alienism vs psychopathology

alienism and psychopathology both are nouns.

Word	Noun	Adjective	Verb	Adverb
alienism	Yes	No	No	No
psychopathology	Yes	No	No	No

As nouns, psychopathology is a hypernym of alienism; that is, psychopathology is a word with a broader meaning than alienism:

alienism: an obsolete term for the study and treatment of mental illness
psychopathology: the branch of medicine dealing with the diagnosis and treatment of mental disorders

Other hypernyms of alienism include psychiatry, psychological medicine.

alienism (noun)	psychopathology (noun)
the quality of being alien	the branch of medicine dealing with the diagnosis and treatment of mental disorders
an obsolete term for the study and treatment of mental illness	the branch of psychology concerned with abnormal behavior