Mirrored self-misidentification

Mirrored self-misidentification is the delusional belief that one's reflection in a mirror is some other person (often believed to be someone who is following them around). Often people who suffer from this delusion are not delusional about anything else. It is considered to be a monothematic delusion and sometimes also labeled as a delusional misidentification syndrome. This disorder is often found within the context of dementia and can also be the caused by organic disfunction as a result of traumatic brain injury, stroke, or neurological illness.

Causes
Like other monothematic delusions, mirrored self-misidentification is currently thought to be initially caused by a neurological defect, typically in the right hemisphere, which affects ones experience. Current research points toward two potential disfunctions that may lead to this disorder:
 * Patients who have impaired face perception and thus can no longer recognize themselves (similar to Capgras delusion)
 * Patients who have lost the ability to interact appropriately with mirrors.