psychoactive drug vs psychoactive substance

psychoactive drug and psychoactive substance both are nouns.

Word	Noun	Adjective	Verb	Adverb
psychoactive drug	Yes	No	No	No
psychoactive substance	Yes	No	No	No

As nouns, psychoactive drug and psychoactive substance are synonyms defined as:

psychoactive drug and psychoactive substance: a drug that can produce mood changes and distorted perceptions

Other synonyms of psychoactive drug include consciousness-altering drug, mind-altering drug.

psychoactive drug (noun)	psychoactive substance (noun)
a drug that can produce mood changes and distorted perceptions	a drug that can produce mood changes and distorted perceptions