Fregoli Delusion is a psychological condition where a person believes that different people are actually a single individual who changes appearance or disguises themselves. This delusion often leads to the belief that this person is following or persecuting them, causing significant distress. The condition is named after the Italian actor Leopoldo Fregoli, known for his quick changes in character and appearance. It is considered a type of paranoid delusion and is often associated with other mental health disorders, such as schizophrenia or bipolar disorder. Treatment typically involves therapy and medication to address underlying issues.