ADDICTED: WHY DO PEOPLE GET HOOKED?

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The more science unmasks the powerful biology that underlies addiction, the brighter the prospects for treatment become. For instance, the discovery by Fowler and her team that a chemical that inhibits the mopping-up enzyme MAO B may play a role in cigarette addiction has already opened new possibilities for therapy. A number of well-tolerated MAO B-inhibitor drugs developed to treat Parkinson's disease could find a place in the antismoking arsenal. Equally promising, a Yale University team led by Eric Nestler and David Self has found that another type of compound--one that targets the dopamine receptor known as D1--seems to alleviate, at least in rats, the intense craving that accompanies withdrawal from cocaine. One day, suggests Self, a D1 skin patch might help cocaine abusers kick their habit, just as the nicotine patch attenuates the desire to smoke.

Like methadone, the compound that activates D1 appears to be what is known as a partial agonist. Because such medications stimulate some of the same brain pathways as drugs of abuse, they are often addictive in their own right, though less so. And while treating heroin addicts with methadone may seem like a cop-out to people who have never struggled with a drug habit, clinicians say they desperately need more such agents to tide addicts--particularly cocaine addicts--over the first few months of treatment, when the danger of relapse is highest.

Realistically, no one believes better medications alone will solve the drug problem. In fact, one of the most hopeful messages coming out of current research is that the biochemical abnormalities associated with addiction can be reversed through learning. For that reason, all sorts of psychosocial interventions, ranging from psychotherapy to 12-step programs, can and do help. Cognitive therapy, which seeks to supply people with coping skills (exercising after work instead of going to a bar, for instance), appears to hold particular promise. After just 10 weeks of therapy, before-and-after pet scans suggest, some patients suffering from obsessive-compulsive disorder (which has some similarities with addiction) manage to resculpt not only their behavior but also activity patterns in their brain.

In late 20th century America, where drugs of abuse are being used on an unprecedented scale, the mounting evidence that treatment works could not be more welcome. Until now, policymakers have responded to the drug problem as though it were mostly a criminal matter. Only a third of the $15 billion the U.S. earmarks for the war on drugs goes to prevention and treatment. "In my view, we've got things upside down," says Dr. David Lewis, director of the Center for Alcohol and Addiction Studies at Brown University School of Medicine. "By relying so heavily on a criminalized approach, we've only added to the stigma of drug abuse and prevented high-quality medical care."