A year ago, Soviet journalist Oleg Bitov made a dramatic appearance at a press conference here and said that he had been kidnaped, drugged, and coerced by British secret agents into staging a phony "defection" to the West.

In both form and content, it was similar to the news conference that had been held yesterday at the Soviet Embassy's residential compound in Washington, where Vitaly Yurchenko, a senior official of the KGB, the Soviet secret police, issued equally sensational charges against the Central Intelligence Agency.

There are also elements of similar patterns emerging in the return of some soldiers who had defected in Afghanistan and some returning emigres.

Today, the Soviet news agency Tass accused the United States of an "act of terrorism," charging that it had abducted Yurchenko from Italy. "It was a flagrant violation of the elementary human rights of the Soviet diplomat," Tass said.

Soviet television showed scenes tonight from Yurchenko's news conference yesterday in Washington. There has been no indication whether Yurchenko will hold another meeting with reporters when he returns here.

Both Yurchenko and Bitov claim to have been kidnaped in Italy, to have been kept on drugs and isolated and to have slipped away from the intense surveillance of foreign agents.

On Sept. 17, 1984, Bitov, 52, an editor at the weekly Literary Gazette, said the British secret service had conducted a series of crude and brutal "cloak and dagger" operations that began when he had gone to Venice the year before to cover the film festival.

Bitov's return was presented as a major propaganda coup by the Soviets, both at home and abroad. The press conference was held at the Foreign Ministry press center, and his charges were outlined in a nine-page statement, distributed in four languages. A more graphic account was printed in a three-part series in the Literary Gazette, the official publication of the Union of Soviet Writers.

Since then, Bitov, whose brother Andrei is also a well-known writer, has continued his association with the newspaper, publishing an article last March alleging a CIA connection to a plot to assassinate Pope John Paul II.

By the wide publicity it received, Bitov's return recouped much of the damage to the Soviet public image caused by his original request for asylum. While his story was denied vigorously by Britain and met with skepticism elsewhere in the West, the fact is that he returned to Moscow -- and has stayed.

The message implicit in his treatment upon reappearing in Moscow may be that defectors, or emigres, can come home again -- provided that they make a public statement blasting the West.

In Bitov's case as in others, it is not known how voluntary the return was. But publicly, at least, there was no retribution for any betrayal, which had been explained away by the story of capture and coercion.

A similar pattern has emerged with the return of Soviet soldiers who had deserted or been captured by opposition forces in Afghanistan.

One of them, Nikolai Ryzhkov, came back from New York last January and told Tass that he had been seduced in the West by "sleazy propaganda and dubious love." The young soldier said he had been forced to make anti-Soviet statements.

Two other Soviet soldiers who had gone to Britain and returned here in November 1984 also claimed that they had been duped into slandering the Soviet Union.

The fact that these cases were publicized without mention of punishment for acts considered crimes by most armies suggested that the Soviet Union did not want to discourage others from returning, or being persuaded to return.

Similar messages appear to have been beamed at emigres who have gone West. Of those, the most celebrated case was Svetlana Alliluyeva, daughter of Joseph Stalin, who came back early this year. In a press conference, she said she had not enjoyed a day of freedom during her years in the West. She now lives with her teen-aged daughter near Tbilisi, capital of Soviet Georgia, where her father was born.