Samuel Guze

Samuel Barry Guze (October 18, 1923 – July 19, 2000) was an American psychiatrist, medical educator, and researcher. He was an influential psychiatrist and worked at the Washington University School of Medicine in St. Louis for most of his career.

Along with Eli Robins, George Winokur and others, Guze advanced psychiatry by establishing criteria for diagnosis. A short paper by Guze and Robins contained a discussion of validity from a medical perspective. and came up with five phases of research that demonstrated that a diagnostic concept represented a disease. These five phases were: clinical description, laboratory studies, delimitation from other disorders, follow-up studies and family studies. While previously two psychiatrists might interview the same patient and propose differing diagnoses, the Guze system lead to great leaps in diagnostic "reliability", that is, different physicians would agree more often on what the diagnosis really was. Following publication of what came to be known as the Feighner Criteria, in 1980 he helped compile Diagnostic and Statistical Manual for Mental Disorders (3rd edition). The diagnostic reliability is still an essential component to modern versions of the Manual.

He was also among the first psychiatrists to study twins as a way to investigate the role of heredity in mental illness and contributed to the knowledge of genetic vulnerability to alcoholism and schizophrenia.