title: Psychobiological characteristics of dissociative identity disorder: a symptom provocation study.
abstract: BACKGROUND
  Dissociative identity disorder (DID) patients function as two or more identities or dissociative identity states (DIS), categorized as 'neutral identity states' (NIS) and 'traumatic identity states' (TIS). NIS inhibit access to traumatic memories thereby enabling daily life functioning. TIS have access and responses to these memories. We tested whether these DIS show different psychobiological reactions to trauma-related memory.
  
  
  METHODS
  A symptom provocation paradigm with 11 DID patients was used in a two-by-two factorial design setting. Both NIS and TIS were exposed to a neutral and a trauma-related memory script. Three psychobiological parameters were tested: subjective ratings (emotional and sensori-motor), cardiovascular responses (heart rate, blood pressure, heart rate variability) and regional cerebral blood flow as determined with H(2)(15)O positron emission tomography.
  
  
  RESULTS
  Psychobiological differences were found for the different DIS. Subjective and cardiovascular reactions revealed significant main and interactions effects. Regional cerebral blood flow data revealed different neural networks to be associated with different processing of the neutral and trauma-related memory script by NIS and TIS.
  
  
  CONCLUSIONS
  Patients with DID encompass at least two different DIS. These identities involve different subjective reactions, cardiovascular responses and cerebral activation patterns to a trauma-related memory script.
authors.affiliation: Department of Biological Psychiatry, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands. a.a.t.s.reinders@med.umcg.nl
authors.forename: A A T Simone
authors.initials: AA
authors.lastname: Reinders
authors.forename: Ellert R S
authors.initials: ER
authors.lastname: Nijenhuis
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Quak
authors.forename: Jakob
authors.initials: J
authors.lastname: Korf
authors.forename: Jaap
authors.initials: J
authors.lastname: Haaksma
authors.forename: Anne M J
authors.initials: AM
authors.lastname: Paans
authors.forename: Antoon T M
authors.initials: AT
authors.lastname: Willemsen
authors.forename: Johan A
authors.initials: JA
authors.lastname: den Boer
mesh_terms: D000328:Adult; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000098:blood supply / Q000000981:diagnostic imaging / Q000502:physiology*; D002560:Cerebrovascular Circulation; D009105:Dissociative Identity Disorder / Q000503:physiopathology* / Q000523:psychology; D005260:Female; D006801:Humans; D007092:Imagination; D008568:Memory / Q000502:physiology*; D011939:Mental Recall / Q000502:physiology*; D008875:Middle Aged; D025341:Principal Component Analysis; D011877:Radionuclide Imaging; D012094:Repression, Psychology