Henry Andrews Cotton was an American psychiatrist and the medical director of the New Jersey State Hospital at Trenton, in Trenton, New Jersey. During his tenure from 1907 to 1930, Cotton and his staff employed experimental surgery and Bacteriology techniques on patients, which included the routine removal of some or all of patients' teeth as well as tonsils, spleens, colons, ovaries, and other organs. These pseudoscientific practices persisted even after statistical reviews disproved Cotton's claims of high cure rates and revealed high mortality rates as a result of these procedures.

Adolf Meyer was a Swiss-born psychiatrist who rose to prominence as the first psychiatrist-in-chief of the Johns Hopkins Hospital (1910–1941). He was president of the American Psychiatric Association in 1927–28 and was one of the most influential figures in psychiatry in the first half of the twentieth century. His focus on collecting detailed case histories on patients was one of the most prominent of his contributions. He oversaw the building and development of the Henry Phipps Psychiatric Clinic at Johns Hopkins Hospital, opened in April 1913, making sure it was suitable for scientific research, training and treatment. Meyer's work at the Phipps Clinic is possibly the most significant aspect of his career.