In this thesis I argue that our philosophical account of the nature and norms of belief should both inform and be informed by our scientific understanding of monothematic delusions. In Chapter 1, I examine and criticise standard attempts to answer the question “What is delusion?” In particular, I claim that such attempts are misguided because they misunderstand the kind of term that “delusion” is. In Chapter 2, I look at the nature of explanation in psychology and apply it to delusions. In particular I look at the constraints on a successful explanation of a person’s psychological state in terms of brain damage or dysfunction. I then propose, in Chapter 3, a way of understanding how delusions of misidentification arise. In particular, I criticise the standard view that they are formed via inference (in the relevant sense of “inference”) on the basis of anomalous experience. I draw on empirical work on object and individual tracking, on dreams, and on the Frégoli delusion, and argue that inference is not only un-necessary, but is actually often bypassed in humans, for judgments of identification. The result is a non-inferential file-retrieval view. On certain views of belief, this would mean that the Capgras delusion lacks the right functional role to count as a genuine belief. In Chapter 4, I criticise such views of belief, and put forward a “downstream only” view. Roughly, something is a case of believing if and only if it disposes people to act in certain ways. I defend such a view against two serious and influential objections. In Chapter 5, I ask whether this means that the Capgras delusion can therefore safely be called a belief. I argue that there is a risk – even if one accepts the downstream only view of belief – that it still won’t count as a belief, as a result of the subject’s “incoherence” or “agentive inertia.” However, I then distinguish egocentric from encyclopaedic doxastic states. This opens the possibility that one can truly say that the subject has the egocentric belief, “This man is not my father”, but may fail to have the encyclopaedic belief, “My father has been replaced by an impostor”. It also demonstrates that the question “Are delusions beliefs?” has been approached in an unhelpful way by the main participants in the debate. This thesis is important because it shows the extent to which real-world phenomena can inform and be informed by central philosophical notions like belief. More precisely, it shows that the most plausible way of accounting for monothematic delusions involves abandoning both a strong normativism, and a discrete representationalism, about belief.

Despite a historical pessimism about the possibility of helping people with schizophrenia using psychological therapies, a great deal of progress has been made recently using cognitive-behavioural therapy (CBT) approaches. These treatments have been developed from changing understandings of schizophrenia, and focus on reducing the distress of psychotic symptoms through coping strategies and altering distressing beliefs. There is increasing evidence that suggests CBT may be helpful for a significant portion of people with psychosis. Limited information on the factors implicated in differing outcomes is available. The present study investigated factors differentiating individuals with good and poor outcomes on the basis of accounts of CBT for psychosis from eight therapist/client dyads. Four therapists and eight of their clients (two associated with each therapist) were interviewed about their experiences of CBT. Topics covered included, effect of the therapy, elements felt to be helpful and the therapeutic relationship. Interview data was analysed using a qualitative, "grounded theory", methodology. The analysis produced a number of major categories which differentiated clients who progressed and did not progress in CBT. These included ability to let go of distressing beliefs, logical thought, holding therapy, and presence of a shared goal. Overall, clients who progressed were better able to understand, hold and engage with ideas put forward by the therapist. Additionally, clients' views of CBT were positive and therapists and clients felt that non-specific benefits accrued from the therapy even when CBT specific progress did not occur. The results were consistent with previous studies suggesting that ability to consider disengaging from distressing beliefs are important in therapeutic progression. However further research is required to clarify the role of logical thought, holding therapy and therapeutic alliance in progress and in predicting outcome. Reasons considered for the inability to progress include, emotional investment in psychotic beliefs and information processing factors.

The aim of this thesis was to examine the impact of an identity delusion on autobiographical memory and develop a model of deluded autobiographical memory to guide future research in this area. Given the difficulty of studying identity delusions in isolation from other clinical disorders, this thesis presents six experiments that used hypnosis as a laboratory model of identity delusions. Chapter 1 reviews literature from three distinct areas, including delusions, autobiographical memory, and hypnosis. Chapter 1 reviews a model of the self and autobiographical memory proposed by Conway (2005) and outlines the value of using hypnosis instrumentally to model delusions of self. Chapter 2 presents two experiments that established hypnosis as a suitable paradigm for investigating identity delusions. These experiments examined the parameters of the hypnotic delusion and tested the impact of the delusion on self and autobiographical memory. Chapter 3 presents two experiments that continued to examine the characteristics of autobiographical memory during a hypnotic identity delusion. These experiments indexed the specificity, source, perspective, and qualitative features of autobiographical memories elicited during a suggested identity delusion. Chapter 4 presents two experiments that investigated memory processing during a hypnotic identity delusion. These experiments illustrated the shifting accessibility of autobiographical memories during a hypnotic identity delusion. Finally, Chapter 5 draws the empirical findings together to discuss the value of hypnosis as a technique for modelling identity delusions and the ways in which a hypnotic identity delusion influences autobiographical memory. Importantly, Chapter 5 proposes a model of deluded autobiographical memory that integrates Conway???s (2005) self-memory system with relevant aspects of Langdon and Coltheart???s (2000) two-factor theory of delusions. Using this proposed model as a framework, Chapter 5 discusses the clinical and theoretical implications of the findings from this thesis and suggests future research directions.

The aim of this thesis was to examine the impact of an identity delusion on autobiographical memory and develop a model of deluded autobiographical memory to guide future research in this area. Given the difficulty of studying identity delusions in isolation from other clinical disorders, this thesis presents six experiments that used hypnosis as a laboratory model of identity delusions. Chapter 1 reviews literature from three distinct areas, including delusions, autobiographical memory, and hypnosis. Chapter 1 reviews a model of the self and autobiographical memory proposed by Conway (2005) and outlines the value of using hypnosis instrumentally to model delusions of self. Chapter 2 presents two experiments that established hypnosis as a suitable paradigm for investigating identity delusions. These experiments examined the parameters of the hypnotic delusion and tested the impact of the delusion on self and autobiographical memory. Chapter 3 presents two experiments that continued to examine the characteristics of autobiographical memory during a hypnotic identity delusion. These experiments indexed the specificity, source, perspective, and qualitative features of autobiographical memories elicited during a suggested identity delusion. Chapter 4 presents two experiments that investigated memory processing during a hypnotic identity delusion. These experiments illustrated the shifting accessibility of autobiographical memories during a hypnotic identity delusion. Finally, Chapter 5 draws the empirical findings together to discuss the value of hypnosis as a technique for modelling identity delusions and the ways in which a hypnotic identity delusion influences autobiographical memory. Importantly, Chapter 5 proposes a model of deluded autobiographical memory that integrates Conway???s (2005) self-memory system with relevant aspects of Langdon and Coltheart???s (2000) two-factor theory of delusions. Using this proposed model as a framework, Chapter 5 discusses the clinical and theoretical implications of the findings from this thesis and suggests future research directions.

Purpose: A systematic review and meta-analysis was conducted to test key predictions of the widely-studied ‘paranoia as defence’ model (more formally known as the ‘attribution–self-representation cycle’) proposed by Bentall, Corcoran, Howard, Blackwood, and Kinderman (2001), as applied to people with psychosis with persecutory delusions. A novel case series was also conducted to examine the feasibility and acceptability of collaborative psychological assessment and formulation of impaired treatment decision-making capacity (TDMC) among patients with psychosis, and produce preliminary data on safety and efficacy. Methods: With regard to the systematic review and meta-analysis, people with psychosis with persecutory delusions were compared to healthy controls, people with depression and people with psychosis without persecutory delusions (and, if specified, grandiose delusions) on a number of outcomes: externalising attributional bias, explicit self-esteem, implicit self-esteem and discrepancy between implicit and explicit self-esteem. Correlations between paranoia severity and each of these outcomes and self-esteem instability were also examined. In regards to the case series, a formulation of impaired TDMC for 5 patient participants was developed and shared with 13 clinician participants. Acceptability, utility, working alliance and safety were assessed through pre and post self-report and interview measures. Results: Sixty-three studies were included in the meta-analysis and systematic review, of which 33, 36, 10, 10 and 4 were used to test hypotheses on externalising attributional bias, explicit self-esteem, implicit self-esteem, implicit-explicit self-esteem discrepancy and selfesteem instability, respectively. Key model-consistent findings included the following: people with psychosis with persecutory delusions had a greater externalising attributional bias compared to all the other groups and a greater implicit-explicit self-esteem discrepancy than people with depression, and paranoia severity was positively correlated with externalising attributional bias and self-esteem instability. Key model-inconsistent findings included the following: people with psychosis with persecutory delusions had lower explicit self-esteem than healthy controls, and paranoia severity was negatively correlated with explicit self-esteem. There were also some model-inconclusive findings. Regarding the case series, 3 of the patient participants collaborated in the development of their formulation. They found the intervention safe and acceptable, following which they provided a much richer understanding of the factors that may impair their TDMC (Cohen’s d = 2.16). Two patient participants only partially adhered to the intervention protocol, but a psychological formulation was still feasible to produce and no adverse effects were reported. Clinician participants provided a much richer understanding of the factors that may impair the patient participants’ TDMC (Cohen’s d = 1.36; 95% CI = 0.63 to 2.07) after the presentation of the case formulations. Increases in knowledge, confidence and positive attitudes regarding supporting the TDMC of patients were observed. They strongly believed that the formulations cohered with their knowledge of the patient participants and were comprehensive and accurate. Conclusions: The findings of the systematic review and meta-analysis support a ‘weak’ version of the paranoia as defence model, which suggests persecutory delusions are only partially effective at protecting low implicit self-esteem from reaching awareness. The findings of the case series suggest that patients with psychosis, and their clinicians, can be engaged in a collaborative psychological assessment and formulation of factors that may impair their TDMC. Initial data from the case series also suggests this process is acceptable, safe and helpful.

Background: Current psychological theories of persecutory delusions appear limited in being able to explain their interpersonal nature. Unanswered questions include why the content of delusions mostly involves persecution by other people. Research into rejection including rejection sensitivity may provide a rational for delusion personalisation and also may indicate how rejection may be implicated in the maintenance of delusions. The aim of this study was to investigate responses to rejection for individuals with a psychosis that includes persecutory delusions compared with controls. Methodology: Participants (22 with psychosis with persecutory delusions, 18 with an anxiety disorder and 19 healthy individuals) played a computerised game of catch (Cyberball). Half of each group was either included or excluded, inducing a mood change in those rejected. Questionnaires were completed to measure mood change, indicating rejection sensitivity. A second task was completed enabling participants to react either antisocially or neutrally towards the game characters. Measures of psychological and demographic variables were also collected. Results: There was a large effect between the excluded and included participants. There was a null finding for the hypothesis that the psychotic group would have higher levels of rejection sensitivity than the anxious and healthy groups. There was also a null finding for the hypothesis that the psychosis group will be more likely to respond antisocially after rejection and make more negative attributions about the game character’s personalities. However, there was a trend for a the psychotic group to be more antisocial after inclusion. Conclusions: The results obtained in the study were contrary to those expected. Rejection appears to be a similarly negative experience for all participants, but differences may be observed behavioural responses with those with psychosis appearing ambivalent to inclusion or exclusion.

A growing body of research demonstrates that paranoia is common in the general population. Four studies are presented that investigate factors associated with paranoia and naturalistic change in non-clinical groups. First, two experimental studies examine paranoia in the context of the Prisoner's Dilemma Game (PDG), an interpersonal research paradigm, where two players have the choice to cooperate or compete with each other. The dominant and rational choice for both players is to compete, however each players' individual reward would be greater if they both played cooperatively. Study 1 found that higher state paranoia was associated with the choice to compete. However the competitive choice can be selected due to distrust of the other player, or in order to maximise personal gain. The second experimental study employs a Three-Choice version of the PDG (PDG-Alt) that includes the option to withdraw, the rational choice when distrust of the other player is high. Higher state paranoia was associated with the withdrawal choice. These studies conclude that the withdrawal choice in the PDG –Alt provides a potential behavioral marker of state paranoia. Second, two studies examine naturalistic change in nonclinical paranoia. Idiosyncratic accounts of a single past paranoid experience are elicited and variations in dimensions known to be important in clinical paranoia are examined. Results show that levels of preoccupation, distress, impact on well being and conviction that harm was intentional significantly reduce over time. However the amount of time passed since the experience occurred is not significantly associated with level of change. Finally, in Study 4 a qualitative investigation is presented that identifies themes associated with change in nonclinical experiences of paranoia. The thesis concludes with a discussion of the theoretical, clinical and research implications of the findings.

No abstract available. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1993.

The purpose of this study is to examine whether a typology of narcissism can be identified through various statistical analyses, specifically cluster analysis. Furthermore, this study attempted to further delineate whether claims of a dual nature of narcissism are well founded and to examine the mental health implications of "positive illusions." Subjects were 251 college students at a large Midwest University. The mean age of the participants was 21 years. Self-report measures of narcissism, positive illusions, and mental health were administered in counterbalanced order. Data were analyzed using multivariate analysis and cluster analysis to examine the relationship between narcissism, positive illusions and mental health. A moderate amount of narcissism was positively related to mental health and adjustment. Furthermore, participants high and low in narcissism correlated with poorer mental health and adjustment. Positive illusions were related to mental health, except for in groups high in narcissism. Indeed, there appears to be an optimal level of illusions, which are beneficial for mental health. The relationship between narcissism and positive illusions should continue to be explored. / Department of Educational Psychology

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