mental hygiene vs psychotherapeutics

mental hygiene and psychotherapeutics both are nouns.

Word	Noun	Adjective	Verb	Adverb
mental hygiene	Yes	No	No	No
psychotherapeutics	Yes	No	No	No

As nouns, mental hygiene and psychotherapeutics are synonyms defined as:

mental hygiene and psychotherapeutics: the branch of psychiatry concerned with psychological methods

Other synonyms of mental hygiene include psychotherapy.

mental hygiene (noun)	psychotherapeutics (noun)
the branch of psychiatry concerned with psychological methods	the branch of psychiatry concerned with psychological methods