DNA paternity test resolving refractory Capgras syndrome
Article first published online: 28 SEP 2010
© 2010 The Authors. Psychiatry and Clinical Neurosciences © 2010 Japanese Society of Psychiatry and Neurology
Psychiatry and Clinical Neurosciences
Volume 64, Issue 5, page 589, October 2010
How to Cite
Chen, C.-J., Chiu, H.-J. and Lin, Y.-C. (2010), DNA paternity test resolving refractory Capgras syndrome. Psychiatry and Clinical Neurosciences, 64: 589. doi: 10.1111/j.1440-1819.2010.02127.x
- Issue published online: 28 SEP 2010
- Article first published online: 28 SEP 2010
- Received 26 February 2010; revised 13 June 2010; accepted 4 July 2010.
CAPGRAS SYNDROME IS characterized by a delusional belief that a close person has been replaced by an imposter.1 Some patients with this unusual syndrome demonstrate limited responses to pharmacotherapy or electroconvulsive therapy. However, further treatment strategies are rarely discussed for this refractory population. Currently the DNA paternity test is the gold standard for identification of biological paternity. We report a patient with refractory Capgras syndrome, which resolved after the introduction of a DNA paternity test.
A 27-year-old, single, high-school-educated Taiwanese man suffered from Capgras syndrome from the age of 24 years. He believed that his uncle was impersonating his father, and had murdered his real father and grandfather, and then seduced and married his mother. The mental status examination was normal except for this systemic delusion. His extroverted and amiable premorbid personality and fair premorbid interpersonal relationships excluded cluster A personality traits. Intelligence tests revealed a full IQ of 84. The diagnosis of delusional disorder was made by two psychiatric specialists. Such delusion did not respond to two antipsychotic agents (15 mg/day of haloperidol and then 4 mg/day of risperidone, doses were not increased due to intolerance of side-effects).2 Therefore, the patient had been hospitalized for 4 months because of persistent risk of violence toward his parents. After negotiating with his family and his psychiatric doctor, the patient requested to undergo a DNA paternity test. His delusion resolved soon after the result proved their parentage. After 9 months of follow up, the dose of risperidone was tapered to 1 mg, and his condition remained stable. The patient provided informed consent for this paper.
Studies suggest that the DNA paternity test has at least 99.9% probability of paternity for not exclusion or 100% certainty of exclusion.3 Given the wide acknowledgement of strong credibility to settle legal disputes, it is generally trusted by people, especially in Taiwan, where it is frequently presented in local television soap operas. As demonstrated in this case, the DNA paternity test can serve as an effective adjunctive management for refractory Capgras syndrome when used on appropriate occasions. Several practical issues regarding procedures, appropriate time, criteria for eligible patients, and possible adverse effects need further investigation. For example, our patient had a monosymptomatic delusion and had received a full-course antipsychotic treatment, thus might benefit because of less impairment in reality testing. This adjunctive management should be limited to refractory patients that have already received treatment, initiated by the patients' will, and performed after a careful evaluation to exclude delusion-based requests. More case studies are warranted in the future.
- 1Illusions des sosies dans un delire systematise chronique. Bull. Soc. Clin. Med. Ment. 1923; 11: 6–16., .
- 3Deoxyribonucleic acid (DNA) in tests of filiation, paternity and forensic medicine. Bol. Asoc. Med. P. R. 1989; 81: 130–133..