Reflections of the self: atypical misidentification and delusional syndromes in two patients with Alzheimer's disease.

Two patients with moderately severe AD, when asked directly, could identify their own images in a mirror, but also consistently misidentified their own reflections as that of another person. Both patients were paranoid and mildly depressed at times, but had no evidence of other concurrent psychotic symptoms. It appeared that mood substantially modified the nature of the symptom and the patients' reaction to it over time. These cases illustrate the ability of an organic symptom to be modified by a concurrent affective state, indicating the importance of the interaction between biological and psychological factors in the expression of such symptoms.