CHICAGO, AUG. 28 -- The American Medical Association led an effort to destroy the chiropractic profession by depriving its practitioners of association with medical doctors and calling them "unscientific cultists" or worse, a federal judge has ruled.

U.S. District Court Judge Susan Getzendanner described the conspiracy as "systematic, long-term wrongdoing and the long-term intent to destroy a licensed profession" in ruling late Thursday on a 1976 antitrust lawsuit.

Getzendanner's said the nation's largest physicians' group spearheaded a medical doctors' boycott designed "to contain and eliminate the chiropractic profession."

A top AMA official disputed the judge's decision. "We don't think there was ever a boycott or a conspiracy," said Dr. Alan Nelson, chairman of the AMA board of trustees, in a telephone interview from Salt Lake City.

Chiropractic is a method of treatment based on the theory that disease is caused by interference with nerve function, which practioners try to correct by manipulating the spine and other joints.

In addition to "labeling all chiropractors unscientific cultists and depriving chiropractors of association with medical physicians, injury to reputation was assured by the AMA's name-calling practice," Getzendanner said.

The lawsuit, filed by four chiropractors, accused the Chicago-based AMA, four AMA officials and 10 other medical groups of conspiring to prevent chiropractors from practicing in the United States. Getzendanner held that the American College of Surgeons and the American College of Radiology had participated in the conspiracy with the AMA.

Thomas Greeson, attorney for the radiologists group, which is based in Reston, said he was studying the ruling and would have no immediate comment. The spokeswoman for the Chicago-based surgeons' group was unavailable for comment.

The judge scheduled a Sept. 4 meeting of the parties involved in the lawsuit to determine a remedy.

The lawsuit sought no monetary damages but challenged the defendants' refusal to acknowledge chiropractors' professional abilities.

Kirk Johnson, the AMA's general counsel, questioned the ruling.

"To me, the decision is wrong because we have had a policy, which has been very clear for a long time, that it is not unethical to associate with a chiropractor if you believe that it is in the patient's best interest," he said today.

"I am absolutely convinced the AMA will appeal," the plaintiffs' attorney, George McAndrews, said.

"The four chiropractors have weathered 11 years of hell to call the AMA and its coconspirators into account," McAndrews said.

Getzendanner said the function of the AMA's Committee on Quackery formed in 1962 was to destroy the chiropractic profession.