I would agree with the comments already posted to this site by the previous rater.
I first stumbled across this movie back in the '80s, when I was employed at a psychiatric hospital. Unfortunately, many of the barbs aimed at the psychiatric profession do hit home. I especially enjoyed the ending, where the psychiatrist would speak thru the door to the hospitalized Grodin. Trust me, its fairly accurate.
Of course, doors at most psych hospitals are not locked, nor are straightjackets used much these days, and any hospital MUST be licensed to have a "padded room".
But a wonderfully underrated film, and certainly one that is quite amusing.
Jeff