Sydenham

Schizophrenia, as one form of insanity, had occasionally been described in the 17th century, including by Thomas Sydenham, who differentiated insanity from ‘‘phrenitis’’ by the absence of a fever.

Fuller Torrey, E, Yolken, R (2001),
The Schizophrenia–Rheumatoid Arthritis Connection:
Infectious, Immune, or Both?