obsessional vs obsessive

obsessional is not a noun while obsessive is a noun.

Word	Noun	Adjective	Verb	Adverb
obsessional	No	Yes	No	No
obsessive	Yes	Yes	No	No

As adjectives, obsessional and obsessive are synonyms defined as:

obsessional and obsessive: characterized by or constituting an obsession

obsessional (noun)	obsessive (noun)
	a person who has obsessions

obsessional (adjective)	obsessive (adjective)
characterized by or constituting an obsession	characterized by or constituting an obsession