A common way to convey that a character is either really strange or has either paranoid or schizophrenic tendencies (or both) is to make them an insomniac. Whether only during times of great stress or as a chronic disorder (obviously a case of Truth in Television) expect these characters to be cranky, moody, mistrusting and sometimes even violent. Expect lots of Eye Tropes. In fiction, four types can be observed: The webcomic No Rest for The Wicked can be found by following that link. Examples of The Insomniac include: