This is the belief that someone close to them, has been replaced by imposters. Patients admit there are no perceptual changes and that the altered person is physically identical to the original, with the changed person often said to have negative intentions towards the patient (Feinberg 2005). Cases have been presenting for more than a century now (Murray 1936). There has been some work in relating Capgras and Prosopagnosia – the latter is where people have difficulty recognising familiar faces, though other means of identification, e.g., tone of voice, is often intact. It is found with bilateral damage to the occipitotemporal cortex (Thompson 1980). It was originally felt to be explainable psychodynamically, but eventually cases with an organic basis were discovered (MacCallum 1973). Capgras delusion often presents via visual misidentification, but the presence of Capgras toward people who are not in immediate contact with the patient, argues for an explanation that involves more than face processing abnormalities. There are cases where auditory, somatic and visual misidentification has occurred in the blind (Herr 2003). Another blind 32-year-old male misidentified his mother (Rojo 1991).

 

Capgras syndrome is said to be rare and is typically found in those with schizophrenia. There are those who say that it is more common than most people believe. In this situation, diagnostic criteria tend to be broader e.g., misidentifying in a delusional way any familiar individual. In a sample of 612 patients, the number of those with Capgras went from four (on strict diagnostic criteria) to 18 people, using looser criteria. This latter group tended to black, female and schizophrenic, with a mean age of 39.9 years (Walter-ryan 1986).

 

An interesting point is that there are several patients, who describe transient episodes of Capgras syndrome. One lady had Capgras that lasted from an hour to 36 hours (Collins 1990). Another individual with dementia developed transient episodes of Capgras syndrome, which gradually become more and more frequent and permanent (Lucchelli 2007). There are cases of Capgras which have occurred in the very young, e.g., a 14-year-old developed Capgras and Fregoli syndrome (Yalin 2008) or Capgras alone (Schofield 1982), as well as in the very old (Burns 1985). Another interesting feature is that sometimes there are multiple imposter copies of an individual (O’Reilly 1987).

 

A study of five patients with Capgras compared them to five patients on antipsychotics and five healthy controls. All three groups had their skin conductance responses (SCR) measured in response to (un)familiar faces, as well as for a repeated tone. The two control groups had higher SCRs for familiar faces (as expected), but not the Capgras group, which was confirmed when the SCR scores were range corrected (SCR / largest SCR score). The SCRs for unfamiliar faces tended to be lower in the Capgras patients, which may indicate a more general hyporesponsiveness. The Capgras group had some face recognition impairment, generally in the context of normal intelligence and recognition for non-face stimuli (Ellis 1997).

 

An analysis of nine cases of Capgras syndrome found a mean age of 40.6 +/- 11.6 years. Most had organic mental illness or schizophrenia. These patients were identified from psychiatric inpatients, to give a prevalence of 2.5%. Five had physical problems and four had brain changes as shown by neuroimaging (Huang 1999).

 

Capgras can extend to inanimate objects (Sims 1993; Abed 1990, Castillo 1994), where the objects are often invested with a lot of personal significance. There are reports of Capgras to pressure cookers, jewellery, electronic receivers, etc. The first two objects had a lot of personal significance as represented by the patient’s view of her marriage (though the husband was not replicated) and the fourth example developed after an auditory experience (Bhide 1994). An Iranian woman believed her fridge, oven and clothes had been replaced, as well as her sons (Ghaffari-nejad 2005). It can occur for homes (Feinberg 2005). It has been associated with pictures of the patient, as well-being modality specific (Hirstein 1997). A 74–year-old man with paranoid delusions kept a list of all the supposed misdemeanours perpetrated against him including thefts, and, later, he felt that some of the stolen goods were replaced, e.g., screws, boots, razor etc. He also felt a policeman was the neighbour’s son. Several months later he was found to have a pituitary tumour on CT scan (Anderson 1988). A case study of a patient with schizophrenia with Capgras, noted how she felt that her belongings were being stolen and replaced with older goods. No mention was made of whether misidentification occurred, but it did seem to have a Capgras -like element (Atta 2006). Misidentification of animals has been documented, e.g., a woman with paraphrenia felt her canary was an imposter (Rosler 2001).

 

Just occasionally, the Capgras delusion may be applied to the sufferer themselves (Capgras to the self), e.g., a 24-year-old with schizophrenia felt she had changed into someone else (Chadda 1980), she was also experiencing erotomania and auditory hallucinations, though this lady seemed to have a different form of Capgras in that strangers, as well as familiar people, were replaced. Also, she had Fregoli-type symptoms in that she felt several strangers were her husband. Another lady with a history of paranoid psychosis felt she was being poisoned, and when she was presented with a bill for medical investigations, she claimed that the blood taken from her was not hers (Neppe 1992).

 

Depression is another mental illness that occasionally shows the Capgras delusion. Two patients with such a pattern, displayed higher verbal WAIS scores as compared to performance WAIS scores, deficits in verbal memory tasks (indicating problems with retrieval and self-monitoring) and impaired executive function and abstraction. This led the authors to suggest that perceptual difficulties may have been present, though one patient had hashimotos thyroiditis (Pachana 1999).

 

Schizophrenics with Capgras delusions, when compared to schizophrenics without Capgras, tended to show more frontal and cortical atrophy (Bourget 2004). A small case control study looked at three patients with Capgras syndrome and three paranoid schizophrenics. They were shown pairs of faces or objects, either horizontal of the midline, or to the left or right visual fields. They were then told to touch buttons to indicate whether the pictures were the same or different. When it came to objects, there was a suggestion that reaction times were faster in the right visual field, but there was no clear difference between the groups. When we look at faces, the schizophrenics showed faster reaction times in the left visual field but the Capgras patients showed faster times in the right visual field. Bilateral presentation of faces was associated with faster reaction times (Ellis 1993). Lesions tend to be found in the frontal, parietal and temporal lobes.

 

Numerous case reports have mentioned neurological damage being implicated in Capgras, for example in the posterior cingulate, precuneus and prefrontal cortex (Shiotsuki 2010). Capgras syndrome has been seen in Alzheimer’s disease; one case series described two patients who sometimes misidentified their own reflection and felt that there was another person in the reflection who was identical to themselves, but they misidentified the reflections as someone else (Molchan 1990; Mendez 1992). When a group of patients with Alzheimer’s were divided into those with and without Capgras syndrome, the former had lower mini mental state scores, higher scores on the blessed dementia scale and had a lower prevalence of other delusions. The presence of Capgras was also related to delusions of theft, the feeling that one’s home was not theirs, feeling of abandonment and paranoia. About seven to nine per cent of caregivers were misidentified (Harwood 1999). There have been cases where the appearance of Capgras signals the start of a dementia (Lipkin 1988).  When we consider the presence and absence of neurodegeneration, of 47 patients with Capgras, Capgras started later in those without neurodegeneration. In Lewy body dementia, Capgras tended to start three years after disease onset, as opposed to eight years in those with Parkinson’s disease dementia (Joseph 2007).

 

Other organic factors have a role to play in the development of Capgras. A 50-year-old woman with Capgras for her relatives developed right sided hemiplegia a few years later (Patange 1983). One case report of a patient with poor memory, vigilance and bradykinesia, developed visual hallucinations of a women he called ‘she’, who was identical to his wife, though he never confused them. This experience had a Capgras-like quality in that a person close to the patient was misidentified and it was restricted to the visual modality. MRI showed symmetric cortical atrophy, with a PET scan showing bilateral hypometabolism in the lateral / medial temporal regions, fusiform and parahippocampal gyri and peritemporal / fronto orbital regions (Carota 2008). Capgras has been associated with posterior watershed infarcts in a patient who developed cerebral ischemia after extracorporeal oxygenation (Dejode 2001), with right internal capsule infarcts (Collins 1990). A 30-year-old man, with no prior psychiatric history, developed AIDS around the age of 30. He felt that some of his friends had been replaced by members of the IRA and that they had kidnapped him and taken him to a garage (despite being in a hospital), where he was going to be used in communication. The EEG showed bilateral posterior theta waves and a CT showed wider sulci over the vertex and a possible resolving abscess in the right upper medial parietal lobe, the latter had gone in a later scan (Crichton 1990). Blindness with visual hallucinations occurred in a patient with Parkinson’s disease. He felt his wife had been replaced by several imposters (Hermanowicz 2002). There are even cases of it appearing after subarachnoid haemorrhage (Bouckoms 1986).

 

Capgras delusion has been found in those with metabolic abnormalities, such as those with pseudoparathyroidism (Preskorn 1978), in nephrotic syndrome (Collins 1990). A 9 year-old girl was given Chloroquine for malaria and 3 days later she felt her parents were dead and that the people claiming to her parents were not her parents. She recovered when Chloroquine was stopped, and antipsychotics were started (Bhatia 1988). There has been a case associated with hyponatraemia (Delaffon 2010). A 24-year-old woman with Wilson’s disease (a disorder of copper metabolism) presented with tremors in her right arm for three and half years and right leg for six months. For the last four months she displayed mental health changes and for the past month she felt her parents were imposters. She was started on D – pencillamine and L Dopa and her urinary copper levels rose and her symptoms gradually settled with antipsychotics. Cooper can lead to extrapyramidal symptoms, is important in the formation of myelin and is involved in Dopamine beta hydroxylase activity. There are case reports of schizophrenics improving with D – pencillamine (Sagar 1989). Hypothyroidism has been linked to Capgras syndrome (Madakasira 1981).

 

There are case reports of Capgras being associated with epileptic processes. A 28-year-old woman developed Capgras after starting disulfiram. She also displayed EEG abnormalities, which disappeared on clinical recovery (Daniel 1987). Another case describes a case of an 80-year-old man with a right frontal meningioma, who developed Capgras for self after suffering from seizures. These tended to be transient and gradually disappeared after each fit (Kim 1991). A 24-year-old female with a history of epilepsy, developed transient episodes of Capgras syndrome which lasted several weeks. Her Capgras disappeared after a left temporal lobectomy and hippocampoamygdalotomy (Kanemoto 1997). Another lady developed Capgras syndrome with persecutory delusions in the context of a fit, due to medication non-compliance (Joshi 2010). A 31-year-old woman developed hemiplegic migraine and thought that her left arm was replaced by someone else’s arm and developed Capgras to her husband, resulting in a patient with Capgras, asomatoagnosia, somatoparaphrenia and reduplication (Moreira 2010).

 

Head injury can lead onto Capgras (Weston 1971). Case reports have shown about a third of Capgras patients present with traumatic brain lesions (Ramachandran 1998). An interesting case describes a 17-year-old male who suffered a road traffic accident, resulting in numerous brain haemorrhages, leading to many cognitive impairments. He developed Capgras delusion to his father and would examine his father’s face closely when they met. He also experienced nihilistic delusions; the environment was altered, he felt that he was dead and was residing in hell (Butler 2000). Multiple sclerosis (MS) has been associated with Capgras syndrome. A 45-year-old married woman with MS displayed Capgras to her sons and husband, after becoming acutely unwell (Sharma 2009).

 

A very rare cause of Capgras syndrome appears to be Ushers syndrome, which is a genetic disorder vision and audition. A 56-year-old lady, who was deaf and blind, developed Capgras after stopping her medication. In this case, Capgras was seen in the touch modality and she felt that her husband and sons had been replaced (Waldeck 2001).

 

Psychotropics have also been associated with development of Capgras syndrome. A case report of a 74-year-old woman with a history of depression, described how she developed Capgras for her husband, shortly before her lithium levels rose above normal levels. Her symptoms resolved after lithium (and other medications) were stopped (Canagasabey 1991). A case series of three patients, who were given ECT for mood disorders, developed Capgras which remitted after the ECT was stopped. The author felt the organic changes that ECT induces may have been responsible (Hay 1986). Acute and chronic alcohol use has been implicated in development of Capgras delusion and can increase the violence associated with Capgras (Thompson 1993).

 

Capgras can also exist with other delusional forms, e.g., a 16-year-old girl developed delusions that her doctor was in love with her and she asked him repeatedly to marry her. Upon being told by him that he was married and not interested, she claimed he was an imposter (Gangadhar 1981). A similar co-occurrence of Capgras and de Clerambault was noted in a 32-year-old woman with paranoia. Capgras to her son developed about 18 months later, which eventually expanded to include others and soon she developed erotomania for a previous employer (Sims 1973). A 32-year-old woman, with Capgras syndrome, experienced being followed by someone who was possibly of Spanish royalty and this was interpreted as being reminiscent of Fregoli syndrome (Haslam 1973). There is a case of a lady with Capgras, Intermetamorphosis and erotomania. The Capgras extended to many people and she felt other people were actually her husband (Chadda 1990). Another case describes a 20-year-old woman who felt her father had slept with her and that her mother was an imposter (Pande 1991).

 

An association with somatic delusions has been reported. A 51-year-old woman with psychosis developed Capgras and somatic delusions after a hysterectomy and a 29-year-old man with what sounded like depression, had Capgras and a sense of something growing in his body. I would say that the latter syndrome was more Intermetamorphosis, rather than somatic delusions, as it involved the creation of another person inside him (Signer 1987). Another case described a 16-year-old girl who felt that she had excessive body hair and that her family were replaced by imposters (Kourany 1984). There is a case of a patient with Capgras, with coexisting grandiosity, erotomania and past morbid jealousy. Interestingly, his mother suffered from morbid jealousy (Kennedy 2000).

 

Capgras can also be found in folie a deux, e.g., a woman started to feel her father was an imposter after he stopped her marrying the man of her choice. Later, her younger sister developed similar delusions. The sister had a lower IQ, was more timid and subservient and both recovered after separation and treatment (Menon 1979). Another case involved a dominant mother, who began to develop delusional beliefs after the death of her husband in 1971, and a submissive daughter who gradually become more and more immersed in her mother’s delusional beliefs. The interesting factor here was the fact that the daughter probably had a cognitive impairment, which may have been implicated in the development of her delusional beliefs (Christodoulou 1995). It has also been found in a mother and her ten-year-old son (Hart 1989).

 

In a case series of 13 patients with Capgras, the target of the misidentification was a spouse in three cases, a sister in one case, a psychiatrist in another and one for their father – these were for those who were married / divorced / separated. For single patients; the figures were parent (3), sister (3) and cousin (1). Nine displayed Capgras to more than one person, three to inanimate doubles. In terms of negative feelings toward the those misidentified, less than 50% had such thoughts, 25% had positive feelings and 33% described feeling ambivalent to the target of the misidentifications (Kiriakos 1980). Another review of 11 patient with Capgras, found a mean age of 48 (range 28 to 67), nine were female and ten were married. They had either depression or schizophrenia, with an average of about five years to the development of Capgras syndrome from illness onset. Six described depersonalisation and derealisation and three had déjà vu. Most had EEG abnormalities, with imaging showing possible enlarged ventricles (Christodoulou 1977).

 

The nature of the misidentification can be quite hard to figure out sometimes; a case series of three patients with arteriosclerotic brain disease all had daughters who were recognised as such, but only during certain parts of the day when the patients would talk to their ‘real’ daughters about the other women who were present (MacCallum 1984).

 

Finally, I wish to mention a paper on the so-called Capgras for time. One patient felt it was 1984 and 1991 both at the same time, in the context of right hemisphere dysfunction and other misidentification syndromes. Another patient felt that time was replicated and that he had a dual existence, both in the present and the future (Joseph date unknown). A review of four cases with Capgras for time was presented, with the implicit assumption of there being a misidentification for time. The first case was a lady over 70 who felt that certain time periods were being repeated, which was a transient phenomenon. The second case was an elderly Alzheimer’s sufferer, who felt that all the days were replaced by a Sunday, though she did experience seven days to a week. The third case was a lady with a brain tumour who felt the week contained several extra Sundays, and finally, a schizophrenic felt that night and day had been swapped (Aziz 2005).

 

 

Looking at the dataset that I collected, out of a total of n=381 patients with capgras

• 304 cases only showed Capgras

• 223 were female, 157 were male

• 62 were never married, 165 were married and 25 widowed / divorced (n=252)

• 167 had a medical problem (n=195), 227 had previous psych history (n=268), 47 had a family psych history (n=110)

• 127 had children (n=142)

• 84 were aggressive (n=85)

• 14 cases with capgras also had fregoli, 19 had intermetamorphosis, 25 had duplication, 4 had mirror sign, 31 had copies, 29 had reverse misidentification.

• 117 had hallucinations (n=133), 244 had other non-misidentification delusions (n=378)

• 81 had cognitive impairment (n=87), 60 had EEG abnormalities (n=102) and 115 had neuroimaging issues (n=180)

• 170 were on psychiatric treatment (n=196), of which 144 responded

• 332 had misidentification directed toward others (n=340), 337 had misidentification toward humans (n=349). 137 had Capgras directed to their spouse, 95 to their parents, 34 to themselves and 78 to their children. Whilst 36 had Capgras directed towards objects