Systematic review of prospective studies investigating "remission" from amphetamine, cannabis, cocaine or opioid dependence.
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.
Calabria
Bianca
B
National Drug and Alcohol Research Centre, University of New South Wales, Sydney, NSW 2052, Australia. b.calabria@unsw.edu.au
Degenhardt
Louisa
L
Briegleb
Christina
C
Vos
Theo
T
Hall
Wayne
W
Lynskey
Michael
M
Callaghan
Bridget
B
Rana
Umer
U
McLaren
Jennifer
J
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