Dr. Dexter M. Bullard Sr., 83, medical director of Chestnut Lodge sanitorium in Rockville for 38 years, who has taught courses in psychiatry at area universities and been a leader in professional organizations, died of cancer Tuesday at his home in Rockville.

Chestnut Lodge was founded by Dr. Bullard's father, Dr. Ernest L. Bullard, in 1910. The younger Dr. Bullard joined his father at the lodge in 1925 as an assistant physician and became medical director upon his father's death in 1931.

Over the years, Dr. Dexter Bullard director the lodge's evolution into a psychoanalytic hospital based on Freudian psychology. The hospital specializes in psychoanalytic psychotheraphy and is perhaps best known for its treatment of schizophrenic patients. He retired in 1969.

He was a past president of the Southern Psychiatric Association, the montgomery County Medical Society, and the Washington Psychoanalytic Society. He was a life fellow of both the American Psychiatric Association and American Psychoanalytic Association.

He taught clinical psychiatry at Georgetown University's medical school from 1933 to 1941, and was clinical professor emeritus of psychiatry at George Washington University. He was training and supervising analyst of the Washington Psychoanalytic Institute, and had been a consultant to the National Institute of Mental Health and the Walter Reed Army Institute of Research.

Dr. Bullard was born in Waukesha, Wis. After graduation from Sidwell Friends School in Washington, he earned an undergraduate degree at Yale University in 1920, and three years later graduated from the University of Pennsylvania's medical school. He received his psychiatric training at the Washington Psychoanalytic Institute and the Washington School of Psychiatry, where he later was a member of the faculty.

Dr. Bullard maintained that his approach to mental illness was shaped during his youth, when his father first directed a mental hospital in Wisconsin and then opened chestnut Lodge. In a speech in Toronto in 1968, he said that "psychotic patients were my baby-sitters, my escorts, my playmates. So I knew the psychotic as a person long before I knew what the implications of the word 'patient' were."

A profile of Dr. Bullard in a professional journal said that his guiding idea was "at once simple and profound, that while there are psychotic persons, there are no psychotics. The presence of a thinking disorder does not carry with it the loss of one's personhood [to include one's dignity, uniqueness and privileges as a human being]."

Dr. Bullard's survivors include his wife of 54 years, the former Anne W. Wilson, of Rockville; three sons, Dr. Dexter M. Jr., of Chevy Chase, Dr. James W., of Ashton, Md., and Anthony Ray Bullard of Rockville; a daughter, Rose Dyrud of Chicago, and 10 grandchildren.