020 One Flew Over the Cuckoos Nest (1975)

Jack Nicholson's character thinks he can do some easy time if he convinces his warden that he is crazy, and he gets himself transferred to a mental hospital. he raises all kinds of ahvoc while he's there and hen he learns that he won't necessarily be released when his time is up, but he will remain committed until the doctors decide that he is cured. When he chafes at this and other injustices he is subjected to electro-shock therapy and finally labotomized. It's a truly horrific look at the state of mental health care in the 1970s.