Dr. Joseph S. Costa, 49, a psychiatrist in private practice in Arlington since 1968, died Monday of a heart attack while on a trip to Rio de Janeiro.

He was instrumental in 1973 and 1974 in establishing a psychiatric department at Arlington Hospital and served as head of the 22-bed facility from 1975 until last December.

Dr. Costa was on the Arlington Hospital staff at the time of his death. He also has been associated with Fairfax Hospital since 1961.

From 1958 to 1961, he had been a medical officer and psychiatrist at D.C. General Hospital, and from 1958 to 1963 a clinical professor at Georgetown University Hospital.

In 1961, the Junior Chamber of Commerce in Washington honored him as the "outstanding young man in the District government" for his work in developing and coordinating a rehabilitation program for narcotics addicts at D.C. General Hospital.

Born in Spring Valley, Ill., Dr. Costa served in Europe in the Army Medical Corps in World War II, participating in the Battle of the Bulge.

He graduated from the University of Notre Dame in 1949 and from Georgetown University School of Medicine in 1954. He served his internship at the University of Chicago Medical Center and his residency in psychiatry at Georgetown University Hospital.

Dr. Costa was a charter member of the Northern Virginia chapter of the Washington Psychiatric Society and belonged to the American Medical Association, the Medical Society of Virginia and the Arlington County Medical Society. He was a fellow of the American Psychiatric Association.

He is survived by his wife, Joan Reback Costa, and a son, Joseph Samuel Jr., of the home in Falls Church; his mother, Mrs. Eugene Mahan, of Spring Valley, and a half-sister, Mo- [TEXT OMITTED FROM SOURCE]