What is the Role of Affect in Delusion Formation ? Vaughan Bell School of Psychology, Cardiff University Hadyn Ellis, Peter Halligan
Outline • Defining issues and phenomenology • Affect and delusions: Prevalence and co-occurrence • Affect and delusions, theoretical approaches: • Defence models of delusion • Direct models • Metacognitive role for affect ? • Neuropsychological correlates
What is a Delusion ? • The DSM defines a delusion as a belief that is: • False, based on incorrect inference about external reality. • Firmly sustained, despite what almost everybody else believes... • …and despite what constitutes incontrovertible and obvious proof or evidence to the contrary • The belief is not one ordinarily accepted by other members of the person's culture or subculture.
What is a Delusion ? • Every criterion of this definition has been criticised (Spitzer, 1990; Bell, Halligan & Ellis, 2003) • Including the assumption that delusions are beliefs (famously by Berrios, 1991) • But despite these defining issues there is clearly something to explain…
Case 1 A 22-year-old woman had the delusion that thoughts and feelings emanating from her mother’s unconscious were being carried in raindrops that fell on her air conditioner. When the raindrops hit the air conditioner they made a noise, and simultaneously these thoughts and feelings merged with her own unconscious. This merging had resulted in her own mental illness.
Case 2 AQ, a 36 year old woman with a previous diagnosis of bipolar affective disorder was admitted to hospital concerned that she was being “tracked by cameras” that had been placed around her house, that were transmitting images of her across radio, television and the internet. AQ had also experienced “beams of light” coming into her house which she believed were being controlled via the internet and were involved in her surveillance. After admission to the hospital ward, she voiced concerns about being watched by beams of light and was suspicious of the electric lights in her room. AQ was subsequently diagnosed as having a manic episode with psychotic symptoms.
Affective Disturbance in Delusions • Often difficult to pin-down as cross-sectional studies often group participants using concepts like psychosis or schizophrenia, rather than delusions per se. • However, despite these drawbacks, it is obvious there is a clear link between delusions and emotion.
Co-occurrence and Prevalence • Bowman and Raymond (1931) 58% of admissions with ‘manic-depressive psychoses’ had delusions.
Disturbed Affect in Psychosis • Experience sample of delusional patients: • Myin-Germeys et al (2001) intensity of delusion was associated with lower negative affect. • Psychotic outpatients: • Steer et al (2003) 18% were severely anxious on the Beck Anxiety Inventory. • Prodrome of paranoid schizophrenia: • Gourzis et al (2002) depressed mood (10%), anxiety (22%) and anger (48%) in prodrome (x = 14.6 months).
Delusions in Mood Disorder • General population survey: • Ohayon and Schatzberg (2002) 10.7% with feelings of worthlessness or guilt had delusions. • Depressed patients: • Cassano et al (2004) total manic items endorsed by unipolar patients predicted delusional ideation. • Delusional depression: • Seretti et al (2000) treating the mood disorder without antipsychotics reduces delusions.
Daniel Paul Schreber 1842 - 1911 Defence Models of Delusion • One of the first was from Freud (1911) who analysed Schreber’s “Memoirs of my Nervous Illness”. • Freud argued that delusions resulted from the sublimation of homosexual desire. • Unsurprisingly, psychological theory has since moved on, although the psychoanalytic angle is not dead. • Adler (1914) argued that paranoia occurs due to blaming others, to mask an inferiority-complex.
Bentall’s Attributional Model • Like Adler, Bentall (1994) argued that persecutory delusions are an extreme self-serving attribution bias (see Mezulis et al, 2004). • The result of trying to prevent low self-esteem thoughts entering consciousness by making excessive external-personal attributions for negative events. • This has now been reformulated (Bentall et al, 2001) to include mood effects of actual-self / ideal self discrepancies. • And relies on the distinction between explicit and implicit self-esteem.
Attribution / Self-representation 1 Events Positive Negative Internal bias High Ideal-self comparison Self-esteem / mood Internal bias Low Search self representations Stored self-knowledge Benign external situational Attribution Internal Beliefs about others (inc paranoia) External personal
Attribution / Self-representation 2 Events Positive Negative Internal bias High Ideal-self comparison Self-esteem / mood Internal bias Low Search self representations Stored self-knowledge Benign external situational Attribution Internal Beliefs about others (inc paranoia) External personal
Delusion Attribution / Self-representation 3 Events Positive Negative Internal bias High Ideal-self comparison Self-esteem / mood Internal bias Low Search self representations Stored self-knowledge Benign external situational Attribution Internal Beliefs about others (inc paranoia) External personal
Criticisms of Bentall’s Model • Largely, the poorly defined concept of self-esteem, which has probably led to equivocal findings in patient with persecutory delusions: • They have included: • High self-esteem (Candido and Romney, 1990) • High self / ideal-self discrepancy (Kinderman and Bentall, 1996) • Low self-esteem (Freeman et al, 1998)
Maher’s ‘One Stage’ Model • Maher (1988/99) has argued that delusions arise from normal reasoning applied to anomalous experience. • Anomalous experience. • Causing an arousal of anxiety, tension or fear. • Explanation of experience by normal reasoning. • Reduction in anxiety. • Persistence of explanation to defend against further anxiety.
Intolerance of Ambiguity • Studies have shown that intolerance to ambiguity is associate with delusional ideation. • For example in: • Delusional people with paranoid schizophrenia (McReynolds et al, 1964) • People with persecutory delusions (Bentall and Swarbrick, 2003) • People high in delusional ideation (Colbert and Peters, 2002)
Direct Models • These argue that emotion directly influence the formation and maintenance of delusions. • Rather than delusions being a response to unpleasant emotion (defence), or… • …being emotion being the result of a delusional belief (consequence).
Institute of Psychiatry Model • For non-affective psychoses the following is proposed (recent summary in Freeman and Garety, 2004) • Hemsley (1994) - memories of input regularities influence current perception. • These influences are weakened as per the stress-vulnerability model. • This disrupts assessment of the significance of incoming stimuli, causing novel or unexpected stimuli to enter consciousness. • The mismatch between predictions of the world and perception causes arousal.
Institute of Psychiatry Model • Similarly Gray (1982) Behavioural Inhibition Model, proposes that unexpected stimuli causes: • BI, arousal, increased attention to environment. • Depending on appraisal this might be experienced as anxiety or pleasurable arousal. • Garety and Hemsley (1994) - this might affect information processing, e.g. inferential reasoning biases in delusional patients. • Further delusional explanation may arise from the attempt to explain the seemingly unexplained arousal.
Shared Themes • For affective psychoses, Freeman and Garety (2003, 2004) note the similarity in themes between certain emotions and delusions Adapted from Freeman and Garety (2003)
Shared Themes: Criticisms • Connections between delusions and emotions (and vice versa) seem underdetermined and simplistic. • Some delusions seem not to have a reliable emotion (e.g. religious, lycanthropic). • Freeman and Garety dismiss religious delusions as being secondary elaborations of emotional states. • “They appear to be specific explanations that draw on pre-existing beliefs concerning religion” • Despite the fact that a delusional must not be “an article of religious faith”, i.e. not established dogma • Also ‘sensed presence’ (Cook and Persinger, 1997)
Shared Themes: Criticisms • Mono-delusional conditions (e.g. Cotard delusion) have also been cited as difficult to assimilate into this framework. • Standard explanation: • Person is depressed, perceptual input loses meaning due to lack of emotional modulation, lack of meaning leads person to believe they are dead. • Klee (2004) has argued that the emotion may not necessarily be that specific. • Why dead ? And not that they are, for example, made out of clay ?
Direct Models of Normal Belief • But Frijda et al (2000) have noted that: • “Emotions can awaken, intrude into, and shape beliefs, by creating them, by amplifying or altering them, and by making them resistant to change” • Clore and Gasper (2000) have noted a number of ways this may happen with normal belief. • Emotion as attention (selective attention bias) • Intensity and goal focus (positive feedback loop) • Emotion as information (feelings as evidence)
Emotion Belief Clore and Gasper (2000) Belief / attention / information cycle. Directs Modifies Information sampling Attention Guides
Affective Bias and Delusion • Good evidence that affect based attention / reasoning biases are increased in delusional patients compared to psychiatric / non-psychiatric controls, e.g: • Emotional stroop (Bentall and Kaney, 1989) • Threat word recall (Bentall et al, 1995) • Conditionals and syllogisms (Kemp et al, 1997) • Inferential reasoning (Dudley et al, 1997; although see Young and Bentall, 1997) • Threat perception / visual scan-paths (Phillips et al, 2000)
Reduction of goal space Intensity of feeling Importance of event Clore and Gasper (2000) “Attentional funnelling” effect of emotion. + + +
Goal Focus • For example Freeman et al (2000) found a high prevalence (100%) of safety behaviours in people with persecutory delusions. • As well as the well known bias for confirmatory evidence… • ...there seems to be a bias to avoid disconfirmatory evidence as well. • Delusional people avoid situations which would disconfirm their delusions.
Feelings as Evidence • Capgras delusion is a delusional belief that (usually) close relatives have been replaced by identical looking impostors. • Ellis et al (1997) showed that Capgras patients show a reduced automatic response to familiar faces. • i.e. they have a distorted ‘feeling of knowing’ (Bruce and Young, 1986) for faces. • Perhaps in a similar way to Damasio’s (1998) controversial somatic marker hypothesis. • Or, some other form of metacognitive process…
Affect as Metacognition ? • Might ‘feeling of knowing’ / ‘familiarity’ share processing or resources with aspects of affect ? • Nelson (1999) defines metacognition in terms of: • Monitoring – gathering information about cognitive state • Control – self-regulation process. • This has strong parallels with recent models of emotion.
Affective state / behaviour Appraisal / identification Stimulus + / - feedback Regulation Phillips et al’s (2003) Model • Koriat (2000) argues that metacognition can tap into implicit (experience based) knowledge and render it into qualitative subjective feeling useful for consciously directed behaviour. • And that behaviour outcome can feedback to modulate the subjective feeling.
Neuropsychological Evidence • Neuropsych evidence from Goel and Dolan (2003) RL PFC • They asked people to complete belief-congruent or incongruent syllogisms during fMRI. • Right lateral PFC was activated when belief-bias was overcome, consistent with its monitoring role. • VMPFC was activated when logical reasoning was overcome, a region implicated in affective processing. VMPFC • They suggest the effects of belief-bias on reasoning might be mediated through emotional processing.
Neuropsychological Evidence • Goel and Dolan (2003) conjecture that: • “the right PFC involvement in correct response trials is critical in detecting and / or resolving the conflict between belief and logic” • However, evidence from lesion studies and psychosis-continuum studies is not clear cut: • Lesion studies typically implicate R hem damage: • PFC and / or R hemisphere lesions in content-specific delusions (Galloy and Richardson, 1994) • Anosognosia (Venneri and Shanks, 2004) • Alzheimer delusions (Staff et al, 1999)
Neuropsychological Evidence • Although psychosis-continuum studies typically find relatively greater activation in the RH: • Magical ideation (Leonhard and Brugger, 1998) • Belief in ESP (Brugger et al, 1993) • Schizotypy (Kravetz et al, 1998) • And the imaging studies on people with persecutory delusions has shown mixed results on asymmetries and functional differences (Blackwood et al, 2001) • Although medial temporal and ventral striatal limbic areas seem important.
Summary • Affective disturbance is common in people with delusions, and delusions are common in people with affective disorders. • Two main theories have attempted to explain the role of affect in delusion formation: • Defence theories • Direct theories • There may be a metacognitive or epistemic role for affect that could explain its role in delusions.