired in event-based p.m. compared with both other groups and in long-term time-based p.m. compared with nonillicit drug users. Both drug using groups did worse on the short-term time-based p.m. task compared with nonusers. Higher long-term average typical dose of ecstasy was associated with poorer performance on the event and short-term time-based p.m. tasks and accounted for unique variance in the two p.m. measures over and above the variance associated with cannabis and cocaine use.
  
  
  CONCLUSIONS
  The typical ecstasy dose consumed in a single session is an important predictor of p.m. impairments with higher doses reflecting increasing tolerance giving rise to greater p.m. impairment.
authors.affiliation: School of Psychology.
authors.forename: Denis T
authors.initials: DT
authors.lastname: Gallagher
authors.affiliation: Division of Psychology, Nottingham Trent University.
authors.forename: Florentia
authors.initials: F
authors.lastname: Hadjiefthyvoulou
authors.affiliation: School of Psychology.
authors.forename: John E
authors.initials: JE
authors.lastname: Fisk
authors.affiliation: School of Natural Sciences and Psychology, Liverpool John Moores University.
authors.forename: Catharine
authors.initials: C
authors.lastname: Montgomery
authors.affiliation: School of Psychology.
authors.forename: Sarita J
authors.initials: SJ
authors.lastname: Robinson
authors.affiliation: School of Psychology.
authors.forename: Jeannie
authors.initials: J
authors.lastname: Judge
mesh_terms: D000328:Adult; D002188:Cannabis / Q000633:toxicity; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory / Q000187:drug effects; D061212:Memory, Episodic; D018817:N-Methyl-3,4-methylenedioxyamphetamine / Q000008:administration & dosage / Q000633:toxicity*; D055815:Young Adult
chemical_list: D018817:N-Methyl-3,4-methylenedioxyamphetamine