"This phenomenon helps explain why addiction is a chronic, relapsing disease," says NIDA Director Dr. Alan I. Leshner. "Craving is a powerful force for cocaine addicts to resist, and the finding that it persists long after last drug use must be considered in tailoring treatment programs."
The research team, which included Drs. Jeff Grimm, Bruce Hope, Roy Wise and Yavin Shaham, published its findings in the July 12, 2001, issue of Nature.
In the study, the scientists found that sensitivity to drug-associated environmental cues that often accompany drug craving and relapse increased over a 60-day withdrawal period. Cocaine craving was inferred from the behavior of rats trained to press a lever to receive intravenous cocaine injections. Once the animals had learned to associate the lever-pressing with receiving cocaine, they were tested under conditions where they could continue to press the lever, but no longer received cocaine.
In humans, drug-associated environmental cues often stimulate cocaine craving and accompany relapse to drug-using behavior. The NIDA investigators wrote in their report to Nature that "the data from this study suggest that an individual is most vulnerable to relapse to cocaine use well beyond the acute drug withdrawal phase."
The National Institute on Drug Abuse is a component of the National Institutes of Health, U.S. Department of Health and Human Services. NIDA supports more than 85 percent of the world's research on the health aspects of drug abuse and addiction. The Institute carries out a large variety of programs to ensure the rapid dissemination of research information and its implementation in policy and practice. Fact sheets on the health effects of drugs of abuse and other topics can be ordered free of charge in English and Spanish through NIDA Infofax at 1-888-NIH-NIDA (644-6432) or 1-888-TTY-NIDA (889-6432) for the deaf. These fact sheets and further information on NIDA research and other activities can be found on the NIDA home page at http://www.drugabuse.gov.