Differences in Cognitive and Emotional Processes Between Persecutory and Grandiose Delusions

Schizophrenia Bulletin vol. 39 no. 3 pp. 629–639, 2013 Schizophrenia Bulletin doi:10.1093/schbul/sbs059 doi:10.1093/schbul/sbs059 Advance Access publication April 12, 2012 Differences in Cognitive and Emotional Processes Between Persecutory and Grandiose Delusions 1 Department of Psychology, Institute of Psychiatry, King’s College London, PO77, Henry Wellcome Building, De Crespigny Park, London SE5 8AF, UK; 2Biostatistics Group, Health Sciences Research Group, School of Community-Based Medicine, University of Manchester, Manchester, UK; 3Department of Mental Health Sciences, Royal Free and University College Medical School, University College London, London, UK; 4Norwich Medical School, School of Medicine, Health Policy and Practice, University of East Anglia, Norwich, UK; 5 Department of Psychiatry, University of Oxford, Oxford, UK *To whom correspondence should be addressed; tel: 44-20-7848-5046, fax: 44-20-7848-5006, e-mail: Background: Cognitive models propose that cognitive and emotional processes, in the context of anomalies of experience, lead to and maintain delusions. No large-scale studies have investigated whether persecutory and grandiose delusions reflect differing contributions of reasoning and affective processes. This is complicated by their frequent cooccurrence in schizophrenia. We hypothesized that persecutory and grandiose subtypes would differ significantly in their associations with psychological processes. Methods: Participants were the 301 patients from the Psychological Prevention of Relapse in Psychosis Trial (ISRCTN83557988). Persecutory delusions were present in 192 participants, and grandiose delusions were present in 97, while 58 were rated as having delusions both of persecution and grandiosity. Measures of emotional and reasoning processes, at baseline only, were employed. Results: A bivariate response model was used. Negative self-evaluations and depression and anxiety predicted a significantly increased chance of persecutory delusions whereas grandiose delusions were predicted by less negative self-evaluations and lower anxiety and depression, along with higher positive self and positive other evaluations. Reasoning biases were common in the whole group and in categorically defined subgroups with only persecutory delusions and only grandiose delusions; however, jumping to conclusions, and belief flexibility were significantly different in the 2 groups, the grandiose group having a higher likelihood of showing a reasoning bias than the persecutory group. Conclusion: The significant differences in the processes associated with these 2 delusion subtypes have implications for etiology and for the development of targeted treatment strategies. Introduction It is increasingly recognized that psychosis is complex and multifactorial in origin, resulting from a number of interacting biological, psychological, and social factors.1 Recent cognitive models of positive psychotic symptoms accept the importance of biological processes but emphasize the contribution of psychological mechanisms, involving emotional and reasoning processes, to the development and persistence of psychosis.1–4 However, delusions vary in content, and different types of delusions may reflect distinct psychological processes. Factor analyses of delusions separate persecutory delusions from grandiose delusions, eg, refs.,5,6 and there is evidence of distinct correlates.7 Persecutory delusions are the most common type of delusion in schizophrenia, affecting about 80%,8 and receive the most theoretical and empirical attention, eg, refs.4,8 However, grandiose delusions are also common in schizophrenia, present in perhaps 25%–50% of people with the diagnosis.9 These 2 delusional subtypes should therefore cooccur in people with a diagnosis of schizophrenia spectrum psychosis, and only 10%–16% experience grandiose delusions in isolation.9 Such cooccurrence makes it difficult to disentangle individual effects,10 and this may result in processes associated with one type of delusion being incorrectly attributed to another. As predicted by cognitive models, changes in affect and reasoning are linked to paranoia. Thus paranoia is associated with negative emotional states and negative cognitions (low self-esteem, self-critical thinking, and extreme negative beliefs about self and others, eg,4,8,11). There is also evidence that disturbed reasoning, in particular the data gathering bias, ‘‘jumping to conclusions’’ (JTC), is associated with paranoia and with persecutory delusions.4,8,12–14 ‘‘Belief flexibility’’ is a reasoning process Key words: psychosis/reasoning/jumping to conclusions/ belief flexibility/affect/schemas © University Press on on behalf of of thethe Maryland Psychiatric Research Center.  The TheAuthors Authors2012. 2012.Published PublishedbybyOxford Oxford University Press behalf Maryland Psychiatric Research Center. This an Open Open Access Access article articledistributed distributedunder underthe theterms termsofofthe theCreative CreativeCommons CommonsAttributionNon-Commercial License(http://creativecommons.org/licenses/ (http://creativecommons.org/licenses/ This is is an Attribution Non-Commercial License by-nc/3.0), cited. by-nc/3.0), which which permits permits unrestricted unrestricted non-commercial non-commercialuse, use,distribution, distribution,and andreproduction reproductionininany anymedium, medium,provided providedthe theoriginal originalwork workis isproperly properly cited. 629 1 Philippa A. Garety1,*, Matthew Gittins2, Suzanne Jolley1, Paul Bebbington3, Graham Dunn2, Elizabeth Kuipers1, David Fowler4, and Daniel Freeman5 P. P.A. A.Garety Garetyetetal. al. The Current Study The present study reports the first test of hypotheses about reasoning and emotional processes in relation to persecutory and grandiose delusions. It is based on a large sample of people with a diagnosis of schizophrenia spectrum disorder, the 301 participants in the Psychological Prevention of Relapse in Psychosis (PRP) trial (ISRCTN 83557988).27 As persecutory and grandiose delusions commonly cooccur, we used a method of analysis (bivariate 2 630 logistic regression) capable of tackling this cooccurrence. Our previous research in this area was restricted to the separate examination of aspects of reasoning and emotional processes and, with one exception,11 was based on a much smaller sample, the first 100 participants in the trial.14,16,22,25,28 The analyses presented here were designed before the collection of data in the knowledge that they would require the whole dataset to provide the necessary statistical power. 1. We hypothesized that persecutory and grandiose delusions will significantly differ in their associations with emotional states (depression and anxiety) and with self-esteem and evaluations of self and others; specifically, paranoid delusions would be associated with depression and negative self-schemas, whereas grandiose delusions would be associated (...truncated)