CIA psychiatrists and chemical warfare experts treated then-President Nixon's osteopath for three months in 1972 after the physician showed signs of having been drugged on a presidentrial trip to the Soviet Union, knowledgeable sources said yesterday.

Dr. W. Kenneth Riland, a New York City physician who treated Nixon and other prominent political figures, was sent to the Central Intelligence Agency after he showed signs of severe disorientation and had unexplained crying fits following the Soviet trip, sources said.

Nixon apparently was not involved in any drugging incident and was never told of Riland's problems. But the sources said Dr. Walter Tkach, Nixon's personal physician, also showed milder symptoms of possible drugging. Tkach and Riland roomed together in the Kremlin during the trip.

The incident came to light yesterday during testimony by a former top CIA official before the Senate Human Resources subcommittee on health. The subcommittee has been investigating the CIA's long-running mind-control program called MK-ULTRA.

Sidney Gottlieb, who headed the CIA's technical services division and ran the MK-ULTRA project, told subcommittee chairman Edward M. Kennedy (D-Mass.) that, after Nixon visited an unidentified "potentially hostile country" in about 1971, his doctor reported experiencing "unusual feelings."

"There were inappropriate tears and crying," said Gottlieb. He refused to tell the subcommittee or reporters the names of either the physician or the country in which the suspected drugging took place.

Gottilieb said the doctor arrived at the CIA too late for specialists to determine by whom or even whether he had been drugged, or what types of drugs he might received.

Sources closely familiar with the incident said yesterday that Riland experienced the emotional problems within 72 hours after the Nixon party arrived in the Kremlin in 1972. Riland and former Secretary of State William Rogers flew together to London where the physician had difficulty recognizing old friends. He was referred to CIA specialists three weeks after the trip, according to the sources.

Both Riland and Tkach declined yesterday to comment formally on the incident.

During his testimony yesterday Gottlieb also said that there are at least 20 documented instances in which diplomatic or military attaches of the United States or other countries have been subjected to attacks with incapacitating drugs by a foreign country.

Gottlieb indicated that such attacks had occurred on at least one occasion against a U.S. courier. In that case, he said, a "potential enemy" slipped a pipe under the door of the courier's room and administered an odorless gas that knocked the man unconscious temporarily. The door was then opened and the courier's papers taken, said Gottlieb. He gave no other details.

The 59-year-old former CIA official, who destroyed most of the agency's MK-ULTRA records before his retirement in 1973, agreed to testify only after the subcommittee granted him limited immunity from prosecution. Because Gottlieb suffers from a serious heart condition, he gave his testimony to the subcommittee in a small antechamber and it was piped out to reporters through a public address system.

Gottlieb defended the controversial MK-ULTRA program and the CIA's drug experiments, saying that other countries' aggressive use of drugs in intelligence work and the lack of U.S. knowledge of drugs "posed a threat of the magnitude of national survival" in the Cold War atmosphere at the start of the program in the early 1950s.

He acknowledged that some of the MK-ULTRA projects bore little fruit for intelligence agents. In one, the CIA paid $375,000 for a new research wing on a Georgetown University hospital and never used the facility, he said.

On the other hand, Gottlieb said, the program enabled the CIA to understand better what other countries were doing in the drug field. On two occasions, he said, he and an assistant advised President Nixon on possible covert attacks that could be launched against him on trips abroad. He did not say which trips he was referring to.

Gottlieb acknowledged that the CIA had administered drugs to as many as 40 unwitting subjects in experiments at safe house the agency maintained in New York and San Francisco. In one case, which he said was "hazy" in his mind, one of the subjects of the experiments was hospitalized.

Gottlieb also knowledged that prostitutes were used in the operation of the safe houses, which are residences maintained by the CIA for various clandestine activities. He said the prostitutes were used because the CIA shared the program with the Bureau of Narcotics, and "in the method of operation of the Bureau of Narcotics prostitution is interwoven in the whole thing." But he denied allegations that pornographic films had been made through two-way mirrors in the houses.

In a statement he read to the committee, Gottlieb bitterly claimed the has been "victimized" by the CIA because the agency left only his name uncovered on thousands of pages of documents it has released on the MK-ULTRA project in the last two months.

A CIA spokesman acknowledged yesterday that Gottlieb's name had been made public despite an agency policy to black out other names in the documents. "It is so widely known anyway it wouldn't have made any difference if we did cover it up," the spokesman said.

In separate testimony before the subcommittee, CIA Director Stansfield Turner said three other CIA projects related to MK-ULTRA were primarily under the direction of the Defense Department. Subcommittee Chairman Kennedy challenged Turner's assertion with a letter from the Defense Department stating that all three projects were "planned, directed and controlled by the CIA."