I have gone out on a limb here, with a completely radical, clean, simplistic (you don't often get those words in a sentence together!) design, in a contest filled with dark, dark images so far!.
The rationale here is, from the CH description/Brief, it sounds like despite the cacophony of "strange" going on in the main characters mind, he is still managing to get stuff done. Calm and coordinated on the outside (white), even though feathers are flying in his internal psyche.
The peace of the cover, and the turmoil/tension inside the book creates an allegory of the equilibrium in the main character.
Just a thought, processed into this cover.