"Acupuncture research is still in its infancy," Culliton says, "so we don't really know how it works. In addition to releasing endorphins, it also changes levels of hormones and liver enzymes. It's complicated. Personally, I believe that it boosts the body's innate ability to heal."

Chinese-Americans have used acupuncture since the first Chinese immigrants arrived in this country. But the needle therapy was unknown to most non-Asian Americans until 1971 when Richard Nixon became the first U.S. president to visit the People's Republic of China. During that visit, TV news programs broadcast astonishing footage of people having major surgery while fully conscious -- their only anesthesia being a few acupuncture needles. New York Times columnist James Reston accompanied Nixon and witnessed acupuncture anesthesia firsthand. As fate would have it, Reston needed an emergency appendectomy while in China. He decided to try acupuncture instead of narcotics to control his postsurgical pain. It worked, and Reston's praise for the needle therapy spurred tremendous interest in acupuncture.

The origins of acupuncture are lost to history, but legend has it that an ancient Chinese soldier suffered an illness his physicians could not cure. In battle, he was hit by an arrow, receiving a superficial wound. The wound healed, and oddly, so did his illness. Intrigued, Chinese physicians began recording the places -- or "points" -- around the body where stabbing wounds produced improbable healing. Their observations led to acupuncture and its offshoots: acupressure (which uses finger pressure instead of needles), shiatsu (Japanese massage on acupuncture points) and reflexology (acupressure massage of the feet or hands).

Chinese medicine postulates that acupuncture works by restoring healthy circulation of qi (pronounced "chee"), humans' invisible life force. Qi circulates around the body along meandering pathways called meridians. Like qi, the meridians are invisible and cannot be found by dissection. When illness blocks qi, acupuncture can help unblock it, which restores health.

Nonsense, say Western medical critics, who scoff at invisible meridians and qi as unscientific concepts. At worst, they say, acupuncture is a form of primitive superstition, and at best, it's nothing more than a placebo effect. In the words of Robert J. White, M.D., a professor of neurosurgery at Case Western Reserve University School of Medicine in Cleveland, acupuncture "has the same scientific validity as astrology or alchemy."

But according to studies by acupuncture researcher George A. Ulett, M.D., at the University of Missouri School of Medicine, acupuncture is neither alchemy nor placebo. Placebos produce benefits in about one-third of those who use them, Ulett explains, but most well-designed studies of acupuncture pain relief show effectiveness in the range of 55 to 85 percent.

"The evidence suggests that acupuncture works neuroelectrically," Ulett explains. "In my view, the meridians are not invisible. They are the motor nerves, the ones connected to the major muscle groups. Stimulating acupuncture points changes the flow of bioelectrical energy along these nerves and triggers the release of neurotransmitters, which produces its effects."

Acupuncture still has its critics. "Some won't accept anything that can't be fully explained in Western scientific terms," Culliton says. "and acupuncture still can't be, at least not yet."

The critics have a point. Over the years, quite a few studies have shown no benefit for true acupuncture over the "sham acupuncture" typically used as the control in recent experiments. Margolin, author of the cocaine study, thinks he knows why.

"It's quite possible that the 'sham' points some researchers used actually had some activity." Margolin eliminated this possibility in a study published last year that showed activity for the classic ear points used in addiction treatment, and no activity for specific sham points he investigated. He then used the "certified" sham points in his new study on cocaine addiction, confident that they really were sham points.

Questions remain about the methodology of acupuncture research, but in recent years, the critics' numbers have dwindled. "Lately, I've noticed greater acceptance of acupuncture by the medical community," Margolin observes. A key reason, he says, has been the increasing number of rigorous studies published in mainstream medical journals documenting its benefits.

Recently, in addition to the new study of addiction, there have been several meta-analyses of successful acupuncture treatment for temporomandibular joint dysfunction (TMJ), fibromyalgia, back pain and hives as well as studies showing its effectiveness on arthritis, asthma, diabetic nerve damage, headache, impotence, menstrual cramps, postoperative pain and tennis elbow.

In 1998, the National Institutes of Health asked a panel of experts from major U.S. medical centers to evaluate acupuncture. Their report, published in the Journal of the American Medical Association, concluded: "More than 1 million Americans receive acupuncture each year. The data in support of acupuncture are as strong as those for many accepted Western medical therapies. There is sufficient evidence of acupuncture's value to expand its use into conventional medicine."

The United Nations World Health Organization agrees, endorsing acupuncture for more than 40 conditions.

The NIH panel was also impressed with acupuncture's safety: "The occurrence of adverse events in acupuncture has been documented to be extremely low," its report said, "lower than that of many drugs or other accepted medical procedures."

Whatever the experts decide, however, acupuncture has found a true believer in Valerie Wilkerson. So much so that she now devotes her life to getting out the message to addicts in her old crack-ridden neighborhood while working as a community liaison for Lincoln's substance abuse treatment program.

"I encourage users to come in for treatment. I tell them I tried other programs, but finally got off drugs at Lincoln. Acupuncture had a lot to do with it. It definitely helped me, and I've seen it help many others."