In the course of his career, Bowman conducted pioneering work on the psychiatric effects of alcohol, drugs, and sexuality. He also conducted research on schizophrenia and the use of
insulin shock therapy. He testified at the trials of
Nathan F. Leopold and
Richard Loeb for the murder of Robert Franks in 1924 as well as in many other celebrated cases. During his career, Bowman was the chief medical officer at the
Boston Psychopathic Hospital; an assistant professor of psychiatry at
Harvard Medical School (1921–1936); the chief of psychiatry at
Bellevue Hospital (1936–1941); a professor of psychiatry at
New York University Medical College (1936–1941); the first chairman and director of the
Langley Porter Psychiatric Institute (1941–1956); and a professor at the University of California, Berkeley. He was also the head of the
Laguna Honda Psychiatric Hospital in San Francisco (1941–1967) With
E. Morton Jellinek, he co-wrote an influential 1941 article, "Alcohol Addiction and Its Treatment," synthesizing prior typologies of alcoholism and classifying alcoholics into four types, which was the basis of Jellinek's later five-stage typology. He also researched and wrote on
marijuana.
Schizophrenia Karl Bowman read his article "The Modern Treatment of Schizophrenia" at the
New York Academy of Medicine in New York on February 17, 1939. During his reading, Bowman stated, "over one half of the population of State Hospitals" consisted of patients diagnosed with
schizophrenia. He claimed that this psychological disorder did not shorten the lifespan of the patient, but resulted in the deterioration of the patient's brain. In his article, Bowman addresses many different methods that were used throughout history to help treat schizophrenia. For example, fever therapy consisted of inducing a fever in the patient using various methods, such as the malaria virus, but did not produce effective results in the treatment of schizophrenia. Sleep therapy was carried out using sleep-inducing substances such as
marijuana,
opium, and somnifen. Bowman also addresses stimulus therapy; this method had only temporary effects. Bowman recommended the insulin method as effective, with longer-lasting effects and more indications of long-term improvement. Bowman was optimistic about schizophrenia patients whose conditions had improved or had been cured and also about future treatment methods for schizophrenia patients.
Homosexuality During the 1950s and 1960s, Bowman collaborated in a number of studies on homosexuality and wrote a report on it for the State of California. In 1953, in "The Problem of Homosexuality," co-authored with Bernice Engle, he argued for multiple causes, including genetics, but proposed that castration be studied as a cure. However, in 1961 he appeared in the television documentary
The Rejected presenting the viewpoint that homosexuality is not a mental illness and should be legalized.
Legacy in the Philippines In the 1920's, Bowman supervised Dr. Jose Fernandez, a Filipino physician and future clinical director of the National Psychopathic Hospital, in the Philippines. After the war, Dr. Bowman responded to appeals from his former trainee and sent "a small check and some books" while at the same time encouraging his colleagues to do the same. ==Selected works==