catathymia vs mental condition

catathymia and mental condition both are nouns.

Word	Noun	Adjective	Verb	Adverb
catathymia	Yes	No	No	No
mental condition	Yes	No	No	No

As nouns, mental condition is a hypernym of catathymia; that is, mental condition is a word with a broader meaning than catathymia:

catathymia: A state in which mental processes are under the control of the emotions.
mental condition: (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 catathymia include mental state, psychological condition, psychological state.

catathymia (noun)	mental condition (noun)
A state in which mental processes are under the control of the emotions.	(psychology) a mental condition in which the qualities of a state are relatively constant even though the state itself may be dynamic