psychoactive substance

NOUN
22 LETTERS · STARTS WITH P

psychoactive substance is a valid 22-letter word worth 40 points in Scrabble and 46 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
P3S1Y4C3H4O1A1C3T1I1V4E1S1U1B3S1T1A1N1C3E1
3 + 1 + 4 + 3 + 4 + 1 + 1 + 3 + 1 + 1 + 4 + 1 + 0 + 1 + 1 + 3 + 1 + 1 + 1 + 1 + 3 + 1 =40 PTS
DOUBLE WORD → 80TRIPLE WORD → 120
MEANING

What does psychoactive substance mean?