Donald Trump has disappeared into the smog of his own conspiracy theories. As he rages about poisonous fake news, he is spewing his own poisonous fake news.

Delusional disorder is classified as a psychotic disorder, a disorder where a person has trouble recognizing reality. A delusion is a false belief that is based on an incorrect interpretation of reality. 

A person with this illness holds a false belief firmly, despite clear evidence or proof to the contrary.