Delusions

A large and growing body of research in computational psychiatry draws on Bayesian modelling to illuminate the dysfunctions and aberrations that underlie psychiatric disorders. After identifying the chief attractions of this research programme, we argue that its typical focus on abstract, domain-general inferential processes is likely to obscure many of the distinctive ways in which the human mind can break down and malfunction. We illustrate this by appeal to psychosis and the social phenomenology of delusions.

In this paper, I will explore the irrationality of delusions through Wittgenstein’s notion of objective certainty. I will propose that objective certainties are constitutive epistemic norms, and that the specific irrationality of delusions can be captured in terms of the conflict with such constitutive norms. At the same time, however, I will critically examine various recent proposals to understand delusions as the loss of objective certainties, or even in terms of alternative objective certainties. Against these accounts, I will argue that (...) lost or alternative objective certainties cannot be used to understand delusional conflicts with constitutive norms, and that such lost or alternative certainties would even preclude attributing delusions to someone. Alternatively, I will argue that the proposed type of irrationality at stake in delusions implies that delusional speech has the form of avowals. (shrink)

Monothematic delusions are delusions whose contents pertain to a single subject matter. Examples include Capgras delusion, the delusion that a loved one has been replaced by an impostor, and Cotard delusion, the delusion that one is dead or does not exist. Two-factor accounts of such delusions hold that they are the result of both an experiential deficit, for instance flattened affect, coupled with an aberrant cognitive response to that deficit. In this paper we develop a new expressivist two-factor account of (...) delusion. In contrast to existing endorsement and explanationist accounts, which treat delusions as either explanations or endorsements of the contents of these disordered experiences, we hold that delusional beliefs have an expressive function: they characterize, in impressionistic terms, what the subject’s experience is like for them. We show how our account improves upon existing two-factor views in explaining the central features of monothematic delusions, in particular the way in which delusional subjects fall short of the ideal of rationality. (shrink)

Philosophy is witnessing an ‘Agential Turn’, characterised by the thought that understanding certain distinctive features of human mentality requires conceiving of many mental phenomena as acts, and of subjects as their agents. We raise a challenge for three central explanatory appeals to mental agency – agentialism about doxastic responsibility, agentialism about doxastic self-knowledge, and an agentialist explanation of the delusion of thought insertion: agentialists either commit themselves to implausibly strong claims about the kind of agency involved in the relevant phenomena, (...) or make appeals to agency which seem explanatorily redundant. The force of this ‘Agentialist Dilemma’ has been under-appreciated, and the agentialist literature does not contain a clear answer to it. Although we don’t aim to provide to a knockdown argument against the Agential Turn, we do suggest that the Agentialist Dilemma represents a significant challenge to the approach. However, we accept the fundamental critique motivating the Agential Turn, its rejection of a purely passivist and spectatorial conception of the human mind. We close by urging the recognition of a broader category of rational subjectivity, a category which includes states which are neither active nor passive, but nevertheless form part of a subject’s rational point of view on the world. (shrink)

Introduction: Cotard delusion—the delusional belief “I am dead”—is named after the French psychiatrist who first described it: Jules Cotard (1880, 1882). Ramachandran and Blakeslee (1998) proposed that the idea “I am dead” comes to mind when a neuropathological condition has resulted in complete abolition of emotional responsivity to the world. The idea would arise as a putative explanation: if “I am dead” were true, there would be no emotional responsivity to the world. Methods: We scrutinised the literature on people who (...) expressed the delusional belief “I am dead”, looking for data on whether such patients are reported as entirely lacking in emotional responsivity. Results: In numerous cases, patients with Cotard delusion are described as experiencing emotions including anxiety, fear, guilt, distress, euphoria and worry. Conclusions: We conclude that complete absence of emotional responsivity cannot be what prompts the delusional idea that one is dead. We propose that, in at least some cases, the idea “I am dead” comes to mind in response to symptoms of depersonalisation or derealisation, often present in cases of Cotard delusion, and give examples of Cotard patients with abnormalities in various neural areas that could be responsible for the presence of such symptoms. (shrink)

Delusions are standardly defined as attitudes that are not amenable to change in light of conflicting evidence. But what evidence do people with delusion have for and against it? Do delusions really go against their total evidence? How are the answers affected by different conceptions of evidence? -/- This chapter focuses on how delusions relate to evidence. I consider what delusions-relevant evidence people with delusions have. I give some reasons to think that people typically have evidence for their delusions, and (...) that the evidence they have against them is often overstated. I draw on this discussion to consider whether delusions are evidentially supported and epistemically rational. Finally, I discuss implications for the nature of delusion, responsibility, and treatment and suggest directions for future research. Throughout, the discussion is sensitive to different conceptions of evidence and rationality in epistemology. -/- A central upshot is that what we should say about the epistemic standing of delusions depends substantively on our positions in epistemology, in particular, on the debate between internalists and externalists about evidence. If we want clarity on the epistemic standing of delusions, we need to incorporate more sophisticated tools from epistemology. (shrink)

Anorexia nervosa involves seemingly irrational beliefs about body size and the value of thinness. Historically, researchers and clinicians have avoided referring to such beliefs as delusions, instead opting for the label ‘overvalued ideas’. I discuss the relationship between the beliefs associated with anorexia nervosa and the distinction between delusions and overvalued ideas, as it is conceived in both European and American psychiatric traditions. In doing so, I question the benefit of applying the concepts of delusion and overvalued idea to anorexia (...) nervosa and raise some issues with contemporary use of the Brown Assessment of Beliefs scale for assessing the level of delusionality associated with the disorder. (shrink)

The initial cause of Cotard delusion is pervasive dyshomeostasis (dysregulation of basic bodily function).This explanation draws on interoceptive active inference account of self-representation. In this framework, the self is an hierarchical predictive model made by the brain to facilitate homeostatic regulation. The account I provide is an alternative to two factor accounts of the Cotard delusion that treat depersonalisation experience as the first factor in genesis of the Cotard delusion. I argue that depersonalisation experience and the Cotard delusion are produced (...) by different breakdowns in the process of self-modelling. (shrink)

Popular two-factor accounts of thought insertion hold that this symptom of psychosis is caused by two elements working in tandem: an anomalous experience of some kind (the first factor) and a reasoning deficit or bias (the second factor). This chapter develops a very different alternative to explaining and treating thought insertion—one that views thought insertion as a form persecutory delusion. If this thesis is correct, clinical interventions for persecutory delusions may be successful for thought insertion as well. The chapter begins (...) by presenting several difficulties for two-factor accounts of thought insertion and for two-factor accounts of delusions more generally. It then discusses positive reasons for seeing thought insertion as a form of persecutory delusion. The positive case begins with reflection on first-person descriptions of thought insertion gleaned from online discussion forums. It continues by considering ways in which clinical diagnostic tools may create the appearance of deep differences between symptoms such as thought insertion and persecutory delusions where there are none. This case is bolstered by evidence for considerable variability in the content of delusions patients present with over time. Implications for the treatment of thought insertion are then considered. (shrink)

This work sets out to present how the notion of delusion may be understood (and extended) within the semantic framework of Robert Brandom's inferentialism. The mechanisms of reliability and community-oriented proprieties, among others, provide inferentialists with effective tools for understanding commitments (and so beliefs) in communities. These tools may be used to describe and assess both commitments that we might consider sound and commitments that we might consider delusional, both in terms of how they arise and in terms of how (...) they may be reinforced. Delusions are accordingly rendered in perspectival and normative terms, which is elaborated through a number of examples. The picture of how a delusional commitment may be understood, how it may be reinforced, and its character as community internal or external provide some interesting perspectives on delusions in shared social contexts, as well as how they may originate intractable conflicts and disconnects between sub-groups within a broader linguistic community. (shrink)

The cognitive science of belief is a burgeoning field, with insights ranging from detailing the fundamental structure of the mind, to explaining the spread of fake news. Here we highlight how new insights into belief acquisition, storage, and change can transform our understanding of psychiatric disorders. Although we focus on monothematic delusions, the conclusions apply more broadly. -/- .

Delusional perception designates a sudden, idiosyncratic, and often self-referential delusion triggered by a neutral perceptual content. In classical psychopathology, delusional perception was considered almost pathognomonic for schizophrenia. Since delusional perception has been erased from ICD-11 and always been absent in DSM, it risks slipping out of clinical awareness. In this article, we explore the clinical roots of delusional perception, elucidate the psychopathological phenomenon, and discuss its two predominant conceptualizations, i.e., Schneider’s well-known two-link model and Matussek’s lesser known one-link model. The (...) two-link model posits that delusional perception amounts to an abnormal interpretation of an intact perception, whereas the one-link model posits that the delusional meaning is contained within a changed perception. Despite their differences, both models stress that delusional perception is a primary delusion that takes place within an altered experiential framework that is characteristic of the psychopathological Gestalt of schizophrenia. We discuss the role of delusional perception in future psychopathological and diagnostic assessment and argue that such assessments must be conducted in comprehensive manner, eliciting the psychopathological context within which symptoms and signs are embedded. Finally, we discuss the compatibility of the two models of delusional perception with contemporary cognitive models on delusion and cognitive psychotherapeutic approaches. (shrink)

This chapter aims to get away from the ‘psychological attitude’ approach framing current philosophical discussion of delusion. We ask not what kind of attitude a delusion is – a belief or an imagination? Something else? – as if it were already clear what the ‘content’ of a delusion could be. We aim instead to shift attention to the question of the ‘object’ of delusions. What is delusion of? What is the object of this form of thinking? This focus on a (...) delusion’s object, over its attitudinal nature, is partly motivated by a desire properly to connect delusory thought with ordinary forms of fantastical thinking that are ubiquitous in the experiences faced by reflective humans in everyday life. We aim at securing a continuity, in a way that much extant discussion of delusion fails to, between delusory thought with more ordinary forms of thinking present in, for example, fantastical or magical thinking. Exploring familiar expressions of such thinking, especially those involved in love and loss, enables us to bring out the way in which such expressions convey forms of affective self-consciousness – that have the subject and her relations as an object – that are not naturally taken as reports liable to investigation as true or false. This raises the question about what how to think about what someone is doing when they give expression to a delusion should we think of them as expressing an attitude towards a truth or false content, or may they be doing something rather different? (shrink)

Can delusions, in the context of psychosis, enhance a person’s sense of meaningfulness? The case described here suggests that, in some circumstances, they can. This prompts further questions into the complexities of delusion as a lived phenomenon, with important implications for the clinical encounter. While assumptions of meaninglessness are often associated with concepts of ’disorder’, ’harm’ and ’dysfunction’, we suggest that meaning can nonetheless be found within what is commonly taken to be incomprehensible or even meaningless. A phenomenological and value-based (...) approach appears indispensable for clinicians facing the seemingly paradoxical coexistence of harmfulness and meaningfulness. (shrink)

The aim of this article is to analyze those theories that interpret misidentification delusions in terms of mentalization. The hypothesis under examination holds that a mentalization framework is useful for describing misidentification delusions when identification is thought to be partially based on mentalization. The article provides both a characterization and possible interpretations of such delusions, and possible relations between misidentification and mentalization are scrutinized. Whether the mentalization approach may explain or describe such kinds of mental disorders is considered, with the (...) conclusion that while this approach is unsatisfactory, there is some room for future improvement. (shrink)

The DSM-5 highlights two essential psychological features of anorexia nervosa (AN): recalcitrant fear of gaining weight and body image disturbance. Prominent accounts grant false beliefs about body weight and shape a central role in the explanation of AN behavior. In this article, we propose a stronger emphasis on recalcitrant fear. We show that such fear can explain AN behavior without the intermediary of a false belief, and thus without the associated explanatory burdens and conceptual difficulties. We illustrate how shifting the (...) emphasis from false belief to recalcitrant fear can supplement a number of different non-doxastic models of AN. (shrink)

Delusions have traditionally been considered the hallmark of mental illness, and their conception, diagnosis and treatment raise many of the fundamental conceptual and practical questions of psychopathology. One of these fundamental questions is whether delusions are understandable. In this paper, we propose to consider the question of understandability of delusions from a philosophy of language perspective. For this purpose, we frame the question of how delusions can be understood as a question about the meaning of delusional utterances. Accordingly, we ask: (...) “what meaning(s) can delusional utterances possibly have?”. We argue that in the current literature, there is a standard approach to the meaning of delusional utterances, namely the descriptive account which assumes that a delusional utterance “p” means that p is the case. Drawing on Speech Act Theory, we argue that solely relying on the descriptive account disregards essential ways of how linguistic meaning is constituted. Further, we show that Speech Act Theory can prove a helpful addition to the theoretical and clinical “toolbox” used for attempting to understand delusional utterances. This, we believe, may address some of the theoretical and clinical shortcomings of using only the currently predominant descriptive account. (shrink)

How many factors, i.e. departures from normality, are necessary to explain a delusion? Maher’s classic one-factor theory argues that the only factor is the patient’s anomalous experience, and a delusion arises as a normal explanation of this experience. The more recent two-factor theory, on the other hand, contends that a second factor is also needed, with reasoning abnormality being a potential candidate, and a delusion arises as an abnormal explanation of the anomalous experience. In the past few years, although there (...) has been an increasing number of scholars offering a variety of arguments in defence of Maher’s one-factor theory, these arguments have not been adequately addressed by two-factor theorists. This paper aims to address this gap by critically examining the arguments on three crucial issues: the intelligibility of delusions, the dissociation between anomalous experiences and delusions, and the empirical evidence of a second factor. I will argue that the Maherian notion of anomalous experience is not sufficient for explaining delusions and the two-factor theory is on the right track in its search for the missing factor in the aetiology of delusions. (shrink)

Kengo Miyazono, in his work Delusions and Beliefs, defends a teleo-functional account of delusions. In my contribution to this symposium, I question one of Miyazono’s motivations for appealing to teleo-functionalism over its main rival, dry-functionalism. Miyazono suggests that teleo-functionalism, unlike dry-functionalism, can account for the compatibility of the theses (i) that delusions are genuine doxastic states (doxasticism about delusions) and (ii) that delusions do not perform the typical causal roles of beliefs (the causal difference thesis). I argue, however, that there (...) are also ways for dry-functionalism to account for this compatibility. If what I have to say is correct, then Miyazono is perhaps too hasty—at least in one important respect—to opt for teleo-functionalism over dry-functionalism. Dry-functionalism has an equally good chance of satisfying some of Miyazono’s explanatory goals. (shrink)

The Spinozan theory of belief fixation holds that mentally representing truth-apt propositions leads to immediately believing them. In this paper, I explore how the theory fares as a defence of doxasticism about delusions (the view that they are beliefs). Doxasticism has been criticised on the grounds that delusions typically do not abide by rational standards that we expect beliefs to conform to. If belief fixation is Spinozan, I argue, these deviations from rationality are not just compatible with, but supportive of, (...) their status as beliefs. (shrink)

In chapter 3 of Delusions and Beliefs, Kengo Miyazono argues that, when delusions are pathological beliefs, they are so due to their being both harmful and malfunctional. In this brief commentary, I put pressure on Miyazono’s account of delusions as harmful malfunctioning beliefs. No delusions might satisfy the malfunction criterion and some delusions might fail to satisfy the harmfulness criterion when such conditions are interpreted as criteria for pathological beliefs. In the end, I raise a general concern about attributing pathological (...) status to single beliefs out of context, and gesture towards the idea of pathology as a failure of agency to which some beliefs can contribute but that can only be identified by considering the person as a whole. (shrink)

A team of professionals considers whether a patient in her early 50s is developing Alzheimer’s. The patient is not experiencing the memory symptoms typical of that disease, with so far a few years of sporadic attentional lapses as the predominant cognitive complaint. Her most dramatic symptom is her impression that two versions of her husband live with her. One is her real husband, the other a “fake.” There is no elaborated story about who the fake is or why he is (...) there, and there is little in the way of behavior consistent with the idea. To the patient, there is a vague sense that her husband doesn’t belong in the house, but no clearly articulated... (shrink)

Delusions are usually considered as harmful and dysfunctional beliefs, one of the primary symptoms of a psychiatric illness and the mark of madness in popular culture. However, in recent times a much more positive role has been advocated for delusions. More specifically, it has been argued that delusions might be an answer to a problem rather than problems in themselves. By delivering psychological and epistemic benefits, delusions would allow people who face severe biological or psychological difficulties to survive in their (...) environment - although this has obvious epistemic costs, as the delusion is fixed and irresponsive to compelling counterevidence. In other words, it has been argued that delusions are biologically adaptive. The adaptiveness of delusions has been compared by Ryan McKay and Daniel Dennett to a shear pin, a mechanism installed in the drive engine of some machines which is designed to shear whenever the machine is about to break down. By breaking, shear pins prevent the machine from collapsing and allow it to keep functioning, although in an impaired manner. Similarly, when delusions form, they would allow a cognitive or psychological system which is about to collapse to continue its functioning, although in an impaired manner. However, this optimistic picture of delusions risks being undermined by both theoretical and empirical considerations. Using Sarah Fineberg and Philip Corlett’s recent predictive coding account as a paradigmatic model of the biological adaptiveness of delusions, I develop two objections to it: principles of parsimony and simplicity suggest that maladaptive models of delusions have an upper hand over adaptive models; and the available empirical evidence suggests that at least some delusions stand good chances of being psychologically adaptive, but it is unlikely that they also qualify as biologically adaptive. (shrink)

The central hypothesis of this book, Delusions and Beliefs: A Philosophical Inquiry (Routledge, 2019), is that delusions are malfunctional beliefs (Chapter 1); they belong to the category of belief (Chapter 2) but, unlike mundane false or irrational beliefs, they fail to perform some functions of belief (Chapter 3). More precisely, delusions directly or indirectly involve some malfunctioning cognitive mechanisms, which is empirically supported by the two-factor account of delusion formation (Chapter 4).

In Delusions and Beliefs, Kengo Miyazono proposes an extended and convincing argument for the thesis that delusions are malfunctional beliefs. One of the key assumptions for this argument is that belief is a biological notion, and that the function of beliefs is a product of evolution. I challenge the thesis that evolutionary accounts can furnish an epistemologically satisfying account of beliefs because evolutionary success does not necessarily track epistemic success. Consequently, also delusions as beliefs cannot be explained in a satisfactory (...) manner by looking at beliefs’ evolutionary function. How can we then salvage the notion of delusions as epistemologically relevant malfunctioning beliefs? I propose that knowledge-first epistemology gives us a way out. Knowledge-first accounts argue that knowledge is more primitive than belief. That is, knowledge is not a kind of successful beliefs ; instead, beliefs are failed attempts at knowledge. Being a belief derives from the norms of knowledge. Explaining the epistemology of beliefs through the primitive norms of knowledge, we can also explain why delusions are malfunctional beliefs: The cognitive and psychological defects that produce delusions block the beliefs from becoming knowledge. Consequently, delusions are attempts at knowledge that have failed particularly badly. (shrink)

Philosophical Investigations, Volume 45, Issue 4, Page 528-539, October 2022.

In this chapter we review recent research in an area in which David Over has made an important contribution: reasoning in people with delusions. Delusional beliefs can be distinguished from the strong beliefs that everyone holds by the extra intensity with which they are held and their abnormally weak evidential basis, together with their tendency to disrupt an individual’s everyday functioning. However, non-clinical delusional ideation can also be found, where people tend to ‘jump to conclusions’ on the basis of apparently (...) inadequate evidence compared to controls. Procedures used to assess this apparent bias may induce artificial behaviours that are normally not seen, through their demand characteristics and stressor properties. Delusion-prone people often respond more strongly than controls to such stressors, which may account for their tendency to reach the end-point of the experimental trials earlier. Furthermore, there is evidence that this tendency may not be irrational after all: the conclusion apparently jumped to may be fully justified on probabilistic grounds. Evans and Over’s (1996) dual rationality theory provides a framework for interpreting delusional reasoning: the aberrant belief may be a rational response to an anomalous experience or exaggerated emotional reaction. (shrink)

Delusions are often portrayed as paradigmatic instances of incomprehensibility and meaninglessness. Here we investigate the relationship between delusions and meaning from a philosophical perspective, integrating arguments and evidence from cognitive psychology and phenomenological psychopathology. We review some of the empirical and philosophical literature relevant to two claims about delusions and meaning: delusions are meaningful, despite being described as irrational and implausible beliefs; some delusions can also enhance the sense that one’s life is meaningful, supporting agency and creativity in some circumstances. (...) Delusions are not incomprehensible representations of reality. Rather, they can help make sense of one’s unusual experiences and in some circumstances even support one’s endeavours, albeit temporarily and imperfectly. Acknowledging that delusions have meaning and can also give meaning to people’s lives has implications for our understanding of psychotic symptoms and for addressing the stigma associated with psychiatric conditions. (shrink)

The conscious experiences we have during sleep have the potential to improve our empathetic response to those who experience delusions and psychosis by supplying a virtual reality simulation of mental illness. Empathy for those with mental illness is lacking and there has been little improvement in the last decades despite efforts made to increase awareness. Our lack of empathy, in this case, may be due to an inability to accurately mentally simulate what it’s like to have a particular cognitive disorder. (...) Dreaming can help mitigate these deficits by placing the dreamer directly into a realistic virtual simulation and thus increase their capacity for empathy. Increasing empathy would go some way towards reducing the stigma and discrimination faced by people in this group. Recent work suggests that virtual reality can increase empathy towards a variety of marginalised groups, however, this technology is limited in its ability to simulate mental illnesses such as delusions. Dreams, however, are at times virtual reality delusion simulators. They can replicate, to a reasonable degree, delusions and psychosis, and through these experiences, we can learn ‘what it’s like’ to have these conditions. It is essential that we recognise these experiences for what they are, attempt to remember and reflect on them. Instead of disregarding dreams due to their unusualness and bizarreness, we can learn from these experiences and expand our understanding of the human condition and its many forms. (shrink)

Kengo Miyazono’s Delusions and Beliefs: A Philosophical Inquiry is an attempt to provide a unified account of the nature, pathology, and etiology of delusions. The strength of his book resides in the clarity of arguments and its consistent adoption of a biological explanation of delusions, based on teleo-functionalism about mental states. However, there are some weaknesses in each of his arguments regarding the nature, pathology, and etiology of delusions. Regarding the nature of delusions, teleo-functionalism makes it difficult to confirm that (...) delusions are beliefs. Regarding the pathology of delusions, I suggest that the existence of harmful malfunction is a necessary but not a sufficient condition for a belief to be considered pathological, and that additional evidence is needed to justify the separation of the belief and the holder’s personhood. Regarding the etiology, it is not reasonable to incorporate the prediction error theory into a kind of two-factor theory. Therefore, the details of his arguments require further modification. (shrink)

According to the Rationality Constraint, our concept of belief imposes limits on how much irrationality is compatible with having beliefs at all. We argue that empirical evidence of human irrationality from the psychology of reasoning and the psychopathology of delusion undermines only the most demanding versions of the Rationality Constraint, which require perfect rationality as a condition for having beliefs. The empirical evidence poses no threat to more relaxed versions of the Rationality Constraint, which only require only minimal rationality. Nevertheless, (...) we raise problems for all versions of the Rationality Constraint by appealing to more extreme forms of irrationality that are continuous with actual cases of human irrationality. In particular, we argue that there are conceivable cases of “mad belief” in which populations of Lewisian madmen have beliefs that are not even minimally rational. This undermines Lewis’s claim that our ordinary concept of belief is a theoretical concept that is implicitly defined by its role in folk psychology. We argue that introspection gives us a phenomenal concept of belief that cannot be analyzed by applying Lewis’s semantics for theoretical terms. (shrink)

In this paper I consider the project of offering an evolutionary debunking explanation for transparency in doxastic deliberation. I examine Nicole Dular and Nikki Fortier’s (2021) attempt at such a project. I suggest that their account faces a dilemma. On the one horn, their explanation of transparency involves casting our mechanisms for belief formation as solely concerned with truth. I argue that this is explanatorily inadequate when we take a wider view of our belief formation practices. I show that Dular (...) and Fortier overstate the extent to which adaptive non-evidentially supported beliefs are rare, and the implausibility of disjunctive evolutionary systems. They should allow a role for the non-truth directed behaviour of our mechanisms of belief formation. On the other hand, we might restrict the explanation offered by Dular and Fortier to the deliberative context, that is, we might understand them as allowing for non-evidential belief formation outside of the deliberative context, but as identifying the key to explaining transparency in the truth-directed evolutionary mechanisms as they operate in the deliberative context. However, this would land them on the second horn of the dilemma: we would then have no different an explanation to one I have offered elsewhere (2018), an explanation which Dular and Fortier explicitly put aside as engaged in a project different from their own. I finish by briefly considering some broader implications relating to explaining transparency, the nature of belief, and the prospects for pragmatism. I conclude that Dular and Fortier’s debunking explanation of transparency bestows an implausible role for truth in fixing our beliefs, or, if it doesn’t, then we simply have the restatement of a view explicitly disavowed by the authors. We are left, then, with an explanation we ought not want, or an explanation we already had. (shrink)

This article describes a case of a teenager with early complex trauma due to chronic domestic violence. Cannabis use triggered auditory hallucinations, after which the teenager was diagnosed with an acute schizophrenia-like psychotic disorder. Antipsychotic medication did not fully resolve symptoms. Eventually the teenager chose to self-medicate with LSD in order to resolve a suicidal condition. The teenager carried out six unsupervised LSD sessions, followed by an extended period of almost daily use of inhaled low-dose DMT. Psychotic symptoms were mostly (...) resolved after approximately one year. Subsequent cannabis use caused a transient relapse. -/- While his psychosis may have been due to cannabis use in the presence of a genetic predisposition, LSD and DMT did not promote psychotic symptoms in this case, and resolved the suicidal condition in one session. Additional high-dose LSD sessions and low-dose DMT sessions appeared to resolve the symptoms related to the early complex trauma. Alternatively, if psychosis is understood as a massive defense system resulting from early complex trauma, and if his psychotic symptoms were partially due to such trauma, psychedelics appeared to transcend this defense system, providing access to traumatic memories in order to allow for an integrative treatment effect. -/- Information was acquired from medical record excerpts provided by the patient, a semi-structured retrospective video interview, and follow-up interviews a year later. The present case suggests a need for further studies on the relationship between psychedelics and psychotic disorders, the feasibility of supervised vs unsupervised settings for various situations, and alternative therapeutic models for utilizing the hyperaware-hypersensitive state induced by psychedelics. With regard to self-treatment, a harm reduction approach should be adopted. Low-risk psycholytic self-treatment protocols could be developed for future use in public health care systems. (shrink)

In this article I explore the antinatalist view according to which it would be better if humans were to stop reproducing in order to contribute to the non-violent and voluntary extinction of the species as a whole. Not only is reproduction morally problematic in an already vastly overpopulated world, it is held that the human predicament can only be solved by slowly, but surely removing human presence altogether. Radical as this might sound, it must be noted that, far from a (...) villainous distaste of human life and happiness, this view emerges from a careful consideration of the vicissitudes of ordinary human existence. In spite of innumerous earlier attempts, suffering cannot be blotted out in life. What is called for, then, is something more conclusive: we can only remove suffering when we get rid of that which suffers. Any other attempt at solving the human predicament ultimately represents a merely cosmetic approach to problem-solving and the eradication of suffering. (shrink)

This thesis is set out as a collection of self-standing essays. Throughout these essays, I try to illuminate a number of controversies surrounding the way in which delusions are formed, and relatedly, their nature and epistemic standing. In Chapter 2, after an introductory chapter, I flesh out a new ‘endorsement’ approach to the Capgras delusion, the main idea being that the delusion is formed by endorsing the content of a metaphorical-perceptual state in which a loved one is represented metaphorically as (...) an imposter. In Chapter 3, I take issue with the idea, prevalent in the literature, that Bayesian accounts of inference in delusions are best characterised as versions of ‘explanationism’. Taking one such influential account as a test case, I argue that it is no more or less compatible with the endorsement alternative, which says delusions are acquired non-inferentially from experience. In Chapter 4, I examine a recent critique of predictive processing theories of delusions, according to which such theories suffer two limitations: they fail to explain why an agent believes something delusional as opposed to nothing at all or something else; they fail to explain how delusional hypotheses are generated in the first place. I suggest ways in which these concerns might be addressed. In Chapter 5, I consider how the Spinozan theory of belief fixation can improve the prospects of doxasticism about delusions. Doxasticism has been criticised on the grounds that delusions typically do not abide by rational standards which we expect beliefs to conform to. If belief fixation is Spinozan, I argue, these deviations from rationality are not just compatible with, but supportive of, their status as beliefs. In Chapter 6, I ask whether misidentification delusions formed via endorsement processes have any measure of perceptual justification. To give the best chance of getting a ‘yes’ answer, I address the question from the perspective of perceptual dogmatism, as this appears the best option if we are to grant at least defeasible justifiedness to MDs. I argue that, even so, MDs are completely unjustified. (shrink)

: Jennifer Radden argues that there cannot be delusional pain in depression, putting forward three arguments: the argument from falsehood, the argument from epistemic irrationality, and the argument from incongruousness. Whereas delusions are false, epistemically irrational, and incongruous with the person’s experience, feeling pain from the first-person perspective cannot be false or irrational, and is congruous with the person’s experience in depression. In this commentary on Radden’s paper, we share her scepticism about the notion of delusional pain, but we find (...) the arguments from falsehood and incongruousness ultimately unconvincing, given that delusions are not always false or incongruous. Rather, we develop the argument from epistemic irrationality, suggesting that, although some aspects of pain may exhibit informational plasticity and other characteristics shared by mental states that can be assessed for their rationality, the sensory component of pain does not. Keywords: Delusion; Pain; Epistemic Irrationality; Incongruousness; Falsity; Depression Riassunto: Jennifer Radden sostiene che non può esserci dolore delirante nella depressione, proponendo tre argomentazioni che si basano sulla falsità, l'irrazionalità epistemica e l'incongruenza. Mentre i deliri sono falsi, epistemicamente irrazionali e incongruenti con l'esperienza della persona, provare dolore in prima persona non può essere falso o irrazionale ed è congruo con l'esperienza di una persona che è depressa. In questo commento all’articolo di Radden, condividiamo il suo scetticismo nei confronti della nozione di dolore delirante, ma troviamo le argomentazioni basate sulla falsità e l’incongruenza in ultima analisi non del tutto convincenti, dato che i deliri non sono sempre falsi o incongrui. Piuttosto, sviluppiamo l’argomentazione basata sull’irrazionalità epistemica, suggerendo che, sebbene alcuni aspetti del dolore possano esibire plasticità e altre caratteristiche condivise da stati mentali che vengono valutati per la loro razionalità, la componente sensoriale del dolore non lo fa. Parole chiave: Delirio; Dolore; Irrazionalità epistemica; Incongruenza; Falsità; Depressione. (shrink)

INTRODUCTION: In accounts of the two-factor theory of delusional belief, the second factor in this theory has been referred to only in the most general terms, as a failure in the processes of hypothesis evaluation, with no attempt to characterise those processes in any detail. Coltheart and Davies attempted such a characterisation, proposing a detailed eight-step model of how unexpected observations lead to new beliefs based on the concept of abductive inference as introduced by Charles Sanders Peirce. METHODS: In this (...) paper, we apply that model to the explanation of various forms of delusional belief. RESULTS: We provide evidence that in cases of delusion there is a specific failure of the seventh step in our model: the step at which predictions from hypotheses are considered in the light of relevant evidence. CONCLUSIONS: In the two-factor theory of delusional belief, the second factor consists of a failure to reject hypotheses in the face of disconfirmatory evidence. (shrink)

People acquire new beliefs in various ways. One of the most important of these is that new beliefs are acquired as a response to experiencing events that one did not expect. This involves a form of inference distinct from both deductive and inductive inference: abductive inference. The concept of abduction is due to the American pragmatist philosopher C. S. Peirce. Davies and Coltheart elucidated what Peirce meant by abduction, and identified two problems in his otherwise promising account requiring solution if (...) that account were to become fully workable. Here we propose solutions to these problems and offer an explicit cognitive model of how people derive new beliefs from observations of unexpected events, based on Peirce's work and Sokolov's ideas about prediction error triggering new beliefs. We consider that this model casts light not only upon normal processes of belief formation but also upon the formation of delusional beliefs. (shrink)

Introduction: Delusions demand an explanation in terms of their neural, psychological, and sociological mechanisms. We must bridge these levels of explanation in order to understand and ultimately treat delusions. To this end, debates continue as to the number of contributing factors, how those factors interact, and their underlying computational mechanisms.Methods: One popular family of models suggests that two separate insults are necessary, a problem with perception and an independent problem with belief. In particular, new work proposes that the belief problem (...) entails a bias against disconfirmatory evidence - yielding the characteristic fixity of delusions. Here, we evaluate that claim, as well as explanations of delusions more broadly.Results: We suggest that such a bias may not explain enough of the variance in belief updating in delusional participants, and, more fundamentally, it might rule out specific accounts of delusions, since, such a bias might prevent them from forming in the first place, under particular assumptions about cognitive architectures.Conclusion: We suggest conceptualising delusions as an evolving uncertainty driven negotiation between beliefs and evidence, in which initial formation is fuelled by unexpected uncertainty, but, once formed, the delusion engenders new expectations about uncertainty that tune down updating but also facilitate the elastic assimilation of contradictory evidence. (shrink)

This paper explores how metaphorical thinking might contribute to an aetiology of florid delusions in psychosis. We argue that this approach helps to account for the path from experience to the delusional assertion, which, though relatively straightforward for monothematic delusions like the Capgras delusion, has always been difficult to account for in florid delusions in psychosis. Our account also helps to account for double book-keeping and the relative agential inertia of the belief.

Delusions are commonly conceived as false beliefs that are held with certainty and which cannot be corrected. This conception of delusion has been influential throughout the history of psychiatry and continues to inform how delusions are approached in clinical practice and in contemporary schizophrenia research. It is reflected in the full psychosis continuum model, guides psychological and neurocognitive accounts of the formation and maintenance of delusions, and it substantially determines how delusions are approached in cognitive-behavioural treatment. In this Review, we (...) draw on a clinical-phenomenological framework to offer an alternative account of delusion that incorporates the experiential dimension of delusion, emphasising how specific alterations to self-consciousness and reality experience underlie delusions that are considered characteristic of schizophrenia. Against that backdrop, we critically reconsider the current research areas, highlighting empirical and conceptual issues in contemporary delusion research, which appear to largely derive from an insufficient consideration of the experiential dimension of delusions. Finally, we suggest how the alternative phenomenological approach towards delusion could offer new ways to advance current research and clinical practice. (shrink)