Dr Samuel B. Guze died on 19 July 2000 at Barnes-Jewish hospital of complications from a bone marrow disorder. He was 76 years old.

Dr Guze was among the first to use studies of twins as a means of identifying the role of heredity in psychiatric illness. His work spawned great interest in the genetics of psychiatric disorders.

“Dr Guze has been one of the people most responsible for the fact that in the second half of the 20th century, psychiatry has moved into the mainstream of medical science,” said Dr Richard W. Hudgens, Professor of Psychiatry at the School of Medicine: “He has been the most articulate and consistent advocate of clinical psychiatry as a scientific endeavour.”

Dr Guze served as Vice Chancellor and President of the Washington University Medical Center from 1971 - 1989 - a period of its rapid expansion in medical care and medical research. He was head of the department of psychiatry 1975- 1989 and again 1993- 1997.

Dr Guze was also Psychiatrist-in-Chief at Barnes-Jewish and St Louis Children's Hospitals. He trained hundreds of psychiatrists. In 1980 Guze and his colleagues helped to create the American Psychiatric Association Diagnostic and Statistical Manual of Mental Disorders, a manual that has become the standard reference text for diagnosing mental illness. He published more than 200 scientific papers and several books. He was also the recipient of many awards for his contributions to the advancement of psychiatry, including his most recent in January - the Dr Thomas William Salmon Medal from New York Academy of Medicine.

Born in New York, Dr Guze graduated from a high school in New York at the age of 15 and attended the City College of New York. He earned his medical degree from Washington University. He started his career as an internist, but switched to psychiatry.

In 1998 Guze and his wife of 54 years, Joy, established the Samuel B. Guze Professorship in Psychiatry at Washington University.

He was the Spencer T. Olin Professor of Psychiatry at Washington University at the time of his death. He is survived by his wife, son, daughter and five grandchildren.