What is Capgras Syndrome?
Capgras syndrome is a delusional misidentification disorder in which a person holds the fixed, false belief that a close friend, family member, or significant other has been replaced by an identical-looking impostor 1, 2.
Core Clinical Features
The syndrome is characterized by:
- Delusional conviction that familiar persons (most commonly parents, spouses, or close relatives) are physically identical but psychologically distinct imposters
- Stability of the delusion despite clear evidence contradicting the belief
- Most frequently misidentified: Parents (84.2% in pediatric cases), spouses, and close family members 3
- Associated symptoms: Persecutory delusions (63.1%), auditory hallucinations (42.1%), aggression (31.5%), and depression (21.0%) 3
Underlying Conditions
Capgras syndrome occurs across multiple diagnostic categories 4:
Psychiatric Disorders
- Schizophrenia spectrum disorders (most common, 47.3% in pediatric cases) 5, 3
- Paranoid schizophrenia specifically shows high association 5
- Schizoaffective disorder
- Brief psychotic disorder 6
Neurodegenerative Diseases
- Dementia (particularly in elderly patients) 1, 7
- Frontotemporal dementia with selective anterior left temporal lobe atrophy 7
- Lewy body dementia 8
- Alzheimer's disease 4, 9
Neurological Conditions
- Traumatic brain injury with bilateral frontal and right hemisphere pathology 10
- The syndrome may represent a form of reduplicative paramnesia sharing the same pathologic substrate 10
Neurobiological Basis
The syndrome is associated with:
- Bilateral frontal lobe dysfunction combined with right hemisphere pathology 10
- Bilateral frontal and temporal slowing on quantitative EEG 7
- Deficits in naming, executive function, and long-term memory 7
Epidemiology
- Occurs in both men and women across various psychotic states 2
- Median age in pediatric cases: 15 years (60.5% male) 3
- Relatively uncommon in adolescent-onset psychosis 6
- Considered rare overall but may be underrecognized 5
Clinical Significance
The syndrome has significant negative effects on patients and caregivers due to its complex presentation and profound impact on relationships 9. The delusional belief can lead to:
- Rejection of actual family members
- Aggressive behavior toward perceived imposters
- Severe disruption of family dynamics
- Caregiver burden and distress