BEHIND the EYES of MADNESS is an exceptional look into the world of the insane, and reading it through without thought of the role-playing aspect once could easily accept that it was written by an author who was off his proverbial rocker.
To begin with it seems as if you are reading someone's sexual fantasies and what their belief of each sexual and violent act and illness is. Mixing fact with fiction, reality with fantasy, the author opens a wide world that could easily be explained as insane if it wasn't for the fact that more than half of what he writes can be read almost daily in the national newspapers.
Until we get to the section on Colin we are not sure of the authors intentions - are they to scare us, make us believe or are they simply experiences that a role-playing character might suffer or enjoy? When the Colins make his/their appearance there is more of an element of science fiction and fantasy, yet somehow there is also a nagging doubt that all is unreal and that perhaps it is an insight into the world of an insane killer may really be.
Some of this volume - the new skills, abilities, advantages, etc are easily slipped into the rpg but much of the information reads as if it was from a documentary or factual reference volume and as such is hard to see how useful it would be in a role-playing adventure.
As for a book and game where insanity is the main topic it makes Call of Cthulhu look fluffy.