Dr. Robert Spitzer — a psychiatrist who played a leading role in establishing agreed-upon standards to describe mental disorders, a development that transformed the profession — has died. He was 83.

His wife, Columbia University Professor Janet Williams, says Spitzer died Friday in Seattle of heart problems.

Williams says Dr. Spitzer's work on several editions of the Diagnostic and Statistical Manual of Mental Disorders, or the D.S.M., "was a major breakthrough for the profession" because it defined all of the major disorders.

Gay-rights activists credit Dr. Spitzer with removing homosexuality from the list of disorders in the D.S.M. in 1973, the New York Times reported.

Dr. Allen Frances, a professor emeritus of psychiatry at Duke University and editor of a later edition of the manual, told the Times that Spitzer "was by far the most influential psychiatrist of his time."