Dr. Brush was born in Erie County, N.Y., received his early education in Buffalo, and received his M.D. from the University of Buffalo in 1874. For a short time, he served at the Utica State Asylum under Dr. John P. Leroy as an assistant in pathology. In 1884, he moved to the Pennsylvania Hospital to be in charge of the men’s department, where he remained for seven years. In 1891, he became the first superintendent of Sheppard Asylum (later known as Sheppard and Enoch Pratt Hospital) in Baltimore, serving until his death.
While at Utica, Dr. Brush served as an associate editor for The American Journal of Insanity, which was owned by the hospital. In 1904, he succeeded Dr. Henry Hurd as Editor of the Journal and retained this post for 27 years. Dr. Brush was President of the American Medico-Psychological Association (1915–16).