mental disorder vs psychopathology

mental disorder and psychopathology both are nouns.

Word	Noun	Adjective	Verb	Adverb
mental disorder	Yes	No	No	No
psychopathology	Yes	No	No	No

mental disorder (noun)	psychopathology (noun)
(psychiatry) a psychological disorder of thought or emotion; a more neutral term than mental illness	the branch of medicine dealing with the diagnosis and treatment of mental disorders
	the branch of psychology concerned with abnormal behavior