Ok, I know what they do, I'm just not seeing where they add much to the game. It seems like something the players really can't control.
See, Corruption points are great. I use them constantly. To me, they're partially a measure of how well a character is holding onto their humanity. When they stop showing compassion for others or start to do blatantly sadistic or evil things, they earn corruption points. Pursuing forbidden knowledge, they gain corruption points as well. These things all require a decision on the part of the player and the player almost always has a certain amount of control in the matter. They can steer their character in a direction they want to go.
Insanity points don't seem to follow that. They seem to be arbitrarilly handed out to characters for just being in the wrong place at the wrong time. Something which, face it, Acolytes are supposed to be doing. The player doesn't seem to have much of a say in the matter or have any way of controlling or directing things. "Ooh! Scary monster just popped out of closet, here, have some insanity points."
Am I missing the point to them? Is there perhaps another way they should be used?