Mirrored-self misidentification

Mirrored-self misidentification is the delusional belief that one's reflection in the mirror is another person – typically a younger or second version of one's self, a stranger, or a relative. This delusion occurs most frequently in patients with dementia and an affected patient maintains the ability to recognize others' reflections in the mirror. It is caused by right hemisphere cranial dysfunction that results from traumatic brain injury, stroke, or general neurological illness. It is an example of a monothematic delusion, a condition in which all abnormal beliefs have one common theme, as opposed to a polythematic delusion, in which a variety of unrelated delusional beliefs exist. This delusion is also classified as one of the delusional misidentification syndromes (DMS). A patient with a DMS condition consistently misidentifies places, objects, persons, or events. DMS patients are not aware of their psychological condition, are resistant to correction and their conditions are associated with brain disease – particularly right hemisphere brain damage and dysfunction.