Autopsychosis

Autopsychosis is a type of disordered thinking in which a person has delusional thoughts about themselves. The prefix 'auto' refers to the self - so this could be said to be a psychosis about oneself. So a person who was suffering from an autopsychosis would have delusional ideas about themselves in some manner. For example, an individual who truly believed they were an alien sent down from space to take over the world would be suffering from autopsychosis.