Delusional thinking ) OBAL K OURTESY (C Beliefs about ICTURES P OLUMBIA .C RIVER D AXI T ROM F

VAUGHAN BELL,PETER HALLIGAN and HADYN

ELLIS on the sometimes fine line between normality and abnormality.

ARLY in his third month of office, from the that the assassination The sprawling and eccentric VALIS is a President Reagan was on his way would cause Jodie Foster, the actress from novel based on delusions resulting from his E to address a conference when John Taxi Driver (a film which Hinckley was own psychotic breakdown, which he drew Hinckley fired six gun shots at point blank obsessed with), to fall in love with him. on for much of his prolific career (see box). range, wounding the president and three of In the same year the award-winning author From these and many other examples, it his entourage. In the controversial trial that Philip K. Dick, whose books have been would appear that unusual or unlikely followed, three defence psychiatrists turned into major Hollywood films, such beliefs have significant consequences and successfully argued that Hinckley was not as Blade Runner, Total Recall and Minority continue to captivate the interest of many guilty, on the grounds that he was suffering Report, published one of his last books. of us. But to examine such claims we need to know what is meant by a delusion. How do delusions differ from other abnormal beliefs? Does the study of delusions provide PHILIP K. DICK a productive way of understanding beliefs? Many novels and short stories by Philip K. Dick contain elements from the delusions he suffered regarding identity and the nature of reality. Dick described many bizarre experiences and came to believe that human Defining issues development was controlled by an entity called VALIS (Vast Active Living Intelligence System) and that his Delusions are one of the most important perception of Orange County, California was an illusion disguising the fact that he was really living in first- constructs used by psychiatrists to diagnose century Rome.There were multiple reasons for Dick’s bizarre beliefs, given his share of trauma, phobias and patients who are considered to have lost drug abuse, but it is likely that many of the delusions he wrote about stemmed from psychotic episodes he touch with reality (Maher, 1988). For experienced as a sufferer and as an observer of others.This alone makes his work of great psychological Jaspers (1963), one of the founders of interest. However, Dick also seems to have some knowledge of contemporary psychology himself, modern , delusions constituted incorporating as he did the work of Penfield,Vygotsky and Luria (among others) into his stories. the ‘basic characteristic of madness’ despite being ‘psychologically irreducible’.

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foremost, a form of belief: a belief whose acceptance and subsequent behaviour can THE MARTHA constitute the grounds for insanity. But no justification is offered and the statement MITCHELL EFFECT itself amounts to a belief in delusions. Sometimes improbable patient reports are More explicitly, the standard definition erroneously assumed to be symptoms of mental characterises delusions as false, based on illness (Maher, 1988).The ‘ effect’ an incorrect inference about external reality referred to the tendency of and different from what almost everyone practitioners not to believe the experience of the else believes (APA, 1994). Other features wife of the American attorney general, whose such as degree of conviction and persistent reports of corruption in the Nixon imperviousness to persuasion do not set White House were initially dismissed as evidence delusions apart from other beliefs (Garety of delusional thinking, until later proved correct & Hemsley, 1994). by the Watergate investigation. Such examples demonstrate that delusional Delusions – An abnormal pathology can often lie in the failure or inability to belief by any other name verify whether the events have actually taken Despite differences in emphasis, most definitions consider two criteria to be place, no matter how improbable intuitively they significant when establishing a delusion: might appear to the busy clinician. Clearly, there falsifiability and bizarreness. Simply are instances ‘where people are pursued by the described, ‘bizarre delusions are generally Mafia’ or are ‘kept under surveillance by the impossible, whereas non-bizarre delusions police’, and where they rightly suspect ‘that their are generally improbable’ (Sedler, 1995, spouse is unfaithful’ (Sedler, 1995).As Joseph H. p.256). The DSM-IV distinguishes these Berke (1998) wrote, even paranoids have as follows: a non-bizarre delusion may enemies! For understandable and obvious involve situations that in principle could reasons, however, little effort is invested by occur in real life but are thought (by the clinicians into checking the validity of claims of psychiatrist) to be highly improbable and persecution or harassment, and without such therefore potentially falsifiable; a bizarre evidence the patient could be labelled delusional. More significantly, the detection of or fantastic belief, however, is considered delusions has ‘enormous implications impossible and therefore assumed to be for diagnosis and treatment, as well as one not normally held by others in the consulting room, or lies beyond the complex notions concerning responsibility, culture or society. forensic capabilities of the clinician. As prediction of behaviour, etc.’ (David, 1999). The problem with each of these pointed out by Young (2000), ‘many of the Yet, as pointed out by many commentators definitions lies not with the differential beliefs considered to be delusions do not (see Jones, 1999), the clinical usage of the distinction, but with the absence of agreed meet these criteria (or are not tested against term delusion and its distinction from other operational definitions as to how these them) in practice’ (p.47). This can have abnormal beliefs involve a host of semantic criteria are arrived at clinically. The DSM some curious consequences (see ‘The and epistemological difficulties. definition does not specify how one might Martha Mitchell Effect’, above). Predominant amongst these is our belief set about establishing the falseness or Accordingly, this falsity criterion has that delusions are (to a large extent) self- bizarreness of the belief; nor how one been rightly questioned (Spitzer, 1990). evident; that is, that they constitute a type could know whether the belief was the Moreover, it is unclear what level of of belief that (almost) everyone else would product of an impaired inference, such evidence would be required to consider recognise as pathological. This, however, as occurs in paranoid patients, who show a belief ‘incontrovertibly false’ and whether is more apparent than real, and is not even a tendency to jump to conclusions in judgements should be based on the reflected in the many different opinions situations requiring probabalistic reasoning ‘balance of probabilities’ or the more that surround the definition of the construct (Bentall, 1994). Here we turn to some stringent test of ‘beyond reasonable doubt’. (Berrios, 1991; Garety & Hemsley, 1994; specific problems. ‘Delusional’ beliefs, consequently, may not Spitzer, 1990). Indeed, David (1999) has be false (Heise, 1988) or even firmly suggested ‘there is no acceptable (rather Falsifiability Non-bizarre delusions sustained (Myin-Germeys et al., 2001). than accepted) definition of a delusion’ involve situations and events that could (p.17). occur in real life, such as believing that Bizarre beliefs The attribution that For most of us, however, these thorny one is being followed, infected, poisoned a delusion is bizarre is typically defined issues of definition can be sidestepped by or deceived by another. Therefore the in terms of beliefs considered not normally choosing to adopt the descriptive and ‘falsifiability’ criterion can mean that held by other members of a person’s widespread characterisation offered by psychiatrists are often required to make culture or society. This, however, often first the American Psychiatric Association’s judgements on claims of marital infidelity, involves the psychiatrist’s own evaluation Diagnostic and Statistical Manual of persecution or conspiracy in the workplace as regards the plausibility of the belief; Mental Disorders (DSM-IV). This (Jones, 1999), where the available relevant after which the psychiatrist considers established psychiatric nosology text evidence is either limited, cannot be whether it is one typically sustained by considers a delusion to be, first and ascertained within the confines of the the others in the person’s culture. Although

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conceptual basis for the criteria of THE THREE CHRISTS OF YPSILANTI falsification or impossibility clearly breaks In 1959 social psychologist Milton Rokeach brought together three schizophrenic patients in the same down under scrutiny. It is also problematic psychiatric ward in Ypsilanti,Michigan, all of whom suffered from the Messiah complex – each believed he because psychotic symptoms such as was Jesus Christ. Rokeach was interested in seeing whether these mutually exclusive delusions would delusions and hallucinations are not interact and affect the extent of conviction and content of each patient’s delusional beliefs. In his book inevitably associated with the presence Rokeach (1964/1981) records how each patient dealt with this conflict, one by avoidance, one by of a psychiatric disorder (Johns & van Os, relinquishing his delusion and the other by attributing the identity claims of his compatriots to mental 2001). Consequently, patients with illness.Whilst this study would be considered ethically dubious today, it was one of the most original DSM-IV-type delusions do not constitute forays into the study of psychopathology where the explicit aim was to inform normal belief processes. a homogeneous group. More often than not the decision about whether or not a belief is delusional both evaluations may be related, they need 2003). Consequently, religious beliefs, is made on pragmatic grounds Ð namely, not be. If, based on his or her own beliefs including praying to a deity, are not the evidential consequences of the beliefs and experience, the psychiatrist considers typically considered delusional, while including the extent of personal distress, the belief sufficiently bizarre, then believing and claiming that one is a deity potential or actual injury or social danger presumably a diagnosis of delusion can (see ‘The Three Christs of Ypsilanti’, generated by the belief. Sometimes the be made independent of ascertaining the above) or that one’s spouse has been decision may be simple – Cotard’s actual prevalence of the belief in the replaced (see ‘Capgras delusion’, below) delusion, a person’s belief that they are patient’s culture. typically are. dead, may be assessed differently from The DSM definition, however, clearly The existence of high levels of a delusion of grandeur such as believing assumes that the criterion of abnormality conviction in what might be considered that you are dating a famous TV star. or bizarreness should be obvious, given abnormal, unscientific or paranormal that the belief is one not ordinarily beliefs raises important questions for Can delusions tell us about accepted by other members of a person’s mental health workers when justifying ‘normal’ beliefs? culture or subculture. This is not the notion of bizarre beliefs on purely Notwithstanding difficulties with the necessarily a reliable strategy: many conceptual or statistical grounds. As standard psychiatric definitions, most studies of psychiatrists show poor inter- pointed out by French (1992), most beliefs people accept that normal beliefs perform rater reliability for ratings of bizarre beliefs are based upon ‘personal experiences an essential and fundamental process in (Flaum et al., 1991; Junginger et al., 1992). perhaps supported by reports of trusted establishing mental reference points from Moreover, most clinicians are not in a others, and the general cultural acceptance which to help explain and interact with the position to know or find out whether such that such phenomena are indeed genuine’. world. It is impossible to understand beliefs comprise those normally accepted, Although clinically important, the racism, prejudice, and political and except by direct comparison with those of his or her own peer group. One method of comparison is the use of large-scale surveys, but most clinical judgements on the prevalence of beliefs in society are not typically informed by empirical evidence. In fact, beliefs in unscientific or parapsychological phenomena are not statistically uncommon (see Della Salla, 1999), and were this criterion alone employed as a sufficient condition, then many of us at times might be classified as delusional (Moor & Tucker, 1979). Large-scale marketing research polls carried out in the UK and North America consistently reveal that significant numbers of people within society hold strong beliefs about the paranormal. For example, a 1998 UK survey found that 41 per cent of respondents believed in communication with the dead, and 49 per cent believed in heaven Ð but only 28 per cent in hell (‘Survey of paranormal beliefs’, 1998). Such surveys also reveal important

cultural differences in held beliefs. In many OBERTS Western countries opinion polls confirm R AVE

that large numbers believe in god(s) and D hold other paranormal beliefs (Taylor, If you believe Elvis works in a chip shop you have to reject the belief that he is buried at Graceland

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religious conflict without considering observed that over the past 20 years discrepancy in fundamental belief systems. a variety of cognitive models of belief CAPGRAS Fodor (1983) indicated that beliefs formation have drawn ‘empirical support comprise a ‘central’ cognitive process from evidence that delusions can be DELUSION and should be regarded as qualitatively elicited in normal individuals undergoing Following a car crash in September 1995 Alan different from the modular processes that anomalous experiences (Zimbardo et al., Davies became convinced that his wife of 31 years have been well exploited by cognitive 1981), the prevalence of delusions in died in the accident and had been replaced by neuropsychologists (Coltheart, 1999). The neuropathological disturbances of sensory someone with whom he did not want to share proposition, however, is not matched by experience (Ellis & Young, 1990), his life. Diagnosed as suffering from Capgras any clear consensus in neuropsychological reasoning deficits in deluded patients syndrome, Mr Davies was awarded £130,000 accounts of what constitutes the cognitive (Garety et al., 1991) and the tendency damages after it was claimed that his rare or neural mechanisms involved, the for deluded patients to make external psychiatric syndrome was caused by the crash evolutionary functions, or how such attributions following negative life events that he and his wife, Christine, had survived. beliefs can be changed and maintained. (Kaney & Bentall, 1989)’ (p.44). Despite suffering only minor physical injury he Jones (1999) describes beliefs as mental Recent developments from cognitive came to regard his wife, whom he now called forms that incorporate the capacity to neuropsychiatry have shown how detailed Christine II, as an imposter and became stressed influence behaviour and cognition and investigations of monodelusional conditions by any show of affection (de Bruxelles, 1999). (e.g. Capgras) can help to generate testable ‘beliefs in unscientific or theories of delusion, face recognition and normal belief formation (Ellis & Lewis, up explanations that are observationally parapsychological phenomena 2001). But this potentially rich vein of adequate versus those that fit within are not uncommon’ research for cognitive neuropsychiatry a person’s current belief set. However, (see Coltheart and Davis, 2000; Halligan a plausible process by which beliefs may & David, 2001) does not necessarily imply be integrated into such a belief set, or by govern the way people think and what that delusions are the primary source of which such a pre-existing set may they do. But the debate as to what defines psychopathology in patients diagnosed as influence how we generate beliefs about a belief or belief state rumbles on, and psychotic. Since most patients requiring our perceptual world, has not been widely some researchers have instead opted to psychiatric help have fully formed adopted. examine the ways in which damage or delusions by the time they are clinically Philosophers and social psychologists change to known cognitive processes can diagnosed, establishing the causal factors have attempted to piece together some of affect belief formation, as communicated responsible for the delusion is difficult. The this network Ð and with some success. or acted upon by patients diagnosed as neuropsychological or neurophysiological Quine and Ullian (1978) set out some suffering from delusions. Bryant (1997) abnormalities observed could just as easily philosophical principles by which a web of be interpreted as the product rather than the belief should operate. Of particular interest cause of these mental disorders. is their principle that beliefs are more However, if the formation of delusions easily shed, adopted or altered when the as abnormal beliefs is the product of resulting network disruption is minimal, selective but as yet unspecified cognitive and that beliefs are validated by their disturbance (e.g. in reasoning, thinking, relationships with existing beliefs. attribution) then studying delusions may Moreover, they claim that any belief inform our understanding of how this ‘can be held unrefuted no matter what, psychopathology impacts on normal by making enough adjustments in other belief systems. Either way, they provide beliefs’ (p.79) Ð though sometimes this a platform for elucidating the cognitive results in madness. Based on the idea that architecture of belief formation itself. not all beliefs (or links) are created equal empirical work has shown that particular Future directions from beliefs can be differentiated by the amount a useful past and strength of other beliefs, which are Despite the concept of delusion being relied on for justification (Maio, 2002). common parlance in psychiatry and One theoretical framework that we are society, it is only in the last 20 years that exploring in Cardiff is that provided by serious attempts have been made to define coherence theory (Thagard, 2000) when and understand the construct in formal considering dynamic models of belief cognitive terms (Bentall et al., 2001; processes in action. Our working model Coltheart & Davis, 2000; Garety & describes how active beliefs can be Hemsley, 1994). One area that has been evaluated for their acceptability by how either ignored or relegated to a mysterious well they cohere into existing belief sets. box in belief formation diagrams is the Beliefs and the constraints between them influence of our current ‘web of beliefs’ (for example, believing that Elvis is alive on the adoption or rejection of new beliefs. would constrain you to reject the belief Stone and Young (1997) strongly argued that he is buried at Graceland) can be given that belief formation may involve weighing values or weights. These allow an overall

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measure of coherence to be calculated distinction between meaningful and non- and delusional beliefs to be understood and also permit a quantitative measure meaningful information. Too much, as arising not simply from damaged of disruption when beliefs are added, however, could lead us to see significance biological mechanisms or information discarded or revised. and meaning in perceptual information that processing modules, but from cognitive Sensory input may be a constraint we might otherwise ignore, causing, beings firmly situated within their social in itself with the threshold for believing according to Spitzer, a range of unusual milieu. Such an approach might also better things obtained from your own senses and unlikely beliefs. allow us to treat patients with distressing (‘I believe it was raining this morning’) Given the heterogeneity and complexity beliefs, as well as provide a clearer insight considered higher than those taken on of the factors involved, not least of into how each of us comes to hold our own authority alone (‘I believe it was raining agreeing a common language to describe beliefs, be they viewed by others as during the Battle of Waterloo’). This and access the construct of abnormal mundane, profound or peculiar. hierarchy may partly explain why in some beliefs in question, it would seem sensible cases delusional beliefs can be adopted to adopt an eclectic approach to delusions ■ Vaughan Bell, Professor Peter Halligan over very short periods and with such Ð one that links understanding from and Professor Hadyn Ellis are in the conviction, and involve the sufferer neuroscience, cognitive and social School of Psychology, Cardiff University. dramatically revising other beliefs to psychology. This would allow ‘abnormal’ E-mail: [email protected]. cohere with their new-found preoccupation. Unusual experiences, which may accompany brain injury or mental illness, References may also give direct perceptual experience American Psychiatric Association paranormal: Do sheep and Comprehensive Psychiatry, 20, for unlikely or bizarre beliefs that cause (1994). Diagnostic and statistical goats think differently? 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