This is the fourth of eight stories in our Web feature on self-experimenters.

The last time Olivier Ameisen formally practiced medicine was in the early summer of 1997. After two decades in the field, the French-born physician, then running a clinic on Manhattan's Upper East Side, abruptly rang up his secretary one morning and told her to clear his schedule.  She laughed in disbelief when he explained why. He was ill, he told her; he was an alcoholic, and he was afraid his drinking might interfere with his patients' care.

Anyone familiar with his resume would have responded the same way. Ameisen was a stellar medical student at the University of Paris—which he entered at the age of 16. Moving to the U.S., he began a fellowship in 1983 at New York–Presbyterian Hospital in Manhattan, swiftly becoming an attending physician there in 1986. (The same year, he added teaching appointments at the hospital-affiliated Weill Cornell Medical College of Cornell University.)

But things began to sour in 1994, when the then 41-year-old bachelor opened a private practice. Although the venture was initially successful—he broke even in four months instead of the usual two years—he became gripped by an irrational fear that he might not be able to provide for a future family. "That's when I started binging at home," says Ameisen, now 54. As time went by, "my fear," he says, "was to be drunk and have a patient call me and say, 'I have chest pain,' and have me tell him, 'Okay, go play tennis.'"

After putting his practice on hold, Ameisen spent nine months over two years in various rehab clinics trying to quell his alcohol cravings, or "motivations," as he calls them. He gave Alcoholics Anonymous a shot—or more like a round of shots; he estimates that in a single year he went to 700 meetings per year for seven years, as often as four a day. He also tried naltrexone and acamprosate, the only two drugs approved by the U.S. Food & Drug Administration to treat alcohol dependency, without success.

Finally, convalescing in Paris in 2001 (where he went to be close to his parents and relatives), he read about a study of a muscle relaxant that had stifled the cravings of a cocaine addict. The drug, baclofen, had also shown efficacy against anxiety and depression. Eager to try it, he prescribed a high dosage for himself. Within a few weeks of starting the regimen, his craving for drink evaporated. Eleven months into his self-experiment, he published a case study of his self-treatment in the journal Alcohol and Alcoholism, and he is now writing a book called The End of My Addiction, chronicling his successful journey.

Researchers believe that baclofen may increase the brain's levels of the neurotransmitter GABA (gamma-aminobutyric acid), involved in regulating the desire for addictive substances, by stimulating a subset of GABA receptors. But, contrary to Ameisen's experience, a recent double-blind study of 80 alcoholics at the University of North Carolina  School of Medicine in Chapel Hill found no difference in outcome between those taking baclofen or a placebo. Ameisen points out, however, that the dosage of 30 milligrams a day given to study participants was far lower than his up to 270-milligram daily dose, which studies had shown people could tolerate without displaying side effects such as somnolence and muscle weakness.

"The story on baclofen is really still out," says James C. Garbutt, a U.N.C. psychiatry professor and senior investigator on the study. He notes that the drug may reduce the anxiety and insomnia that often accompany alcohol withdrawal, which might ease the transition to sobriety, but adds that researchers cannot accurately predict who might benefit from the drug absent a larger study.

Still, Ameisen insists that for him the drug was a lifesaver. Now, instead of downing a quart and a half of Scotch a day, he takes as little as 70 milligrams of baclofen. He is contemplating a return to medicine, he says, but for now he takes satisfaction in corresponding with addiction researchers from his Paris apartment and encouraging them to conduct further clinical trials of baclofen.

"I know that case reports are there" on baclofen's efficacy, Ameisen notes. "But, even if you have 10 case reports, that's no better than one."