manic-depressive psychosis

NOUN
26 LETTERS · STARTS WITH M

manic-depressive psychosis is a valid 26-letter word worth 44 points in Scrabble and 49 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
M3A1N1I1C3-0D2E1P3R1E1S1S1I1V4E1P3S1Y4C3H4O1S1I1S1
3 + 1 + 1 + 1 + 3 + 0 + 2 + 1 + 3 + 1 + 1 + 1 + 1 + 1 + 4 + 1 + 0 + 3 + 1 + 4 + 3 + 4 + 1 + 1 + 1 + 1 =44 PTS
DOUBLE WORD → 88TRIPLE WORD → 132
MEANING

What does manic-depressive psychosis mean?