Educational reference
About this symptom
A delusion is a belief held firmly despite clear evidence against it, and not shared by others in the person's culture or community.
Common themes include being watched, followed or persecuted; believing that ordinary events carry a special personal meaning; believing one has exceptional abilities or importance; or believing something is wrong with one's body.
Two points are commonly misunderstood. Delusions are not a failure of intelligence or reasoning ability — people with delusions may reason perfectly well in other areas. And they usually cannot be resolved by argument: presenting contrary evidence tends to entrench the belief rather than shift it, and can damage the relationship with the person trying to help.
Approaches that help more generally focus on the distress the belief causes rather than the belief's truth, and on maintaining a relationship in which the person feels able to talk.
Beliefs that others find unusual are not automatically delusions. Cultural, religious and community context matters, and assessment takes account of it.