نیاز برای بسته شدن و اضطراب در هذیان ها: مطالعه طولی در روان پریشی اولیه

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.

There is some evidence that need for closure (NFC) might be involved in the cognitive processes and reasoning of people with delusional beliefs (Bentall & Swarbrick, 2003; Colbert & Peters, 2002). NFC is the desire for an answer, any answer, rather than confusion and ambiguity (Kruglanski, 1990). People high in NFC “may ‘leap’ to judgement on the basis of inconclusive evidence and exhibit rigidity of thought and reluctance to entertain views different from their own” (Kruglanski & Webster, 1996, p. 264). Colbert and Peters (2002) found that healthy individuals high in delusional ideation scored significantly higher on the NFC Scale (NFCS; Kruglanski, Webster, & Klem, 1993) relative to those low in delusional ideation. Bentall and Swarbrick (2003) investigated NFC, using the same scale, in a group of acutely ill psychotic patients with persecutory delusions, a group whose persecutory delusions had remitted and a non-clinical control group. They found that both the clinical groups scored significantly higher on NFC than the control group, and did not differ from each other. These differences could not be accounted for by depressive symptoms. However, neither of the above studies addressed the possibility that anxiety is related to NFC. People high in NFC may experience ambiguity, uncertainty and confusion as anxiety provoking. This anxiety increases their motivation for closure, and coming to a decision removes uncertainty, thus reducing their anxiety. Evidence consistent with the hypothesis that NFC is related to anxiety comes from Neuberg and colleagues. This study compared scores on the Personal Need for Structure (PNS) Scale (Neuberg & Newsome, 1993) with the social anxiety sub-scale of the Self-Consciousness Scale (Fenigstein, Scheier, & Buss, 1975) and the Taylor Manifest Anxiety Scale (Taylor, 1956). The PNS is similar to the NFCS and was designed to measure the extent to which people structure their worlds in a simple manner. Significant correlations were found between the PNS and both measures of anxiety. Showers (2002, pers. comm.) also found a significant correlation between the Spielberger State–Trait Anxiety Inventory (Spielberger, Gorsuch, Lushene, Vagg, & Jacobs, 1983) and the PNS. The concept of intolerance of uncertainty (IU), introduced by Freeston and colleagues, is also similar to NFC. They claim that IU causes anxiety by leading a person to worry over the uncertainty of future events (Dugas, Gagnon, Ladouceur, & Freeston, 1998), and indeed IU has been found to be closely related to worry (Dugas, Freeston, & Ladouceur, 1997). This finding lends further credence to the hypothesis that NFC may be related to anxiety. Interestingly, Maher (1974) has suggested that delusions are maintained by the reduction in anxiety produced by the availability of an explanation for psychotic perceptual anomalies. Freeman, Garety, Kuipers, Fowler, and Bebbington's (2002) model also highlights the important role anxiety plays in the formation and maintenance of persecutory delusional beliefs. This model proposes that NFC may be one of the factors involved in individuals forming a delusional belief. However, it remains unclear whether there is a direct link between NFC and delusions, or whether the relationship is indirect and occurs through the association of NFC with anxiety. The primary aim of this study was to explore the link between anxiety and NFC in delusion formation. The investigation of these factors in a group who have only recently become psychotic allows the disentanglement of putative psychotic processes from factors that develop with chronicity of illness, e.g. history of medication, relapses and residual symptoms. A deluded group, early in the course of psychosis, was therefore compared to an anxious group (individuals diagnosed with generalised anxiety disorder—GAD) and a non-clinical control group, on NFC and anxiety measures. The GAD group was chosen to control for the presence of anxiety. It was hypothesised that the deluded and GAD groups would score higher on the NFCS, and that NFCS scores would be related to anxiety. The unidimensionality of the NFCS was not assumed and each sub-scale was analysed separately. The NFCS consists of five sub-scales: preference for order, discomfort with ambiguity, preference for predictability, decisiveness and close-mindedness. Kruglanski et al. (1997) have proposed that the scores on each of these sub-scales can be summed to give a total score that is a measure of an individual's overall NFC. However, Neuberg, Judice, and West (1997) have suggested that the scale is not unidimensional, since the five sub-scales are not all positively correlated with each other. They found that while the preference for order, preference for predictability and discomfort with ambiguity sub-scales were all highly related, the close-mindedness sub-scale had lower correlations, and the decisiveness sub-scale had negative correlations, with some of the other sub-scales. They argue that the total score cannot be used, as this would mask the complex, and sometimes even inverse, relationships between the different sub-scales. A further aim of this study was to follow-up the participants approximately a year later. The recovery of only a sub-set of participants was anticipated, allowing the comparison of recovered and non-recovered groups at follow-up on the NFCS and anxiety measures. A longitudinal design was employed to investigate whether NFC is a factor which may contribute to the formation of delusions, rather than a cognitive bias which is active merely in the presence of delusions and is only involved in their maintenance. The longitudinal design provided the opportunity to determine whether (1) there is a direct link between NFC and anxiety, which would predict a reduction in both NFC and anxiety at follow-up, or whether (2) NFC is a stable factor related to delusion formation, independent of anxiety, which would predict high NFCS scores in the deluded group despite a reduction in anxiety scores.