It's true that the A.P.A. is predominantly white and male. Of its current 38,200 members, only 865, or 2.3 percent, are African-American and 1,720, or 4.5 percent, are Hispanic. Some 12,000, or 31 percent, are women. And there is no doubt that psychiatry has been susceptible to some of the same biases harbored by the society at large, most notably toward women and homosexuals. Until well after World War II, instruction in now-discredited Freudian concepts like ''penis envy'' and ''castrating female'' was a routine part of psychiatric training. More egregious was the theory of the schizophrenic mother, whose bad parenting was supposedly to blame for her child's schizophrenia. Widely accepted well into the 1970's, the theory has been supplanted by explanations focusing on brain chemistry and biology.

Homosexuals fared little better. Until the early 1970's, the A.P.A. regarded homosexuality as a pathology. After heavy lobbying from gay rights activists, including a psychiatrist who was a member of the A.P.A. and who spoke at the 1972 annual meeting, his face concealed by a mask to preserve his anonymity, the board of trustees voted to remove homosexuality from the D.S.M.-IV. The membership followed suit in 1974. (One bemused observer labeled it ''the single greatest cure in the history of psychiatry.'')

Dr. Poussaint credits politics -- the women's movement and gay rights activists -- not better science, for overturning faulty psychiatric doctrine. His own politicking to change the association's opinion on racism has so far been less successful. In the mid-1960's, Dr. Poussaint joined other civil rights workers in Mississippi, where he helped desegregate the hospitals. The bigotry he witnessed among the region's white psychiatrists as well as a spate of racist killings convinced him to act.

Along with seven other black psychiatrists, Dr. Poussaint appealed to the organization to add racism to the D.S.M.-IV. Their request was turned down. ''Let's say that group of black psychiatrists had been in control of establishing what the diagnoses should be in the D.S.M.,'' Dr. Poussaint says now. ''In some way, racism would be in that book.''

Perhaps. Today, many of Dr. Poussaint's black colleagues say a D.S.M. label would actually be counterproductive. ''Racism is so deeply ingrained in our culture that to try to identify individuals who are racist is in some ways to trivialize the depth and breadth of the problem,'' says James Jones, a professor of social psychology at the University of Delaware and the director of the minority fellowships program at the American Psychological Association. Others believe that pathologizing racism would inadvertently give racists a legal defense for hate crimes.

On the whole, psychiatrists were probably more disposed to treat racism as a mental illness 50 years ago than today. In the 1950's, the profession even flirted with a quasi-medical definition of racism, although at the behest of the American Jewish Committee, not American blacks. In 1950, four scholars published an influential study titled ''The Authoritarian Personality.'' Three of the authors were Jewish. Two of them, including the philosopher Theodor Adorno, were refugees from Nazi Germany.