Double trouble: Syndrome of subjective doubles‬

In a previous blog on Delusional Misidentification Syndromes, I briefly mentioned the rare syndrome of ‘subjective doubles’ (SSD). Also known as Christodoulou syndrome (after the Greek psychiatrist Dr. George Nikos Christodoulou who first wrote about the syndrome), SSD refers to individuals who have the belief that there are (one or more) doubles of themselves (i.e., doppelgangers) that carry out actions and behaviours independently and lead a life of their own but that have part or sometimes all of the SDD sufferer’s personality. If the sufferer believes that (some or all of) their personality has been transferred to their doppelganger, they may also experience depersonalization (i.e., a problem of self-awareness in which individuals feel they have little control over social situations and feel they are watching themselves act in a vague and dreamlike state. As with other DMSs, subjective doubles syndrome typically arises as a consequence of a mental disorder, brain injury (typically the right central hemisphere) or a neurological disorder. The Wikipedia entry on SSD cited the case of a man who became depersonalized after an operation and was convinced his brain had been placed into someone else’s head and then claimed he recognized the other person.

In the original paper on SSD in a 1978 issue of the American Journal of Psychiatry, Dr. Christodoulou described the case of a young 18-year-old woman who claimed that a female neighbour had (via an “elaborate transformation” involving “metapmophosis”) acquired all of her physical characteristics (“same face, same build, same clothes, same everything’) and become an identical double. To become her double, the female case study believed her doppelganger had used a mask, wig, and special makeup. Her female neighbour wasn’t the only doppelganger as the woman also claimed at least one other woman had become her doppelganger. In rare instances, there may be comorbidity with the Capgras delusion (another misidentification syndrome) and is then referred to ‘subjective Capgras syndrome’. In fact, there are a number of different sub-types of SDD. As the online Dictionary of Hallucinations notes:

“A subdivision of the syndrome of subjective doubles yields a ‘Capgras type’ (characterized by the delusional conviction that unseen doubles are active in the affected individual’s environment), an ‘autoscopic type’ (in which doubles of the self are perceived, ‘projected’ onto other people or objects, as in pareidolia), and a ‘reverse type’ (in which the affected individual believes to be an impostor or to be about to be replaced by someone else). The syndrome of subjective doubles is associated with various psychiatric disorders (notably the group of so-called schizophrenia spectrum disorders) and neurological disorders (notably disorders of the right parieto-temporal lobe). Conceptually and phenomenologically, the syndrome of subjective doubles constitutes the counterpart of a syndrome called ‘mirrored self-misidentification’, in which the affected individual is unable to identify his or her mirror image as oneself”.

Although most sources cite Dr. Christodoulou’s paper in the American Journal of Psychiatry as the first recorded case of SSD, he actually published a paper a year earlier in a 1977 issue of Acta Psychiatrica Belgica on the treatment of the syndrome of doubles. In this paper, Christodoulou used biological methods to treat 20 psychiatric patients with SDD or the related syndromes (Frégoli, intermetamorphosis, Capgras) aged 17 to 67 years of age. His patients were treated with ECT, antidepressants, neuroleptics, and antiepileptics (in some cases given singly whereas others were in combination). It was reported that:

“Results show that (a) the syndrome of doubles responded to various biological treatment methods; (b) in depression, it responded to tricyclic antidepressants; (c) in schizophrenia or organic psychosis, it usually responded to neurolytics; (d) in schizophrenia, it had more chances of responding to trifluoperazine given alone or in association with other psychopharmacological drugs; and (e) in certain cases, combination of antipsychotic treatment with treatment of coexisting organic dysfunctions appeared to be important”.

In another 1978 paper (in the Journal of Nervous and Mental Disease), Dr. Christodoulou described the course and prognosis of 20 patients with the syndrome of doubles (including Capgras syndrome, Fregoli syndrome, intermetamorphosis syndrome, and SDD – and presumably the same cases reported in the 1977 paper). He reported that the onset of the syndromes occurred either synchronously or at a later stage than the onset of the associated psychosis. In seven of the 20 cases, the syndrome failed to remit. In the remaining 13 cases, remission occurred either synchronously with or later than the remission of the basic psychosis. In all cases where there was comorbid depression, the syndromes cleared shortly after the successful treatment of the depressive illness. It was also noted that relapse of the basic psychotic condition in the setting of which the syndrome had originally developed was usually accompanied by the syndrome reappearing. In one of his most recent papers (from a 2009 issue of Current Psychiatry Reports), Christodoulou and three of his colleagues noted that:

“The delusional misidentification syndromes [including SDD] are rare psychopathologic phenomena that occur primarily in the setting of schizophrenic illness, affective disorder, and organic illness. They are grouped together because they often co-occur and interchange, and their basic theme is the concept of the double. They are distinguished as hypoidentifications (Capgras’ syndrome) and hyperidentifications (the other three syndromes [including SDD]).,,[We] propose that the appearance of these syndromes must alert physicians to investigate the existence of possible organic contributions”.

Compared to other misidentification syndromes, SDD appears to be relatively rare and is often comorbid with other similar conditions. For instance, in a 1986 issue of the Journal of Clinical Psychiatry, Dr. A.B. Joseph described the case of a 30-year old white male who had SDD along with paranoid schizophrenia, Cotard’s syndrome, Capgras delusion, and palinopsia (visual perseveration). Joseph concluded that cerebral dysfunctions in the confluence of the parietal, temporal, and occipital regions of the brain appeared to account for the disorders. Similarly, a 1996 paper in the journal Australasian Psychiatry, Dr. S. Atwal and Dr. M. Khan reported an unusual case of Capgras syndrome coexisting with three related syndromes (Fregoli syndrome, intermetamorphosis syndrome, and SDD).

In a more recent 1991 paper in the journal Psychological Medicine, Dr. H. Forstl and his colleagues examined the psychiatric, neurological and medical aspects of 260 cases suffering misidentification syndromes. Among the sample SDD was relatively rare as 174 cases had a Capgras syndrome misidentifying other persons, 18 a Fregoli syndrome, 11 intermetamorphosis, 17 reduplicative paramnesia and the rest had other forms or combinations of mistaken identification (including SDD). The most common comorbid disorders among those who misidentified themselves or other were schizophrenia (n=127; mostly paranoid schizophrenia), affective disorder (n=29), and organic mental syndromes including dementia (n=46). The authors reported that:

“The misidentification of persons can be a manifestation of any organic or functional psychosis, but the misidentification of place is frequently associated with neurological diseases, predominantly of the right hemisphere. Misidentification syndromes show a great degree of overlap and do not represent distinctive syndromes nor can they be regarded as an expression of a particular disorder. These patients deserve special diagnostic and therapeutic attention because of the possible underlying disorders and their potentially dangerous behaviour”.

Finally, I thought I would leave you with a paper from a 2005 issue of the journal Psychopathology that reported some extreme cases involving delusional misidentification syndromes (DMS) and the danger associated with them. Dr. M. Aziz and his colleagues reported on three cases with histories of paranoid schizophrenia tall of who developed DMSs:

“Two of them acted out on delusional thinking toward their sons. Case 1 managed to kill her son and Case 2 was caught twice trying to choke him. Our case reports suggest that the degree of threat perceived by the patient from the delusionally misidentified object is the most important factor in determining the patient’s response to the delusions. Alcohol and substance intoxication facilitated the patients’ acting out on their delusions, but did not explain the genesis of the delusions. There is a need to continue to study patients with DMS in order to provide opportunity for greater understanding of the psychopathology of DMS”.

Dr Mark Griffiths, Professor of Gambling Studies, International Gaming Research Unit, Nottingham Trent University, Nottingham, UK

Further reading

Atwal, S., & Khan, M. H. (1986). Coexistence of Capgras and its related syndromes in a single patient. Australasian Psychiatry, 20, 496-498.

Aziz, M.A., Razik, G.N., & Donn, J.E. (2005). Dangerousness and management of delusional misidentification syndrome. Psychopathology, 38(2), 97-102.

Christodoulou, G.N. (1977). Treatment of the syndrome of doubles. Acta Psychiatrica Belgica, 77(2), 254-259.

Christodoulou, G.N. (1978). Syndrome of subjective doubles. American Journal of Psychiatry, 135, 249-251.

Christodoulou, G.N. (1978). Course and prognosis of the syndrome of doubles. Journal of Nervous and Mental Disease 166, 73-78.

Christodoulou, G.N., Margariti, M., Kontaxakis, V. P., & Christodoulou, N. G. (2009). The delusional misidentification syndromes: strange, fascinating, and instructive. Current Psychiatry Reports, 11(3), 185-189

Dictionary of Hallucinations (2013). Syndrome of subjective doubles. Located at: http://hallucinations.enacademic.com/1828/syndrome_of_subjective_doubles

Enoch, D., Ball, H. (2001). Uncommon Psychiatric Syndromes (Fourth Edition). London: John Wright & Sons.

Forstl, H.A.N.S., Almeida, O. P., Owen, A. M., Burns, A., & Howard, R. (1991). Psychiatric, neurological and medical aspects of misidentification syndromes: A review of 260 cases. Psychological Medicine, 21, 905-910.

Joseph, A.B. (1986). Cotard’s syndrome in a patient with coexistent Capgras’ syndrome, syndrome of subjective doubles, and palinopsia. Journal of Clinical Psychiatry, 47, 605-606.