title: Effects of ecstasy on cooperative behaviour and perception of trustworthiness: a naturalistic study.
abstract: BACKGROUND
  Acute recreational use of 3,4-methylenedioxymethamphetamine (MDMA; 'ecstasy') can promote pro-social effects which may alter interpersonal perceptions.
  
  
  OBJECTIVE
  To explore such effects, this study investigated whether acute recreational use of ecstasy was associated with changes in individual perception of trustworthiness of people's faces and co-operative behaviours.
  
  
  METHODS
  An independent group, repeated measures design was used in which 17 ecstasy users were tested on the night of drug use (day 0) and again three days later (day 3); 22 controls were tested on parallel days. On each day, participants rated the trustworthiness of 66 faces, carried out three co-operative behaviour tasks (public good; dictator; ultimatum game) and completed mood self-ratings.
  
  
  RESULTS
  Acute ecstasy use was associated with increased face trustworthiness ratings and increased cooperative behaviour on the dictator and ultimatum games; on day 3 there were no group differences on any task. Self-ratings showed the standard acute ecstasy effects (euphoria, energy, jaw clenching) with negative effects (less empathy, compassion, more distrust, hostility) emerging on day 3.
  
  
  CONCLUSIONS
  Our findings of increased perceived trustworthiness and co-operative behaviours following use of ecstasy suggest that a single dose of the drug enhances aspects of empathy. This may in turn contribute to its popularity as a recreational drug and potentially to its enhancement of the therapeutic alliance in psychotherapy.
authors.affiliation: Clinical Psychopharmacology Unit, University College London, London, UK.
authors.forename: L H
authors.initials: LH
authors.lastname: Stewart
authors.affiliation: Clinical Psychopharmacology Unit, University College London, London, UK.
authors.forename: B
authors.initials: B
authors.lastname: Ferguson
authors.affiliation: Clinical Psychopharmacology Unit, University College London, London, UK.
authors.forename: C J A
authors.initials: CJ
authors.lastname: Morgan
authors.affiliation: Clinical Psychopharmacology Unit, University College London, London, UK.
authors.forename: N
authors.initials: N
authors.lastname: Swaboda
authors.affiliation: Clinical Psychopharmacology Unit, University College London, London, UK.
authors.forename: L
authors.initials: L
authors.lastname: Jones
authors.affiliation: Clinical Psychopharmacology Unit, University College London, London, UK.
authors.forename: R
authors.initials: R
authors.lastname: Fenton
authors.affiliation: Imanova Centre for Imaging Sciences, London, UK Division of Brain Sciences, Imperial College London, London, UK.
authors.forename: M B
authors.initials: MB
authors.lastname: Wall
authors.affiliation: Clinical Psychopharmacology Unit, University College London, London, UK v.curran@ucl.ac.uk.
authors.forename: H V
authors.initials: HV
authors.lastname: Curran
mesh_terms: D000339:Affect / Q000187:drug effects; D016022:Case-Control Studies; D003299:Cooperative Behavior; D005149:Facial Expression; D005260:Female; D006801:Humans; D008297:Male; D018817:N-Methyl-3,4-methylenedioxyamphetamine / Q000494:pharmacology*; D012938:Social Perception; D035502:Trust / Q000523:psychology*; D055815:Young Adult
chemical_list: D018817:N-Methyl-3,4-methylenedioxyamphetamine
keywords: 3,4-methylenedioxymethamphetamine; Co-operation; acute; ecstasy; pro-social; psychological therapy; sub-acute; trust