identity crisis vs mental state

identity crisis and mental state both are nouns.

Word	Noun	Adjective	Verb	Adverb
identity crisis	Yes	No	No	No
mental state	Yes	No	No	No

As nouns, mental state is a hypernym of identity crisis; that is, mental state is a word with a broader meaning than identity crisis:

identity crisis: distress and disorientation (especially in adolescence) resulting from conflicting pressures and uncertainty about one's self and one's role in society
mental state: (psychology) a mental condition in which the qualities of a state are relatively constant even though the state itself may be dynamic

Other hypernyms of identity crisis include mental condition, psychological condition, psychological state.

identity crisis (noun)	mental state (noun)
distress and disorientation (especially in adolescence) resulting from conflicting pressures and uncertainty about one's self and one's role in society	(psychology) a mental condition in which the qualities of a state are relatively constant even though the state itself may be dynamic