Dr. Whitehorn was born in Nebraska, attended local schools, and worked his way through Doane College, earning an A.B. (1916). He taught science for a year and published his first article about the electron nature of matter in Scientific American. He entered Harvard Medical School and received his M.D. in 1921. He interned at the McLean Hospital near Boston, where he was Director of the Laboratory (1935–38), a Research Fellow, and later Associate in Psychiatry at Massachusetts General Hospital.
In 1938, Dr. Whitehorn became Professor of Psychiatry at Washington University and Psychiatrist-in-Chief at Barnes Hospital and associated hospitals. In 1941, he was recruited by Johns Hopkins and appointed the Henry Phipps Professor of Psychiatry and Psychiatrist-in-Chief. He held both positions until his retirement in 1960 and then served on the Maryland State Board of Health and Hygiene, becoming chairman in 1967.
Dr. Whitehorn’s interest moved from the biological to the psychotherapeutics of clinical care, and he published many papers. Dr. Whitehorn received many accolades for his achievements from many associations, including awards from the American Psychopathological Association (1953), the Association for the Advancement of Psychotherapy (1961), the Bowis Medal from the American College of Psychiatrists (1967), and the Salmon Medal from the New York Academy of Medicine (1971).
He was President of the American Board of Psychiatry and Neurology (1946–49). Dr. Whitehorn served as President of the American Psychiatric Association (1950–51).