Do animal models provide a valid analogue for human drug lapse and relapse? Comment on Leri and Stewart (2002).

Prior research on animal models of drug relapse has demonstrated that passive exposure to an addictive substance following acquisition and extinction of drug self-administration has a "priming effect" on subsequent drug use. The validity of this animal analogue of human relapse can be criticized, however, because most human drug relapses are precipitated by the user's voluntary self-administration of a substance. The results of the present study by F. Leri and J. Stewart (2002) clearly show that if the initial heroin lapse is self-administered by rats, subsequent heroin seeking during the relapse test is significantly greater than if the heroin is externally administered. These results help bridge the gap between animal and human models of drug use and highlight the significance of both behavioral and environmental determinants of relapse.