Letters to the Editor
Capgras Syndrome in the Modern Era: Self Misidentification on an ID Picture
Dear Editor: While living in a supervised apartment, Ms KL, aged 31 years, was hospitalized for a psychotic relapse in the course of undifferentiated schizophrenia. At admission, she presented with intense delusional (mostly persecutory) ideation, auditory hallucinations, severe anxiety, and mild depression. Her behaviour was grossly disorganized, and she required close supervision to tend to daily life activities. Her drug treatment was changed from risperidone 4 mg daily to olanzapine 30 mg daily, which elicited a partial symptom remission. Further improvement occurred with the addition of venlafaxin 225 mg daily, but she remained symptomatic and severely impaired, which led to the discussion and proposal of clozapine treatment, an option that, as of this report, she has refused.
During the course of the olanzapine and venlafaxin treatment, the patient presented with a new clinical relapse, including notably increased persecutory ideation and different components of Capgras syndrome. First, she discarded her health insurance (RAMQ) plastic card because she thought that its photograph was not her own and, more specifically, because she did not recognize her nose. Of note, the patient had held this card for years without particular concern. When rechallenged with the photograph, she still contended that it had been replaced or tampered with and did not recognize her face. Second, she also discarded various personal objects (such as her satchel, clothes, toilet items, and magazines) because she was convinced that they were not hers. She retrospectively admitted that she had already done so in the past; however, this behaviour was not active in the hospital before her relapse. Third, she became suspicious of her roommate, although with fluctuating conviction, because she thought that the latter had been replaced by someone charged with killing her.
While the second and third symptoms are fairly classic, this case adds the plastic ID card, a highly meaningful feature of contemporary life, to the long list of objects (in a broad sense) misidentified in Capgras syndrome: it stands at the limit of object (in a narrow sense), face, and self-recognition. Moreover, the quality of most ID photographs is poor (which was admittedly particularly pronounced in the present case), and the patient was therefore presented with a degraded picture, the recognition of which is notably difficult for patients with schizophrenia.
Because we had the opportunity to assess the occurrence of Capgras syndrome in an emerging state, we would also like to speculate on its clinical course in patients with schizophrenia. Visual, and especially facial, recognition difficulties are enduring features of schizophrenia, and some authors have suggested that these may be trait markers of the disease, as well as endophenotypes with potential use in genetic research (1,2). Conversely, Conklin and others have suggested that impaired recognition memory for faces is associated with increased positive symptoms in patients and increased schizotypal traits in their relatives (3). In the case discussed here, it can be argued that there was some stable level of visual recognition impairment; a fully developed Capgras syndrome, however, only appeared in association with a psychotic relapse. Within the framework of the “salience theory” of psychosis (4,5), this suggests that increased dopamine mesolimbic neurotransmission associated with psychotic relapse adds salience, novelty, and in this case, aversive features, to a familiar, albeit misidentified, visual stimulus that would otherwise have remained neutral in a remitted patient. Once present, however, Capgras syndrome shares the stability and refractoriness of the underlying cognitive deficit.
References
1. Loughland CM, Williams LM, Gordon E. Schizophrenia and affective disorder show different visual scanning behavior for faces: a trait- versus state-based distinction? Biol Psychiatry 2002;52:338–48.
2. Loughland CM, Williams LM, Harris AW. Visual scanpath dysfunction in first-degree relatives of schizophrenia probands: evidence for a vulnerability marker? Schizophr Res 2004;67:11–21.
3. Conklin HM, Calkins ME, Anderson CW, Dinzeo TJ, Iacono WG. Recognition memory for faces in schizophrenia patients and their first-degree relatives. Neuropsychologia 2002;40:2314–24.
4. Joseph MH, Datla K, Young AM. The interpretation of the measurement of nucleus accumbens dopamine by in vivo dialysis: the kick, the craving or the cognition? Neurosci Biobehav Rev 2003;27:527–41.
5. Kapur S. Psychosis as a state of aberrant salience: a framework linking biology, phenomenology, and pharmacology in schizophrenia. Am J Psychiatry 2003;160:13–23.
Sylvain Grignon, MD, PhD
Mikael Trottier, Medical Student
Sherbrooke, Quebec
|
