psychological medicine vs psychiatry

psychological medicine and psychiatry both are nouns.

Word	Noun	Adjective	Verb	Adverb
psychological medicine	Yes	No	No	No
psychiatry	Yes	No	No	No

As nouns, psychological medicine and psychiatry are synonyms defined as:

psychological medicine and psychiatry: the branch of medicine dealing with the diagnosis and treatment of mental disorders

Other synonyms of psychological medicine include psychopathology.

psychological medicine (noun)	psychiatry (noun)
the branch of medicine dealing with the diagnosis and treatment of mental disorders	the branch of medicine dealing with the diagnosis and treatment of mental disorders