Although currently not often used, the term "alienist" is still used in psychiatric hospitals to describe those mental health professionals who evaluate defendants to determine their competency to stand trial.
New York Times; December 28, 1934, Friday; Two Alienists Report Alleged Budd Slayer Has Some Abnormalities. White Plains, New York; December 27, 1934. Two alienists reported today to Walter A. Ferris, District Attorney elect of Westchester County, that Albert Fish, 64 years old, held in the county jail for the murder of Grace Budd, is legally sane.
The ABC Murders by Agatha Christie; Dr. Thompson, "the famous alienist" is called to Scotland Yard to help Poirot and Inspector Japp find a murderer who mails Poirot cryptic letters before each murder. (1936)