Delusional Misidentification syndrome is a group of delusional phenomena in which patients misidentify familiar persons, objects, or self, and believe that they have been replaced or transformed. Delusion is defined as a psychiatric disorder of thought content characterized by a belief, usually false, that is held with utter conviction despite evidence to the contrary and it cannot be explained by the educational or socio-cultural background of the person who holds the belief.

1. DELUSIONAL
MISIDENTIFICATION
SYNDROME
OLUGBENGA T. AWE
600L MB;BS STUDENT
BEHAVIORAL SCIENCE POSTING (2022)
UNIVERSITY OF ILORIN TEACHING HOSPITAL, ILORIN, NIGERIA.

2. OUTLINE
• INTRODUCTION
• EPIDEMIOLOGY
• ETIOLOGY
• VARIANTS
• PSYCHIATRIC MANIFESTATIONS
• MANAGEMENT
• ASSOCIATED DISORDERS
• CLINICAL SCENARIO

3. INTRODUCTION
• Delusion is defined as a psychiatric disorder of thought content characterized by
a belief, usually false, that is held with utter conviction despite evidence to the
contrary and it cannot be explained by the educational or socio-cultural
background of the person who holds the belief.
• Delusional Misidentification syndrome is a group of delusional phenomena in
which patients misidentify familiar persons, objects, or self, and believe that they
have been replaced or transformed.

4. EPIDEMIOLOGY
• Rare

5. ETIOLOGY
• Precise etiology not known.
• Neuroimaging has pointed to the presence of identifiable brain lesions especially
in the right frontal and temporal region and adjacent regions.
• According to Joseph Capgras, some of the people that had it had a prior brain
injury or head trauma.

6. ETIOLOGY
• Psychoanalytical View
• Believe that it is as a result of Oedipus/Electra complex (Freudian explanation)
• They try to resolve the guilt of their sexual desire by identifying them as impostor
• Psycho dynamic theory
• Some researches think that it results from organic cause leading to breakdown of
communication between the part of the brain that processes visual information and
the limbic system, which controls emotional response.

8. VARIANTS
• Capgras Syndrome
• Fregoli Syndrome
• Inter-metamorphosis
• Syndrome of Subjective double

9. CAPGRAS SYNDROME
• It is a delusional disorder in which a patient believes that a person closely related
to her has been replaced by a double.
• Patient believes that an impostor has replaced a close friend.
• Patient believes that the physical appearance of the impostor has not changed,
but the internal personality has changed.
• It is commoner in women, and the misidentified person is usually his partner or
another relative.
• It is named after Joseph Capgras, a French psychiatrist who first described the
disorder in a paper he co-authored with Reboul-Lachaux in 1923.
• It is seen in Schizophrenia, Lewy body disease, etc.

10. FREGOLI SYNDROME
• It is a disorder in which a person holds a delusional belief that different people are a
single person who changes his appearance in disguise, usually in order to persecute
the patient in some way.
• Patient believes that it is the physical appearance that changes, but the
internal/psychological personality did not change.
• It was named after an Italian actor, Leopoldo Fregoli, who was renowned for his ability
to make quick changes in his appearance during his stage acts.
• It is seen in Scizophrenia, Organic brain disease, etc.

11. INTER-METAMORPHOSIS
• It is a delusion in which patient believes that one or more individuals have been
transformed, physically and psychologically, into another person or people, or
that they have exchanged identities with each other.
• Patient believes that they can see others change into someone else both in
external appearance and in internal personality.

12. SYNDROME OF SUBJECTIVE DOUBLE
• It is a delusion in which patient believes that they have a double or Doppelganger
with the same appearance, but usually with different character traits, that is
leading a life of its own.
• Doppelganger is a German word which literary means double-walker i.e.
biologically unrelated look-alike.

13. PSYCHIATRIC MANIFESTATIONS
• Delusion
• Decrease Memory
• Hallucination
• Confusion
• Anxiety
• Irritability
• Fatigue
• Social withdrawal
• Ataxic gait
• Etc.

14. MANAGEMENT
• Detailed History (hx. suggests the variant, hx. of seizure, point to the underlining
pathology)
• Mental State Examination (poorly kempt, sad mood, disorder of thought content,
depending on the psychopathology)
• Physical Examination ( bruises, scar of previous head trauma)
• Investigation(FBC, E/U/Cr, ECG, FBS, brain CT Scan)
• Treatment

15. MULTIDISCIP
LINARY
BIOPSYCHOS
OCIAL
MULTILAYER
ED
INDIVIDUALI
ZED
MULTIDISCIP
LINARY
BIOPSYCHOS
OCIAL
MULTILAYER
ED
INDIVIDUALI
ZED
MULTIDISCIP
LINARY
BIOPSYCHOS
OCIAL
MULTILAYER
ED
INDIVIDUALI
ZED
MULTIDISCIP
LINARY
BIOPSYCHOS
OCIAL
MULTILAYER
ED
INDIVIDUALI
ZED
MULTI-
DISCIPLINAR
Y
BIOPSYCHO-
SOCIAL
MULTI-
LAYERED
INDIVIDUALI
ZED
• BIOLOGICAL THERAPY
• SSRI
• Antipsychotics
(Haloperidol,
Risperidone)
• BEHAVIOURAL PSYCHO-
THERAPY
• Acknowledge
their feelings
• Never argue or
correct
• Focus on creating
positive
emotional
experiences to
address
challenging
behavior
(impostor should
not be allowed
around)
• MULTIDISCIPLINARY
• Psychiatric
Doctors
• Psychiatric
Nurses
• Clinical
Psychologists
• Radiologist
• MULTILAYERED
• Layer by layer
• INDIVIDUALIZED
• Treat the patient
based on the
underlining
psychiatric
condition.
• SOCIAL THERAPY
• Family therapy
• Couple therapy

16. PUTTING ALL TOGETHER

17. POSSIBLE ASSOCIATED DISORDERS
• Scizophrenia (paranoid)
• Affective disorders
• Organic brain disorders (ischaemic brain damage)
• Traumatic brain injury.

18. CLINICAL SCENARIO
• Mrs C, a 58 year old woman brought to the psychiatry emergency room after she
called the police and reported there was a stranger in her house. She had a prior
history of psychiatric hospitalizations and was previously diagnosed with
schizophrenia(paranoid type). When the police arrived, she explained that her
husband was not her husband but was a stranger. She became argumentative and
combative toward the police officers. Due to her history of past psychiatric incidents
involving the police, she was brought to the psychiatric emergency room. At the time
of incidence, she was known to have consumed half a pint of brandy, and some of her
symptoms were thought to be alcohol-related. When evaluated in the emergency
room, she reported her distress was due to the impostor that had recently been
substituted for her husband and that the impostor made her life miserable…

19. REFERENCES
• http://www.slideshare.net/indhumadhav/capgras-syndrome-
57917752?from_m_app=android
• Kirov G, Jones P, Lewis SW. Prevalence of delusional misidentification syndromes.
Psychopathology. 1994;27(3-5):148-9. doi: 10.1159/000284862. PMID: 7846230.
• Textbook of Understanding Psychiatry
• wikipedia

20. THANK YOU FOR YOUR ATTENTION