obsessive

nouns

a person who has obsessions
obsessive
is a type of (narrower)
a person suffering from neurosis
mental case, neurotic, psychoneurotic

adjectives

characterized by or constituting an obsession
"the obsessional character of his response"; "obsessive gambling"
obsessional, obsessive
is derived from
obsessivity
is derived from
obsessiveness
is derived from
obsess