Capgras delusion

Overview

Capgras delusion, also known as Capgras syndrome, is a rare psychiatric disorder in which a person holds the irrational belief that someone close to them—typically a spouse, parent, or friend—has been replaced by an identical-looking impostor. It is classified as a delusional misidentification syndrome and is most often seen in individuals with underlying neurological or psychiatric conditions. Although uncommon, Capgras delusion can cause significant emotional distress and social dysfunction, both for the affected individual and their loved ones.

Causes

The exact cause of Capgras delusion is not fully understood, but it is believed to result from a disruption in the brain’s facial recognition and emotional processing pathways. Several conditions have been linked to the development of Capgras delusion, including:

• Neurodegenerative diseases: Most commonly seen in Alzheimer's disease and Lewy body dementia

• Brain injury: Especially trauma affecting the right hemisphere or temporal lobe

• Schizophrenia: Particularly the paranoid subtype

• Epilepsy: Temporal lobe epilepsy has been associated with transient misidentification episodes

• Stroke or brain tumors: Disruption of the brain areas involved in perception and recognition

One widely accepted theory suggests a disconnect between the visual recognition system (which identifies familiar faces) and the limbic system (which attaches emotional significance to them), resulting in recognition without emotional familiarity.

Symptoms

The defining symptom of Capgras delusion is the persistent belief that someone familiar has been replaced by a duplicate or impostor. Other symptoms and features may include:

• Accusations toward loved ones of being impostors

• Distrust or avoidance of the person believed to be replaced

• Emotional detachment or hostility toward the “impostor”

• Possible belief that multiple people have been replaced

• Co-occurring psychiatric symptoms such as hallucinations or delusions in patients with schizophrenia

• Memory problems or cognitive decline if associated with dementia

In some cases, the delusion may extend to pets, places, or objects, although this is less common.

Diagnosis

Diagnosis of Capgras delusion involves a comprehensive clinical evaluation to identify the underlying cause and rule out other conditions. The process may include:

• Psychiatric assessment: Detailed history of delusional beliefs, emotional state, and behavior

• Neurological examination: Assess for signs of dementia, brain injury, or seizures

• Cognitive testing: Evaluate for memory, attention, and executive function deficits

• Neuroimaging: MRI or CT scans to detect structural brain abnormalities or lesions

• Electroencephalogram (EEG): If epilepsy is suspected as a contributing factor

There is no specific test for Capgras delusion; diagnosis is made based on clinical features and context.

Treatment

Treatment of Capgras delusion focuses on managing the underlying condition and reducing the intensity of the delusional belief. Options include:

• Antipsychotic medications: Such as risperidone, olanzapine, or aripiprazole, especially in cases related to schizophrenia

• Cholinesterase inhibitors: For patients with dementia, to improve cognition and reduce delusional thinking

• Cognitive-behavioral therapy (CBT): May help challenge irrational beliefs and improve insight in some cases

• Supportive psychotherapy: To help patients cope with distress and strengthen interpersonal relationships

• Family education and support: To manage the emotional impact and promote safe, compassionate caregiving

• Environmental modifications: Ensuring consistency and reducing sensory overload may help ease symptoms in dementia-related cases

Prognosis

The prognosis of Capgras delusion varies depending on the underlying cause. In psychiatric cases such as schizophrenia, the delusion may respond to antipsychotic treatment but can be persistent or recur. In neurodegenerative diseases like Alzheimer’s, the delusion often progresses along with cognitive decline. For cases linked to brain injury or epilepsy, symptoms may improve with targeted neurological treatment. While Capgras delusion can be distressing and socially disruptive, early diagnosis, proper treatment, and a strong support system can significantly improve patient outcomes and caregiver well-being.