What is Capgras syndrome

Capgras syndrome is characterized by a delusional belief that a person, usually a close relative or friend, has been replaced by an imposter with very similar features as the original person ¹⁾. Capgras syndrome has been described in psychiatric and neurological (neurodegenerative and nonneurodegenerative) diseases.

Capgras syndrome was described almost a century ago named after the French psychiatrist who described “the illusion of doubles” ²⁾. Capgras syndrome is characterized by the recurrent and transient (ranging from minutes to months) belief that a person, usually someone closely related, has been replaced by an imposter. The imposter usually has features that are very similar to those of the original person ³⁾, although subtle physical differences are used to differentiate the original person from the imposter ⁴⁾.

Capgras syndrome is assumed to be a rare phenomenon initially reported to be associated only with psychiatric diseases, including paranoid schizophrenia ⁵⁾ and schizoaffective disorder ⁶⁾. However, more recently Capgras syndrome has also been described in neurological conditions including epilepsy ⁷⁾, in cerebrovascular disease ⁸⁾, after head trauma ⁹⁾, with pituitary tumor ¹⁰⁾, and especially in neurodegenerative diseases such as Alzheimer disease ¹¹⁾ and Lewy body disease ¹²⁾. However, it is unknown whether there are differences between Capgras syndrome that occurs in neurodegenerative compared with nonneurodegenerative diseases, or whether there are differences in Capgras syndrome when it occurs in different neurodegenerative diseases.

Capgras syndrome causes

The underlying neurologic cause of Capgras syndrome is unknown, some researchers theorize that it is caused by increased dopamine levels due to life stressors or medications, whereas others believe that brain lesions are a possible cause ¹³⁾. Capgras syndrome occurs most often in patients with schizophrenia, although it has also been reported in patients with dementia or epilepsy, as well as in patients who have experienced traumatic brain injury. Capgras syndrome is commonly associated with neurodegenerative diseases, especially Lewy body disease, where visual hallucinations always coexist ¹⁴⁾. In the absence of a neurodegenerative disease, the onset of Capgras syndrome occurs at a significantly younger age and can be associated with psychiatric disease, cerebrovascular events, and illicit drug use ¹⁵⁾.

more recently Capgras syndrome has also been described in neurological conditions including epilepsy ¹⁶⁾, in cerebrovascular disease ¹⁷⁾, after head trauma ¹⁸⁾, with pituitary tumor ¹⁹⁾, and especially in neurodegenerative diseases such as Alzheimer disease ²⁰⁾ and Lewy body disease ²¹⁾. However, it is unknown whether there are differences between Capgras syndrome that occurs in neurodegenerative compared with nonneurodegenerative diseases, or whether there are differences in Capgras syndrome when it occurs in different neurodegenerative diseases.

Capgras syndrome symptoms

Capgras syndrome is characterized by a delusional belief that a person, usually a close relative or friend, has been replaced by an imposter with very similar features as the original person ²²⁾.

Capgras syndrome treatment

There are limited studies on the efficacy of treatments for Capgras syndrome ²³⁾. Capgras syndrome is usually managed through treatment of the underlying disorders and typically involves antipsychotic medications. However, cognitive-enhancing treatments and nonpharmacologic strategies that diminish disorganization should be used in patients with dementia ²⁴⁾.