Kicking Psychological Dependency

[Martha_05]

(This article belongs in the health section, but since there isn't one, it will reside here)

DISCOVER Vol. 20 No. 8 (August 1999)
Table of Contents

Kicking Psychological Dependency

Dopamine makes you feel good and some people go to great lengths to get more. Ravers take Ecstasy and addicts snort cocaine just to tickle their dopamine receptors. One of the biggest obstacles to getting off drugs, former abusers say, is psychological dependency on the dopamine kick.

French researchers think they have the answer. Pierre Sokoloff of the French Institute of Health and Medical Research has found that a compound called BP897 fits right into the dopamine receptor and stops rats from acting like they need a fix. Sokoloff believes that while BP897 does nothing to stop physical addiction, it may someday help people break the habit of drug taking.

The link between drugs and dopamine isn't direct. The body is always producing small amounts of dopamine. Drugs like cocaine block the channels that suck extra dopamine back into the nerve cell. This creates a short-term high because the cell is flooded with dopamine that's not getting drained away again. However, if dopamine cleanup is repeatedly blocked through sustained drug use, the body can assume that it's making too much and stops producing natural dopamine, or kill off some of the receptors. Addicts have to take more and more drugs to stay happy.

Sokoloff trained rats addicted to cocaine to respond, like Pavlov's dogs, to a signal the same way they'd respond to a hit of cocaine. Sokoloff saw this as a model of how people's environment influences their drug-taking habits. If being in a bar reminds a drinker of how good a beer tastes, or being around cigarettes makes smokers want to smoke, the light coming on reminded the rats of how good the cocaine felt. They'd press a lever in the cage just to turn on the light, if cocaine wasn't available.

Then the rats were given doses of BP897. The chemical mimics dopamine's effects, but only partially, so the receptors get neither too much stimulation nor not enough. The mixture kept the rats from asking for cocaine when they saw the light. There are no side effects, say the researchers, except that the rats stopped wanting cocaine just from being around things that reminded them of the high.

The researchers at the French Institute of Health and Medical Research in believe BP897 may work against other kinds of drugs, too. Receptors are thickly clustered in a nerve knot in the center of the brain, just above the ears, which has long been known to harbor the center of dependence. Hopefully BP897 would blind addicts to the cues around them that said, how about a line? The effects of BP879 may not be dramatic enough to work against physical addiction, but it could help people who are addicted psychologically, such as tobacco smokers who can't quit because they need something to do, or marijuana smokers, who aren't physically addicted but still can't seem to stop.

—Martha Heil
Posted 7/29/1999