A dissident psychiatrist has appeared within the Soviet mental gulag.

In a striking challenge to his country's medical and political leadership, a highly placed Moscow psychiatrist has attacked standard Soviet psychiatric theories, which lend themselves to labeling dissidents "schizophrenic" and locking them up.

The attack appears in an article in the Archives of General Psychiatry, published in Chicago by the American Medical Association.

It marks the first time in recent years that a dissenting Russian psychiatrist has challenged his country's dominant psychiatric methods.

In his article, Dr. Etely P. Kazanetz of Moscow's Serbsky Institute of Forensic Psychiatry questions standard Russian psychiatric methodology, which most psychiatric apply to all patients, but which can also be used to incarcerate dissidents.

For example, the standard definition of schizophrenia -- though Kazanetz does not say this -- is so broad it can include "reformism," meaning the passionate urge to change society through clashes with authorities.

Kazanetz takes issue with the diagnostic methods created by Russia's most influential psychiatrist, Dr. Andrei V. Snezhnevsky. As chief of the Institute of Psychiatry of the U.S.S.R. Academy of Medical Sciences, he has made many of the diagnoses that have put dissidents in "special hospitals" for the criminally mentally ill.

Kazanetz does not refer in his article to dissidents. Based on an analysis of case histories of more than 300 patients, he merely speaks of many "over-diagnoses," "incorrect diagnoses," "the necessity for revising many long-standing diagnoses" and the "overextended" criteria of "the Snezhnevsky school."

But Kazanetz does warn that over-diagnosis and long retention of patients on psychiatric dispensary lists "constitutes a real threat to their individual rights."

Instead of maintaining that most misdiagnosed patients were really healthy -- as Western psychiatrists believe most hospitalized dissidents were -- he maintains they actually had treatable "exogenous psychoses," or brief, temporary illnesses, not schizophrenia.

Treatment for these "exogenous" illnesses -- illnesses caused by outside stresses rather than internal makeup -- need be only limited, Kazanetz wrote, with no need in general for long followup and "rehabilitation," including repeated visits to the patient's home. Such visits are another common Soviet practice.

In an interview, a leading American authority on Soviet psychiatry -- Dr. Walter Reich of Yale University and the National Institute of Mental Health -- said Kazanetz' careful, limited language must be read in "the Sovret context."

"What is news," he said, is that "there is dissent" in Russian psychiatry, and Kazanetz' article is "a remarkable act of courage."

"When I read the article," Reich explained, "I was amazed," because from "within the very bastions of Soviet psychiatry," Kazanetz challenges the system's dominant views.

Kazanetz has long been regarded by his colleagues as a "loner" and "something of a troublemaker," Reich added, and some Soviet psychiatrists have even called him "schizophrenic" to deride his views.

Still, that he was willing to mail an article to an American journal could mean more Soviet psychiatrists are starting to question Snezhnevsky's views, Reich said.

But there is no serious crack yet in the ranks of the Russian doctors of the mind. In the judgement of the Sixth World Congress of Psychiatry, they have habitually placed dissidents in hospitals, where they are often heavily drugged.

Some Western psychiatrists think at least 200 dissidents have been so incarcerated in recent years. Some think the number is far larger. Reich says, "We just don't know the number."

Yet, Reich also maintains, it is an iversimplification to think most Russian psychiatrists confine dissidents on order, though some do.

"The reality is far more complicated," Reich said. "The motivations are more complex, with a tremendous amount of self-deceit.

"What you have, first, is the set of established theories, a system, which does over-diagnose many persons, the vast majority of whom are not dissidents.

"Then you, a psychiatrist, are given a dissident patient to diagnose. You know the KGB is involved. Now, if you see strange symptoms -- and sissent is very strange in the Soviet Union -- and those symptoms fall within the established, overly broad definitions of schizophrenia, it's a relief to be able to come up with a diagnosis.

"And you can always tell yourself, 'At least this person won't go to a labor camp.'"