What Addicts Need

• Delayed discounting, the willingness to put off present gratification in the interest of a bigger long-term reward. Addicts always take the immediate reward.

• Reflection impulsivity, a measure of how much information is required to make a decision. Addicts typically act without processing all the available information.

• Intentional action, the ability to consciously stop a behavior that has become automatic.

To measure this, NIDA researchers had addicts watch a screen and push one of two buttons, according to whether a light has flashed on the left or right side—except when the light was accompanied by a tone. After several rounds, pushing the button becomes an automatic response that has to be overridden consciously, and addicts were much less able to do this than non-addicts. As scientists have known since the 1980s, the neurons that control movement are activated even before a person is aware of the intention. Now researchers have identified the part of the brain—the fronto-median cortex—that is activated when someone stops himself from executing such automatic behaviors. This is as close as we have got to finding the seat of willpower in the brain. Put an addict in an fMRI machine, and you can observe reduced activity in the fronto-median cortex. But a drug called Provigil, which is ordinarily used to treat narcolepsy, stimulates that part of the brain and is now being tested as a treatment for amphetamine addiction. "The idea that we can restore 'self-control' or 'free will' with medication is a very, very exciting one," says Vocci of NIDA. "It could be paradigm shifting. But we need more studies to see how consistently that impacts recovery."

That is a useful caution; these drugs are new and their mechanisms are still only partially understood. The brain has a way of resisting attempts to tinker with its chemistry. The discovery in 1960 that Parkinsonism was caused by a deficiency of dopamine quickly led to the use of synthetic dopamine precursors, such as L-dopa, which relieved the symptoms at first, but were not the long-term cure patients had hoped for.

A more straightforward approach to treating, or preventing, addiction is to block the action of the drug directly. If it doesn't feel good, the thinking goes, you won't do it. Naltrexone, a pill that has been around for a decade, works that way against alcohol, but an addict intent on getting high can just skip his dose. The solution to that problem is Vivitrol, a longer-lasting, injectable form of Naltrexone, which came on the market in 2006. Vivitrol, the drug Annie Fuller took, does not enhance self-control or stop the craving for liquor, but it does block liquor's effects. The day Fuller got her shot, her leg swelled to twice its normal size. The swelling subsided a day or two later, but the next few weeks were a torment of sweating, shaking, vomiting and tears—side effects that came from both Vivitrol and alcohol withdrawal. At times she couldn't walk and needed help to use the bathroom. The only thing that kept her from drinking was the knowledge that she could not get drunk. "The shot just took the relapse option off the table," she says. She got the same injection every month for the rest of the year, suffering a little less each time, and she is now off the medication and sober.