Hugh Mullan, 91, a Washington psychiatrist who was an early practitioner of group therapy and served as president of the American Group Psychotherapy Association, died of congestive heart failure March 22 at the Washington Home. He lived in the District.

Dr. Mullen trained as a physician and as a traditional Freudian psychiatrist prior to World War II and began practicing group therapy in New York in the early 1950s. Family members said he courted controversy in his acceptance of group practice methods, therapists who were not physicians and the premise that the therapist as well as the patient was altered during the therapeutic process.

In the early 1970s, he ran the Area C Mental Health Services Program, based at D.C. General Hospital. From 1973 until he retired in 1986, he practiced privately in the Kalorama area of Washington. He also taught group therapy at Georgetown University, where he was a clinical professor of psychiatry, and at the Washington School of Psychiatry. In the late 1970s, he was an attending psychiatrist at St. Elizabeths Hospital.

Dr. Mullen wrote extensively about his principles of practice in psychiatric journals and wrote three books.

He was born on Staten Island, N.Y., while his father was serving in the Public Health Service there. Dr. Mullan graduated from the Severn School in Annapolis, the U.S. Naval Academy and the medical school of Cornell University.

He interned at the U.S. Marine Hospital on Staten Island, and then served as a medical officer in the Army Air Forces during World War II. He was posted to Europe in 1944 and 1945, and retired in the 1970s as a colonel in the Army Reserve.

After World War II, he trained in analytical psychiatry at the New York Psychiatric Institute and with Dr. Karen Horney under the auspices of the Association for the Advancement of Psychoanalysis. He was in private practice in New York before moving in the late 1960s to New Orleans.

He taught at Tulane University and was chief of psychiatry at the New Orleans Veterans Hospital.

Dr. Mullan was a member of the Cosmos Club, the American Psychiatric Association, the liaison group of the bioethics program at the National Institutes of Health and the Washington Metropolitan Bioethics Network.

Survivors include his wife of 61 years, Mariquita Paez MacManus of Washington; three children, Dr. Fitzhugh Mullan of Bethesda, Anthony Mullan of Washington and Dr. Mariquita Gabriela Mullan of Brookline, Mass.; and five grandchildren.