5 Of The World’s Weirdest Mental Disorders

Published June 3, 2014
Updated September 12, 2018

Mental Disorders: Fregoli Delusion

Mental Disorders Mom

This is either your mother, or an alien replicant. Can’t be too careful. Image Source: Wikimedia Commons

If you enjoy meeting new people every day–and then accusing them of impersonating the people you love most and following you around–then Fregoli delusion is just the thing for you. People with this disorder are irrationally convinced (or are they?) that strangers have taken the place of their friends and family members and are wearing cunning disguises that only look like the faces they’ve known all their lives.

Researchers, in between shrugging and admitting that it’s really weird, speculate that the condition might have a basis in an organic brain disease, adding that “it is the dominant psychotic theme that determines the content of the syndrome” (according to the Australian and New Zealand Journal of Psychiatry), which is how science avoids using words like “crazy.”


Next up: What if your brain was telling you to eat strange things? No, really strange things…

Richard Stockton
Richard Stockton is a freelance science and technology writer from Sacramento, California.