Cognitive functioning in delusions: a longitudinal analysis

BACKGROUND: This study explored the longitudinal course of the relationship between delusions and different aspects of cognitive functioning. METHODS: Deluded patients were compared to psychiatric and non-clinical controls on three tasks: negative priming, a probabilistic judgement task (the 'beads' task), and the pragmatic inference task (PIT). All groups were tested at two time points, once when actively symptomatic, and once when in remission. RESULTS: Deluded individuals exhibited a 'jump-to-conclusions' (JTC) reasoning bias: i.e., they made decisions on the basis of limited evidence and were more likely to revise their estimates when faced with disconfirmatory evidence. This JTC bias remained stable over time, although probability judgments seemed to normalise in remission. No deficits in cognitive inhibition were found on negative priming. The deluded group displayed an excessive self-focus on the PIT at both time points, but did not show a depressive attributional style. Only a small sub-sample, characterised by the "bad-me" type of paranoia [Trower & Chadwick, 1995 Clinical Psychology: Science and Practice, 2, 263-278.], demonstrated depressive schemas when symptomatic, but no longer did so when remitted. Few relationships were found between tasks, suggesting that different areas of functioning are relatively independent. The only measures associated with delusion symptom scores were from the 'beads' task. CONCLUSIONS: Overall these findings suggest that the JTC bias is a stable factor associated with delusional thinking, while the depressive attributional style characteristic of a small sub-sample of paranoid patients fluctuates with delusional course.     

Delusions and decision-making style: use of the Need for Closure Scale

Clinicians and researchers have suggested that rapidity in belief formation, due to having a high 'need for closure' (NFC), may contribute to the acceptance of delusional explanations. The aim of the study is to determine whether NFC has such a direct link with delusions. A secondary aim is to examine if NFC is related to the delusion-associated reasoning process of 'jumping to conclusions'. One hundred and eighty-seven patients with psychosis, recruited for a treatment trial of psychological therapy (the PRP trial), completed the Need for Closure Scale (NFCS), symptom measures, and probabilistic reasoning tasks. The NFCS was considered in terms of its two dimensions: a desire for simple structure and a preference for quick, decisive answers. The individuals with psychosis reported being poor at making quick, decisive answers but required a greater need for simple structure. NFC was associated with levels of anxiety and depression. There were weak links between NFC and both positive and negative symptoms of psychosis, but these were explained by differences in affect. NFCS scores were unrelated to jumping to conclusions. Contrary to the argument that NFC is directly linked to delusions, individuals with delusions actually perceive themselves as indecisive. There was no evidence that NFC-at least as assessed by the NFCS-could be a proximal cause of delusions. Any potential effect on psychotic symptom presentation is indirect, mediated through affect. The use of the NFCS on its own in the study of psychotic symptoms cannot be recommended.     

Need for closure and anxiety in delusions: a longitudinal investigation in early psychosis

This study investigated the role of need for closure (NFC) and anxiety in delusions. The Need For Closure Scale (NFCS) and measures of trait and state anxiety were administered to an early psychosis group with current delusions, a clinical (generalised anxiety disorder--GAD) control group and a non-clinical control group. The battery of questionnaires was repeated at follow-up one year later. The NFCS did not meet criteria for a unidimensional scale and two sub-scales were removed from all further analyses. At baseline the deluded and GAD groups scored significantly higher on the reduced NFCS (NFCS-R) than the control group. Trait anxiety was related to NFCS-R in the GAD and non-clinical control groups, but not in the deluded group. At follow-up all groups scored significantly lower on the NFCS-R, perhaps suggesting a practice effect, although the two clinical groups continued to have higher scores than the non-clinical control group. The recovered and non-recovered deluded groups did not differ on the NFCS-R one year later, unlike in the GAD group where recovered participants had significantly lower scores than the non-recovered. Change scores on the NFCS-R and trait anxiety were correlated at trend level in the GAD and non-clinical control groups, but not in the deluded group. These findings suggest that whilst NFC and trait anxiety are related in non-psychotic groups, NFC may be implicated in the formation of delusions, independently of anxiety, in psychotic individuals.     

Probabilistic judgements in deluded and non-deluded subjects

An experiment is described in which deluded subjects were compared with a non-deluded psychiatric control group and a normal control group on a probabilistic inference task. Deluded subjects were found to request less information before reaching a decision and to express higher certainty levels than either control group. They also exhibited over-confidence on estimates of the probability of a future event.

Delusion. A false personal belief based on incorrect inference about external reality and firmly sustained in spite of what almost everyone else believes and in spite of what constitutes incontrovertible and obvious proof or evidence to the contrary. The belief is not one ordinarily accepted by other members of the person's subculture. [American Psychiatric Association, 1980]     

The just world hypothesis as an argumentative resource in debates about unemployment benefits

The concept of the “just world” is established as a key explanation for how people make sense of inequality so that those deemed to score high in belief in a just world are more likely to hold prejudicial beliefs and to blame people in poverty for their situations. However, this is an inadequate explanation for such complicated and controversial issues. To better understand talk about the just world and the controversial issue of the distribution of unemployment benefits (an issue of inequality), a discursive psychological approach to the just world is used. Therefore, a discourse analysis focusses on 2 feature length British televised discussions about benefit claimants called “The Big Benefit Row: Live” (Channel 5 3/2/2014) and “Benefits Britain: the Debate” (Channel 4 17/2/2014). The analysis demonstrates that people draw on both just and unjust world arguments simultaneously and also topicalise what counts as just so as to support their positions on unemployment benefits, rather than in the consistent way that just world theory would predict. It is therefore argued that the just world should be recast as a cultural value that facilitates arguments about benefits, rather than an internally held belief.     

A factorization procedure for finite algebras

A procedure is developed for decomposing any finite algebra into a minimal set of maximally independent simple homomorphic images, or factors, of the algebra. The definition of admissible sets of factors is made in relation to the congruence lattice of the algebra, and generalises the notion of an irredundant reduction in a modular lattice. An algorithm for determining all possible sets of factors of a given finite algebra is derived and an index for measuring the degree of independence of factors is defined. Applications of the technique to finite algebraic models within the social psychological domain are presented and include factorizations for certain semigroups of binary relations and for a class of finite semilattices.     

Intrusive memories and depression in cancer patients

Matched samples of depressed and nondepressed cancer patients were interviewed about past life events, particularly experiences of death and illness. They identified and described any spontaneous intrusive visual memories they had experienced in the past week corresponding to these events. About one quarter reported such memories and, as predicted, the majority of intrusive memories concerned illness, injury and death. The mean levels of intrusion and avoidance were equivalent to patients with post-traumatic stress disorder. Consistent with prediction, depressed patients reported significantly more intrusive memories than controls, and described the memories as typically beginning with or being exacerbated by the onset of depression. Greater numbers of intrusive memories were associated with more maladaptive coping, and greater avoidance with deficits in autobiographical memory functioning.