title: Systematic review of prospective studies investigating "remission" from amphetamine, cannabis, cocaine or opioid dependence.
abstract: OBJECTIVE
  To review and summarize existing prospective studies reporting on remission from dependence upon amphetamines, cannabis, cocaine or opioids.
  
  
  METHODS
  Systematic searches of the peer-reviewed literature were conducted to identify prospective studies reporting on remission from amphetamines, cannabis, cocaine or opioid dependence. Searches were limited to publication between 1990 and 2009. Reference lists of review articles and important studies were searched to identify additional studies. Remission was defined as no longer meeting diagnostic criteria for drug dependence or abstinence from drug use; follow-up periods of at least three years were investigated. The remission rate was estimated for each drug type, allowing pooling across studies with varying follow-up times.
  
  
  RESULTS
  There were few studies examining the course of psychostimulant dependence that met inclusion criteria (one for amphetamines and four for cocaine). There were ten studies of opioid and three for cannabis dependence. Definitions of remission varied and most did not clearly assess remission from dependence. Amphetamine dependence had the highest remission rate (0.4477; 95%CI 0.3991, 0.4945), followed by opioid (0.2235; 95%CI 0.2091, 0.2408) and cocaine dependence (0.1366; 95%CI 0.1244, 0.1498). Conservative estimates of remission rates followed the same pattern with cannabis dependence (0.1734; 95%CI 0.1430, 0.2078) followed by amphetamine (0.1637; 95%CI 0.1475, 0.1797), opioid (0.0917; 95%CI 0.0842, 0.0979) and cocaine dependence (0.0532; 95%CI 0.0502, 0.0597).
  
  
  CONCLUSIONS
  The limited prospective evidence suggests that "remission" from dependence may occur relatively frequently but rates may differ across drugs. There is very little research on remission from drug dependence; definitions used are often imprecise and inconsistent across studies and there remains considerable uncertainty about the longitudinal course of dependence upon these most commonly used illicit drugs.
authors.affiliation: National Drug and Alcohol Research Centre, University of New South Wales, Sydney, NSW 2052, Australia. b.calabria@unsw.edu.au
authors.forename: Bianca
authors.initials: B
authors.lastname: Calabria
authors.forename: Louisa
authors.initials: L
authors.lastname: Degenhardt
authors.forename: Christina
authors.initials: C
authors.lastname: Briegleb
authors.forename: Theo
authors.initials: T
authors.lastname: Vos
authors.forename: Wayne
authors.initials: W
authors.lastname: Hall
authors.forename: Michael
authors.initials: M
authors.lastname: Lynskey
authors.forename: Bridget
authors.initials: B
authors.lastname: Callaghan
authors.forename: Umer
authors.initials: U
authors.lastname: Rana
authors.forename: Jennifer
authors.initials: J
authors.lastname: McLaren
mesh_terms: D019969:Amphetamine-Related Disorders / Q000453:epidemiology / Q000534:rehabilitation*; D016739:Behavior, Addictive / Q000523:psychology*; D019970:Cocaine-Related Disorders / Q000453:epidemiology / Q000534:rehabilitation*; D015331:Cohort Studies; D006801:Humans; D002189:Marijuana Abuse / Q000453:epidemiology / Q000534:rehabilitation*; D009293:Opioid-Related Disorders / Q000453:epidemiology / Q000534:rehabilitation*; D011446:Prospective Studies; D012074:Remission Induction; D012075:Remission, Spontaneous; D013997:Time Factors