(The New York Times News Service) - Acupuncture is widely used as a treatment for cocaine addiction. But the results of a large clinical trial suggest that when used alone without other treatments the therapy is not effective in reducing cocaine dependency, researchers reported Wednesday.

Needles inserted into four acupuncture zones in the ear that are commonly used in treating addiction did no more to curtail cocaine use than relaxation exercises or a sham procedure in which needles were inserted into the rim of the ear. The study participants received the acupuncture or the other treatments five times a week for eight weeks.

Dr. Arthur Margolin, a research scientist at Yale's School of Medicine and the main author of the study, said that based on the findings, "the recommendation would be that acupuncture not be used by itself as a treatment for addiction, or in a setting where there is only minimal counseling or therapy."

But Margolin added, "I don't think this trial shows that acupuncture is ineffective across the board."

Some practitioners who use acupuncture to treat cocaine addiction did not dispute the study's findings but said the technique was rarely used alone and was usually combined with other treatments. The way that acupuncture might work to treat addiction remains unclear.

A report on the study appeared Wednesday in The Journal of the American Medical Association.

Earlier studies of acupuncture as a treatment for cocaine dependency, one of the most difficult forms of drug addiction to combat, have emerged with mixed results. A smaller trial at Yale last year found the therapy to be effective in helping some people reduce their reliance on the drug.

Experts on addiction said the new trial - by Margolin, Dr. Herbert D. Kleber, of Columbia University's National Center on Addiction and Substance Abuse, and more than a dozen collaborators at six community-based drug dependency clinics around the country - was the largest to test acupuncture's effectiveness for drug addiction and among the largest to examine the method's usefulness in any medical condition.

Of the 620 adults who initially enrolled in the trial, 208 of whom regularly used heroin as well as cocaine, almost half dropped out before the study's completion, as is common in studies of addiction treatment.

Those who remained showed a significant reduction in cocaine use, as measured by urine samples. But the extent of the reduction was the same no matter which treatment the subjects received.

And while some experts have argued that acupuncture helps people with drug problems stay in treatment, the subjects who received acupuncture were no more likely to finish the trial or to attend the counseling sessions that were offered to participants.

Margolin said the findings were unexpected in light of the earlier, positive results from the smaller Yale trial.

In their report, Margolin and his colleagues suggest that the difference may be explained by the fact that the subjects in the smaller Yale study received more intensive individual counseling and weekly group therapy in addition to acupuncture. And unlike the Yale subjects, the participants in the national trial were paid $2 per session and an additional $10 at the end of each week for their participation. Those who remained in the study until the end were the most severely addicted and the least motivated to conquer their dependency.

Dr. Michael Smith, the director of the Lincoln Recovery Center, part of Lincoln Medical, where the acupuncture procedure employed in the trial was developed, said the technique was used by as many as 1,500 drug treatment clinics worldwide. But Smith, who served on an advisory committee for the trial, added that acupuncture was almost always combined with other treatments and that he was not surprised by the findings.

"We never claimed nor does the study claim that acupuncture is a stand-alone treatment," Smith said.

Copyright 2002 The New York Times News Service. All rights reserved.