selective amnesia vs amnesia

selective amnesia and amnesia both are nouns.

Word	Noun	Adjective	Verb	Adverb
selective amnesia	Yes	No	No	No
amnesia	Yes	No	No	No

As nouns, amnesia is a hypernym of selective amnesia; that is, amnesia is a word with a broader meaning than selective amnesia:

selective amnesia: amnesia about particular events that is very convenient for the person who cannot remember
amnesia: partial or total loss of memory

Other hypernyms of selective amnesia include blackout, memory loss.

selective amnesia (noun)	amnesia (noun)
amnesia about particular events that is very convenient for the person who cannot remember	partial or total loss of memory