Overvalued idea Overvalued ideas are exaggerated beliefs that a person sustains beyond reason but are not as unbelievable and are not as persistently held as delusions . Preoccupation with a spouse's possible infidelity can be an overvalued idea if no evidence exists to arouse suspicion. Body dysmorphic disorder 's obsessive preoccupation that some aspect of one's appearance is severely flawed is another example of an overvalued idea. An overvalued idea is something between an obsession and a delusion. A delusion is a firm belief held on inadequate grounds that can not be explained by the person's religious, cultural or educational background. It is unshakeable and can not be modified with arguments or logic. For example, someone might say that their bowels are rotten, so they should not be eating, and nothing would change their belief. Overvalued Idea compared with delusion and obsession An overvalued idea is like a delusion, except that it is somewhat logical and in