mistreated vs abused

mistreated and abused both are adjectives.

Word	Noun	Adjective	Verb	Adverb
mistreated	No	Yes	No	No
abused	No	Yes	No	No

As adjectives, mistreated and abused are synonyms defined as:

Other synonyms of mistreated include ill-treated, maltreated.

mistreated (adjective)	abused (adjective)
subjected to cruel treatment	subjected to cruel treatment
	used improperly or excessively especially drugs