Psychiatric hospital
A psychiatric hospital or mental institution was a insane asylum. Funny farm was a slang term for the same.
Following his arrival to 1967 Earth from the 29th century, Captain Braxton became disillusioned with life among "post-industrial barbarians", and – despite his best efforts to explain his situation to various authorities, notably that of being a timeship captain from the future – he was eventually placed in a mental institution where they "filled [him] with primitive pharmaceuticals." (VOY: "Future's End")
In 2285, Leonard McCoy was to be sent to the Federation funny farm due to his mental issues, which had been induced by Spock's katra. (Star Trek III: The Search for Spock)
In 2364, Madeline told "Dixon Hill" that if Detective Dan Bell had seen him in his "threads", he'd send him to the funny farm. (TNG: "The Big Goodbye")