A delusion is a belief based on an inaccurate interpretation of reality, despite clear evidence to the contrary. A delusional disorder causes a person to have delusional thoughts for a prolonged ...

Delusional parasitosis (DP) is a rare psychiatric (mental) disorder. A person with this condition strongly believes that they’re infected with a parasite. However, this isn’t the case — they don’t ...

That’s how Merriam-Webster, which has been in the dictionary business for more than 190 years, defines who an anti-vaxxer is. The part about a person who opposes vaccination is fine, of course. But ...

When someone has persecutory delusions, they believe a person or group wants to hurt them. They firmly believe this is true, despite the lack of proof. It may occur with some mental health disorders.

A patient lies in a hospital bed in the neurological ward, his head wrapped in bandages. He’s just suffered a major trauma to the brain. The injury has wiped out the region that controls motion in his ...

Delusions of grandeur are a symptom of mental health conditions like bipolar disorder and schizophrenia. People with this ...