Yes, PSYCHOPATHY is a Scrabble word!

Letter values in Scrabble US: P 3, S 1, Y 4, C 3, H 4, O 1, P 3, A 1, T 1, H 4, Y 4.

Is it a valid word?

PSYCHOPATHY is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

any disease of the mind; the psychological state of someone who has emotional or behavioral problems serious enough to require psychiatric intervention

Also: mental illness, mental disease.