Aetiology of medically unexplained neurological symptoms Richard J. Brown PhD, ClinPsyD University of Manchester, UK Manchester Mental Health and Social Care NHS Trust
Overview 1. Are symptoms simply made up? 2. Dissociation theories 3. Psychodynamic / interpersonal concepts 4. Cognitive behavioural approach 5. An integrative framework 6. Conclusions
Are symptoms simply made up? Some people do feign symptoms for various reasons malingering involves deliberate simulation of symptoms for extrinsic gain (e.g. money, to avoid certain activities) factitious illness involves deliberate simulation of symptoms for intrinsic gain (i.e. to adopt the sick role ) However, diagnostic criteria for medically unexplained neurological symptoms (MUNS) state that symptoms are not intentionally produced
Main arguments / evidence There is no evidence that people with MUNS are more likely to feign symptoms than those with other conditions we should take self-reports at face value MUNS can be extremely disabling and damaging why would someone feign this when there are easier ways of achieving the same goals? Functional brain imaging suggests largely different neural correlates for simulated symptoms and MUNS (e.g. Ward et al, 2003; Stone et al, 2007; Cojan et al, 2009)
Earliest systematic theory of MUNS outlined by Janet (1889, 1907) Dissociation Based on the concept of désagregation or dissociation of mental systems
Dissociation: Basic principles People differ in the capacity to integrate their disparate mental activities into a coherent whole Deficits in this confer vulnerability to a breakdown of integration under conditions of extreme stress Traumatic memory fragments become separated (or dissociated) from awareness Symptoms generated by activation of traumatic memories a kind of somatic flashback or reliving
Dissociation: Recent approaches Dissociation concept revived and extended in a number of more recent models corticofugal inhibition (Ludwig, 1972) dissociation as a normal process (Hilgard, 1977) selective gating of processed material (Sierra & Berrios, 1999) somatoform dissociation theory (Nijenhuis, 2004) MUNS classified as dissociative in ICD-10 plus calls for similar in DSM-5
Evidence for dissociation High rates of trauma in MUS patients - MUS common feature of PTSD (e.g. Van der Kolk et al, 2003) - Elevated dissociation scale scores in some studies Recovery of forgotten material in non-epileptic seizure patients (Kuyk et al, 1999) Implicit perception studies (summarised in Kihlstrom, 1992) Some evidence for attentional dysfunction - executive tasks (e.g. Bendefeldt et al, 1976; e.g. Roelofs et al, 2002) - failure to habituate (e.g. Horvath et al, 1980; Rief & Auer, 2001) - ERP studies (e.g. Fukudu et al, 1996)
Evidence and arguments against dissociation Not all MUNS patients report trauma Mixed findings with dissociation scales Dissociation concept is poorly specified and over-extended evidence for two qualitatively different types of dissociation, only one of which is relevant here Integrative capacity yet to be operationalised
Psychodynamic / interpersonal concepts Originally proposed by Breuer & Freud (1893-1895) Defensive process whereby threatening material is rendered unconscious by conversion into physical symptoms
Psychodynamic / interpersonal concepts Now encompasses wider idea that symptoms serve a psychological function, where other ways of fulfilling those functions are not available or acceptable expressing distress but not focusing on the real issues solving otherwise insoluble emotional or social problems (e.g. stopping abuse) a form of care (or attachment) seeking behaviour (i.e. an interpersonal communication ) Deficit in ability to understand, regulate and express emotion ( alexithymia ) due to problematic early relationships
Main evidence and arguments Majority of evidence comes from clinical observation and case studies but these are open to interpretation Symptoms often preceded by stressful life events; some evidence of unspeakable dilemmas (Griffith et al, 1998) One study showing MUNS more likely to be rated as solving on-going conflict than organic symptoms (Raskin et al, 1966) Mixed findings in attachment research (e.g. Holman et al, 2008; Lally et al., 2010; Bouska et al, in prep.) Mainly negative findings in alexithymia research (e.g. Tojek et al, 2000; Bewley et al, 2005; cf. Bouska et al, in prep)
Cognitive behavioural theories (e.g. Sharpe et al, 1992; Deary et al, 2007) MUNS arise when relatively benign bodily events (e.g. emotional arousal, minor pathology, normal changes) are focused on and misinterpreted as evidence of illness resulting changes in behaviour / physiology create a vicious cycle process influenced by many different social, psychological and biological factors aetiology varies from one person to the next, although certain factors are common across people
BODILY EVENTS - Physical pathology - Physiological variations - Arousal & emotional disturbance Precipitating factors - Life events - Chronic stressors - Medical mismanagement SOMATIC EXPERIENCES ATTENTION TO EXPERIENCES Predisposing factors - Beliefs about illness - Personality (e.g. negative affectivity) - Childhood trauma - Experiences of illness INTERPRETATION OF EXPERIENCE AS ILLNESS / ABNORMAL BEHAVIOURAL - Checking - Help seeking - Avoidance - Other illness behaviour EMOTIONAL -Anxiety - Depression - Anger SOCIAL - Collusion with illness beliefs and behaviours - Stigma - Relationship problems COGNITIVE - Worry - Rumination - Mental checking - Cognitive distortions PHYSIOLOGICAL - Increased arousal - Deconditioning - Sleep disturbance - Muscle tension - Treatment side-effects From Brown (2006)
Appraisal of CBT model Good cross-sectional evidence for link between MUS and various biopsychosocial factors BUT very few studies on pseudoneurological symptoms little evidence concerning causality Can explain some MUNS but doubtful that all symptoms are due to misinterpretation of benign bodily events (consider e.g. paralysis, seizures, blindness)
An integrative framework All theories make clinical sense and have some support but none can account for all cases / data Theories often portrayed as mutually exclusive but are actually quite compatible with one another Possible to integrate core features of each within a common framework based on the idea that MUNS involve either a distortion in consciousness or a disturbance of volitional control
Core assumptions: An integrative framework consciousness is an interpretation of the world based on both sense data and memory most thought and action based on automatic activation of established programmes in memory disturbances in awareness and action control can arise when memory over-rides sense data during generation of conscious contents MUNS develop when rogue representations in memory become over-active and intrude into awareness (cf. dissociation theory)
Core assumptions: An integrative framework CBT model identifies factors that contribute to on-going activation of rogue representations motivational and interpersonal factors may also contribute to activation of rogue representations Model extends previous approaches by explaining how compelling symptoms can exist without underlying pathology or emotional trauma clarifying role of attentional processes in MUNS identifying tendency to experience distortions in somatic awareness as key risk factor
Conclusions (1) 1. There is no evidence that medically unexplained symptom patients are feigning and there are good arguments otherwise 2. Medically unexplained neurological symptoms remain poorly understood and are under-researched 3. Symptoms are likely to be multi-factorial; prior trauma is often present but is neither necessary nor sufficient factor 4. Each of the available theories offers something useful but none is complete; strongest evidence is for dissociation 5. It is possible to integrate different theories within a common framework based on cognitive principles
Conclusions (2) 6. Evidence is limited and further research is urgently needed 7. Future studies should: - carefully evaluate psychodynamic and interpersonal hypotheses given ratio of influence to actual evidence - extend research on predisposing, precipitating and maintaining factors in MUS to MUNS and look to evaluate causality rather than just correlation - explore role of dysfunctional attentional processes and individual differences in tendency for somatic distortion - use converging psychological, neuroscientific and social research methods - use large enough samples to allow inclusion of multiple variables, identification of sub-groups and firm conclusions
Further reading Brown, R. J. (2002). The cognitive psychology of dissociative states. Cognitive Neuropsychiatry, 7, 221-235. Brown, R. J. (2004). Psychological mechanisms of medically unexplained symptoms: An integrative conceptual model. Psychological Bulletin, 130, 793-812. Brown, R. J. (2005). Dissociation and conversion in psychogenic illness. In M. Hallett, S. Fahn, J. Jankovic, A. E. Lang, C. R. Cloninger & S. C. Yudofsky (Eds.), Psychogenic Movement Disorders: Psychobiology and Treatment of a Functional Disorder, pp.131-143. Lippincott, Williams & Wilkins. Brown, R. J. (2006). Medically unexplained symptoms. In N. Tarrier (Ed.), Case Formulation in Cognitive Behaviour Therapy: The treatment of challenging and complex cases, pp. 263-292. London: Brunner- Routledge.