Julius Wagner-Jauregg, original name Julius Wagner, Ritter (Knight) von Jauregg, (born March 7, 1857, Wels, Austria—died Sept. 27, 1940, Vienna), Austrian psychiatrist and neurologist whose treatment of syphilitic meningoencephalitis, or general paresis, by the artificial induction of malaria brought a previously incurable fatal disease under partial medical control. His discovery earned him the Nobel Prize for Physiology or Medicine in 1927.

While a member of the psychiatric staff (1883–89) at the University of Vienna, Wagner-Jauregg noted that persons suffering from certain nervous disorders showed a marked improvement after contracting febrile (characterized by fever) infections. In 1887 he suggested that such infections be deliberately induced as a method of treatment for the insane, especially recommending malaria because it could be controlled with quinine. As professor of psychiatry and neurology at the University of Graz, Austria (1889–93), he attempted to induce fevers in mental patients through the administration of tuberculin (an extract of the tubercle bacillus), but the program met with only limited success. In 1917, while occupying a similar post at the University of Vienna, where he also directed the university hospital for nervous and mental diseases (1893–1928), Wagner-Jauregg was able to produce malaria in paresis victims, with dramatically successful results.

Wagner-Jauregg, Julius Julius Wagner-Jauregg in an undated photograph. Encyclopædia Britannica, Inc.

Although malaria treatment of the disease was later supplanted largely by administration of antibiotics, his work led to the development of fever therapy and shock therapy for a number of mental disorders. He was also known as an authority on cretinism and other thyroid disorders.