Unreliable narrator

Mentally unbalanced? Or not? Interesting questions to consider when writing a story from the point of view of an unreliable narrator. This could be anything from a serious genetic condition or a short-term reaction to trauma. No spoilers if you haven’t yet read The Wasp Factory by Iain Banks, only that the narrator, Frank, has issues. Banks also employs this device in Transition. In fact, the novel begins: Apparently, I am what is known as an Unreliable Narrator. In both these cases the narrator feels unstable but for many readers, including myself, the conclusion is drawn that their accounts are accurate in all things that matter. Thus, there can be something of a double twist in the use of this device. I recommend these books to everyone who likes something thought-provoking and out of the ordinary.