Cognitive models of dissociation

Transcription

1 Cognitive models of dissociation Richard J. Brown PhD, ClinPsyD University of Manchester, UK Manchester Mental Health and Social Care NHS Trust

2 Identity disturbance Somatic symptoms Depersonalization Derealization Amnesia Defence mechanism Divided attention Absorption Hypnosis DISSOCIATION Possession states Reduced awareness Flashbacks Made actions Intrusive thoughts/feelings Pseudohallucinations

3 Modal understanding of dissociation a disruption in the usually integrated functions of consciousness, memory, identity or perception of the environment (DSM- IV-TR; APA, 2000) Dissociative amnesia Dissociative fugue Depersonalization disorder Dissociative identity disorder (formerly MPD) DDNOS Conversion disorder NOT classified as dissociative in DSM-IV-TR

4 Modal understanding of dissociation Core symptoms Amnesia Depersonalisation Identity confusion/alteration Derealisation Commonly measured using the Dissociative Experiences Scale (Bernstein & Putnam, 1986) Often thought to be precipitated by trauma PTSD predicted by peri-traumatic dissociation

5 ICD-10 Dissociative (conversion) disorders Dissociative convulsions Dissociative motor disorders Dissociative anaesthesia Dissociative sensory loss Dissociative stupor Dissociative amnesia Dissociative fugue Dissociative trance/possession DDNOS Medically unexplained neurological symptoms (somatoform disorders in DSM-IV) Hysteria Somatoform dissociation Depersonalization disorder not dissociative in ICD-10 DID coded as dissociative disorder NOS

6 Two distinct types of dissociation (Holmes et al, 2005) Detachment An altered state of consciousness characterized by a sense of separation (or detachment ) from aspects of everyday experience depersonalization derealization emotional numbing peri-traumatic dissociation Compartmentalization A reversible deficit in the ability to deliberately control processes or actions that would normally be amenable to such control amnesia (reversible) unexplained neurological symptoms pseudohallucinations identity alteration

7 Detachment and conversion disorder Detachment An altered state of consciousness characterized by a sense of separation (or detachment ) from aspects of everyday experience depersonalization derealization emotional numbing peri-traumatic dissociation Panic without panic in some patients with PNES (Goldstein & Mellers, 2006) physical not emotional symptoms of panic attacks BUT detachment often absent in conversion disorder patients conversion symptoms uncommon in patients with depersonalization disorder

8 Compartmentalization A deficit in the ability to deliberately control processes or actions that would normally be amenable to such control reversible cannot be overcome by will occurs alongside evidence of intact functioning on a continuum from nonpathological to massively disabling Reversibility of amnesia following PNES (Kuyk et al, 1999) Implicit perception in conversion sensory loss (summarised by Kihlstrom, 1992) Intact motor function in conversion paralysis/ weakness (as in Hoover s sign)

9 Historical model (e.g. Janet, 1907) Deficit in attention creates vulnerability to breakdown of psychological integration when exposed to trauma Fragmentation leads to traumatic memories becoming separated (or dissociated) from awareness Symptoms generated by activation of traumatic memories a kind of somatic flashback or reliving Same process for hysterical and hypnotic phenomena detachment phenomena not seen as dissociative later suggested that memory fragments are kept from awareness for defensive purposes (Breuer & Freud, )

10 Neodissociation theories (e.g., Hilgard, 1977; Woody & Bowers, 1994; Woody & Sadler, 2008) Most processing managed outside of awareness by low level control systems EXECUTIVE EGO (Awareness and volition) Awareness/attention/volition (i.e., executive ego ) only needed for initial selection of lower systems most everyday functions are dissociated from consciousness (consider learning to drive a car) symptoms an extension of this Visual processing INPUT OUTPUT Auditory processing INPUT OUTPUT Motor processing INPUT OUTPUT

11 Pathological dissociation as a monitoring problem If behaviour is instigated by the executive (i.e. on purpose ) but is inconsistent with our goals then we experience it as having made a mistake BUT only if we know we did it on purpose! If we don t realise this (e.g. because we forget, we weren t paying attention, or we don t represent it in this way) then we experience it as happening to us Executive ego (Awareness and volition) Aware Output Inattention / amnesia Unaware Low level control structure Input

12 Pathological dissociation as a monitoring problem If behaviour is instigated by the executive (i.e. on purpose ) but is inconsistent with our goals then we experience it as having made a mistake BUT only if we know we did it on purpose! If we don t realise this (e.g. because we forget, we weren t paying attention, or we don t represent it in this way) then we experience it as happening to us Executive ego (Awareness and volition) A seizure is happening Output Inattention / amnesia Have a seizure Seizure control program Input

13 Pathological dissociation as a control problem Inhibition of the executive (e.g. by intense emotion) reduces control over low level systems, making the system vulnerable to stimulus-driven activation of unintended behaviours conversion phenomena similar to everyday action slips conversion phenomena similar to utilisation behaviour in some patients with frontal lobe damage Executive ego (Conscious volition) Inhibited Low level control structure Input Internal / external stimulus Output

14 Pathological dissociation as a control problem Inhibition of the executive (e.g. by intense emotion) reduces control over low level systems, making the system vulnerable to stimulus-driven activation of unintended behaviours conversion phenomena similar to everyday action slips and utilisation behaviour in some patients with frontal lobe damage Executive ego (Conscious volition) Inhibited I m having a seizure Seizure control program Input Output Seizure models in environment

15 Integrative cognitive model (Brown, 2002a,b, 2004, 2006; Brown & Oakley, 2004) Integrates dissociation concepts within broader biopsychosocial model of MUS assumes that symptoms reflect automatic activation of ideas about illness in memory (i.e., rogue representations ) process moderated by factors that (a) contribute to the activation levels of these rogue representations; and/or (b) compromise the individual s ability to inhibit them; symptoms are involuntary but may involve volitional processes in a number of ways (e.g., hypervigilance; selffocus; worry/rumination about symptoms; trying to control normally automatic behaviours; suppression)

16 Integrative cognitive model (Brown, 2002a,b, 2004, 2006; Brown & Oakley, 2004) EXECUTIVE ATTENTION (e.g. Worrying about and looking out for signs of possible seizures) INPUT Epileptic seizures encountered in self, others, the media etc. CREATION OF SEIZURE MODEL IN MEMORY ACTIVATION OF SEIZURE MODEL NON- EPILEPTIC ATTACK INTERNAL / EXTERNAL TRIGGERS (e.g. symptoms of arousal, stress etc.)

17 Take home messages 1. The term dissociation means different things to different people; mixed questionnaire findings probably reflect a tendency to conflate different definitions of dissociation within the same measure 2. If we define dissociation as the compartmentalization of information in the cognitive system then conversion symptoms are dissociative by definition 3. Trauma is not necessary for compartmentalization to occur but may be relevant in individual cases 4. Detachment is only relevant in a small proportion of cases of conversion disorder

18 Take home messages 5. Compartmentalization phenomena reflect the fact that much of behaviour/mental processing is performed automatically and outside of awareness symptoms can result from psychological processes without being produced on purpose (although voluntary processes can still be implicated indirectly) it is possible to explain conversion disorder without appealing to emotional conflict or psychological defence research / theory implicates attentional processes 6. There is far more theory than evidence! much more research is needed

19 References Bernstein, E. M., & Putnam, F. W. (1986). Development, reliability, and validity of a dissociation scale. Journal of Nervous and Mental Disease, 174, Brown, R. J. (2002). The cognitive psychology of dissociative states. Cognitive Neuropsychiatry, 7, Brown, R. J. (2002). Epilepsy, dissociation and nonepileptic seizures. In M. R. Trimble & B. Schmitz (Eds.) The Neuropsychiatry of Epilepsy, pp Cambridge, UK: Cambridge University Press. Brown, R. J. (2004). Psychological mechanisms of medically unexplained symptoms: An integrative conceptual model. Psychological Bulletin, 130, Brown, R.J. (2006). Different types of dissociation have different psychological mechanisms. Journal of Trauma and Dissociation, 7, Brown, R. J. & Oakley, D. A. (2004). An integrative cognitive theory of hypnosis and high hypnotizability. In M. Heap, R. J. Brown & D. A. Oakley, The Highly Hypnotizable Person: Theoretical, Experimental and Clinical Issues, pp London: Brunner- Routledge. Goldstein, L.H. & Mellers, J.D. (2006). Ictal symptoms of anxiety, avoidance behaviour, and dissociation in patients with dissociative seizures. Journal of Neurology, Neurosurgery and Psychiatry, 77, Hilgard, E. R. (1977). Divided consciousness: Multiple controls in human thought and action. New York: Wiley.

20 References Holmes, E., Brown, R. J., Mansell, W., Fearon, R. P, Hunter, E., Frasquilho, F. & Oakley, D. A. (2005). Are there two qualitatively distinct forms of dissociation? A review and some clinical implications. Clinical Psychology Review, 25, Janet, P. (1907). The Major Symptoms of Hysteria. NY: Macmillan. Kihlstrom, J. F. (1992). Dissociative and conversion disorders. In D. J. Stein & J. Young (Eds.), Cognitive science and clinical disorders (pp ). San Diego, CA: Academic Press. Kuyk, J., Spinhoven, P., & van Dyck, R. (1999). Hypnotic recall: A positive criterion in the differential diagnosis between epileptic and pseudoepileptic seizures. Epilepsia, 40, Woody, E., Bowers, K. (1994). A frontal assault on dissociated control. In: Lynn, S.J., Rhue, J.W. (Eds.), Dissociation: Clinical and Theoretical Perspectives. Guilford Press, NY, USA, pp Woody, E. Z., Sadler, P. (2008). Dissociation theories of hypnosis. In M.R. Nash & A.J. Barnier (eds). The Oxford Handbook of Hypnosis:Theory, Research and Practice. Oxford: OUP.