Insanity

Is it possible that insanity (or simply the tendency to come to believe unreasonable things) is actually an adaptation that allows people to adjust to new states of affairs that may be less desirable without becoming miserably unhappy? In the same way that the potential for genetic mutations is a crucial part of evolutionary processes, a tendency for brain pathology might be a way for the brain to adapt to a new set of surroundings that might not automatically be fit for a happy adaptation...