I’ve come across this word a few times recently, while reading “The Case of Charles Dexter Ward, by H.P Lovecraft.
Coincidentally, this has happened shortly after the beginning of a TV series entitled The Alienist, based on a novel of the same name. Chalk that up to the Baader-Meinhof phenomenon, I suppose.
The term is a 19th-century one to refer to someone who treats mental illness (either a psychiatrist or a psychologist). It comes from the French aliéniste, which comes from an older sense of the word alienation, meaning insanity or loss of mental faculty.
It’s interesting to trace the origins of the word alienation and its related forms. It comes from the Latin verb alienare, which could mean to make another’s, part with, estrange, or set at variance.
In all these meanings we can see the general sense of separation and isolation. It’s no surprise that we use words like alienation the way we do now in English. Or even the word alien. It can mean either someone from another country, or from another planet. Of course if you call someone from another country an alien, you’re very likely to be using the term in a negative sense, because of the sense of difference and separateness contained within the word.
Of course, we no longer use the term alienist, and I think that shows how things have improved in terms of how we talk about mental health. We saw before how psychologist and psychiatrist are derived from the Greek word for soul or spirit, which is much more positive than the concept of alienation. Things aren’t perfect, but at least we’ve made some progress.