mental institution vs mental hospital

mental institution and mental hospital both are nouns.

Word	Noun	Adjective	Verb	Adverb
mental institution	Yes	No	No	No
mental hospital	Yes	No	No	No

As nouns, mental institution and mental hospital are synonyms defined as:

mental institution and mental hospital: a hospital for mentally incompetent or unbalanced person

Other synonyms of mental institution include asylum, insane asylum, institution, mental home, psychiatric hospital.

mental institution (noun)	mental hospital (noun)
a hospital for mentally incompetent or unbalanced person	a hospital for mentally incompetent or unbalanced person