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Jyotirmoyee Patnaik
Kanak Manjari Institute of pharmaceutical Sciences
Rourkela, Orissa

During the past 80 years, delusional misidentification syndromes (DMS), especially the Fregoli a syndromes, have posed challenges to mental health professionals due to a lack of comprehensive understanding of the syndromes and a lack of effective treatment. During the past two decades, neurophysiological and neuroimaging studies have pointed to the presence of identifiable brain lesions, especially in the right front parietal and adjacent regions, in a considerable proportion of patients with DMS. Prior to the advent of such studies, DMS phenomena were explained predominantly from the psychodynamic point of view. Deficits in working memory due to abnormal brain function are considered to play causative roles in DMS.


The Fregoli delusion, or the delusion of doubles, is a rare disorder in which a person holds a delusional belief that different people are in fact a single person who changes appearance or is in disguise. The syndrome may be related to a brain lesionand is often of a paranoid nature; with the delusional person believing themselves persecuted by the person they believe is in disguise.

A person with the Fregoli delusion can also inaccuratelyreplicate places, objects, and events. This disorder can be explained by "associative nodes." The associative nodes serve as a biological link of information about other people with a particular familiar face (to the patient) This means that for any face that is similar to a recognizable face to the patient, the patient will recall that face as the person they know.

Levodopa treatment: Levodopa, also known as L-DOPA, is the precursor to several catecholamine, specifically of dopamine, epinephrine and norepinephrine. It is clinically used to treat Parkinson'sdisease and dopamine-responsive dystonia. Clinical studies have shown that the use of levodopa can lead to visual hallucinationsand delusions. In most patients, delusions were more salient than hallucinations. Over prolonged use of levodopa, the delusions almost occupy all of a patient's attention. In experimental studies, when the concentration of levodopa decreases, the number of reported delusions decreases as well. It has been concluded that delusions related to antiparkinsonian medications are one of the leading causes of Fregoli syndrome.

Traumatic brain injury: Injury to the right frontal and left temporo-parietal areas can cause Fregoli syndrome. Research by Feinberg, et al. has shown that significant deficits in executive and memory functions follow shortly after damage in the right frontal or left temporoparietal areas. Tests performed on patients that have suffered from a brain injury revealed that basic attention ability and visuomotor processing speed are typically normal. However, these patients made many errors when they were called to participate in detailed attention tasks. Selective attention tests involving auditory targets were also performed, and brain-injured patients had many errors; this meant that they were deficient in their response regulation and inhibition.

The symptoms of a Fregoli delusion are numerous:

  • Delusions and hallucinatory episodes
  • Lack of visual memory
  • Unable to properly monitor oneself
  • Lack of self awareness
  • Inability to properly control behavior and perform abstract thought
  • A record of seizures
  • Epileptogenic episodes

Treatments do exist for Fregoli disorder, and mostly utilize the antipsychotic type of drugs as well as antidepressant medication. At one time, tricyclic antidepressants were used, though following the discovery of their negative side effects treatment more often involves trifluperazine and modern antidepressants such as venlafaxine and fluoxetine. In addition to these, an anticonvulsant medication is sometimes prescribed.

The study of DMS currently remains controversialas they are often coupled with many psychological disorders (i.e. schizophrenia, bipolar disorder, obsessive compulsive disorder, etc.). Although there is a plethora of information on DMS, there are still many mysteries of the physiological and anatomical details of DMS. An accurate semi logical analysis of higher visual anomalies and their corresponding topographic sites may help elucidate the etiology of Fregoli's and other misidentification disorders.

Tibbetts, Paul. “Symbolic Interaction Theory and the Cognitively Disabled: A neglected Dimension." Jstor. Winter 2004. Web. 28 September 2011
Stewart JT (January 2008). "Frégoli syndrome associated with levodopa treatment". Mov. Disord. 23 (2): 308–9.
Feinberg TE, Eaton LA, Roane DM, Giacino JT (June 1999). "Multiple Fregoli delusions after traumatic brain injury". Cortex 35 (3): 373–87.
Pires-Barata, S., Gois, J. P., & da Silva, M. H. T. (2008). Fregoli's syndrome and traumatic brain injury.
Mojtabai R (September 1994). "Fregoli syndrome". Aust N Z J Psychiatry 28 (3): 458–62.
Silva JA, Leong GB, Miller AL (1996). "Delusional misidentification syndromes — Drug treatment options"



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