Cocaine Cravings Increase Over Time

July 11, 2001 -- Cocaine addicts’ drug cravings may increase, rather than decrease, over time after cocaine use has stopped, finds a study on rats by the National Institute on Drug Abuse published in the July 12 issue of Nature.

Researchers say rats addicted to cocaine are about four times as persistent in trying to obtain a dose of the drug 60 days after quitting than they were after one drug-free day. Experts say this finding, if applicable to humans, could have huge implications for treatment of cocaine addiction.

“It’s one of those things where absence makes the heart grow fonder,” said Jeffrey Grimm, first author of the study, released today, and experimental psychologist with NIDA, which is based in Bethesda, Md. “The importance of this is that a lot of people have the idea that cravings get lower over time.

“We were kind of expecting to see cravings diminish over time and were surprised to see them progressively increase.”

Cues Are Key

In the experiment, researchers focused on “cues,” or reminders of the drug. For the rats, the cue was a red light that turned on when researchers made the drug available. For humans, cues can range from seeing a bag of cocaine to something as simple as holding a rolled-up dollar bill.

When addicts receive the cue, their cravings for cocaine intensify.

Dr. Herbert Kleber, director of the division of substance abuse at the Columbia University College of Physicians and Surgeons in New York, said the new study reinforces findings drug craving from a study he authored in 1986, based on testing of humans.

“[These studies] emphasize the need for intensive relapse training so addicts can cope and, equally important, the development of medications that will either decrease or block these feelings,” Kleber said.

“This study emphasizes the importance of treatment that is intensive enough and long enough to deal with heightened craving, and it points out the fallacy of many managed-care programs that don’t permit patients to be in treatment long enough to get help with this.”

Grimm agreed. “In terms of implications for treatment, if someone goes into treatment for two months and comes out, they might be coming out when they are most sensitive to drug cues.”