title: Self-reported prevalence of dependence of MDMA compared to cocaine, mephedrone and ketamine among a sample of recreational poly-drug users.
abstract: BACKGROUND
  Evidence regarding MDMA (ecstasy) dependence and the most suitable criteria for its assessment are controversial. This study aimed to assess the prevalence of last year symptoms of dependence upon MDMA compared to cocaine, mephedrone and ketamine among a large global non-treatment seeking sample.
  
  
  METHODS
  A cross-sectional anonymous online survey was promoted by a UK-based dance music website between 15 November 2010 and 1 January 2011. Endorsement of DSM-IV (Diagnostic and Statistical Manual of Mental Disorders) dependence criteria was sought from all last year users of MDMA, cocaine, mephedrone and ketamine. Reporting ≥3 dependence symptoms was indicative of dependence. Logistic regression models with Generalized Estimating Equations were used to compare dependence symptoms between groups.
  
  
  RESULTS
  MDMA users were more likely to report ≥3 DSM-IV dependence symptoms compared to users of cocaine (odds ratio OR 0.81, 95% confidence interval CI 0.71-0.93), mephedrone (OR 0.91, 95%CI 0.78-1.06) and ketamine (OR 0.52, 95%CI 0.44-0.62) (p<0.001). MDMA users were less likely to report desire to use less or get help compared to users of other substances (p<0.001). MDMA got the highest rating of pleasurable high (mean 8.2±1.7) and lowest rating for risk of harm (mean 2.7±2.4).
  
  
  CONCLUSIONS
  Our results highlight the self-reported dependence potential of MDMA but low desire to use less or get help. MDMA's pleasurable effects may compensate for drug-related problems and, therefore, DSM-IV criteria may not be suitable for assessing MDMA dependence. Further research is needed on the ability of DSM-V to assess MDMA dependence.
authors.affiliation: School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, Kuopio, Finland. Electronic address: hanna.uosukainen@uef.fi.
authors.forename: Hanna
authors.initials: H
authors.lastname: Uosukainen
authors.affiliation: School of Medicine, Psychiatry, Faculty of Health Sciences, University of Eastern Finland, Kuopio, Finland; Addiction Psychiatry Unit, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Tacke
authors.affiliation: South London and Maudsley NHS Trust/King's College London, London, UK; Global Drug Survey, London, UK.
authors.forename: Adam R
authors.initials: AR
authors.lastname: Winstock
mesh_terms: D000293:Adolescent; D000328:Adult; D019969:Amphetamine-Related Disorders / Q000453:epidemiology*; D019970:Cocaine-Related Disorders / Q000453:epidemiology*; D003430:Cross-Sectional Studies; D003625:Data Collection; D005260:Female; D006801:Humans; D007649:Ketamine / Q000009:adverse effects; D016015:Logistic Models; D008297:Male; D008694:Methamphetamine / Q000009:adverse effects / Q000031:analogs & derivatives; D018817:N-Methyl-3,4-methylenedioxyamphetamine / Q000009:adverse effects; D015995:Prevalence; D057566:Self Report; D019966:Substance-Related Disorders / Q000453:epidemiology*; D055815:Young Adult
chemical_list: D008694:Methamphetamine; D007649:Ketamine; C548233:mephedrone; D018817:N-Methyl-3,4-methylenedioxyamphetamine
keywords: Cocaine; Ketamine; MDMA; Mephedrone; Substance-related disorders