A drug best known for its use in treating hyperactive children eased mental and emotional impairment caused by the AIDS virus in a new study, a researcher reports.

The results emerged when Ritalin was given to 97 patients with acquired immune deficiency syndrome or AIDS-related complex, said Francisco Fernandez.Seventy-six percent showed moderate to marked improvement in such areas as energy, vigor and mood, while 67 percent showed gains in such areas as reaction time, information processing speed and long-term memory, he said.

Fernandez is chief of the psychiatric consultation service at St. Luke's Episcopal Hospital and assistant professor of psychiatry at the Baylor College of Medicine in Houston.

He addressed a symposium Sunday at the annual meeting of the American Psychiatric Association.