The delusional misidentification syndromes: strange, fascinating, and instructive

Area of Science:

• Psychiatry
• Neurology
• Psychopathology

Background:

• Delusional misidentification syndromes (DMS) are rare phenomena.
• These include Capgras, Frégoli, intermetamorphosis, and subjective doubles syndromes.
• DMS often co-occur and share a theme of the 'double' (sosie).

Purpose of the Study:

• To review hypotheses explaining DMS.
• To categorize DMS into hypo- and hyperidentifications.
• To emphasize the need for investigating organic contributions in DMS.

Main Methods:

• Literature review of delusional misidentification syndromes.
• Categorization based on hypo- and hyperidentification.
• Analysis of underlying etiological hypotheses.

Main Results:

• DMS are grouped by the concept of the double.
• Syndromes are classified as hypoidentifications (Capgras) or hyperidentifications (others).
• Hypotheses regarding their etiology are presented.

Conclusions:

• The presence of DMS suggests a need for thorough medical evaluation.
• Physicians should investigate potential organic contributions when DMS are observed.
• Understanding DMS is crucial for diagnosing and managing complex psychiatric and neurological conditions.