Objective: The Cognitive Biases Questionnaire for psychosis (CBQp) was developed to capture 5 cognitive distortions (jumping to conclusions, intentionalising, catastrophising, emotional reasoning, and dichotomous thinking), which are considered important for the pathogenesis of psychosis. Vignettes were adapted from the Cognitive Style Test (CST), 1 relating to "Anomalous Perceptions" and "Threatening Events" themes. Method: Scale structure, reliability, and validity were investigated in a psychosis group, and CBQp scores were compared with those of depressed and healthy control samples. Results: The CBQp showed good internal consistency and test-retest reliability. The 5 biases were not independent, with a 2-related factor scale providing the best fit. This structure suggests that the CBQp assesses a general thinking bias rather than distinct cognitive errors, while Anomalous Perception and Threatening Events theme scores can be used separately. Total CBQp scores showed good convergent validity with the CST, but individual biases were not related to existing tasks purporting to assess similar reasoning biases. Psychotic and depressed populations scored higher than healthy controls, and symptomatic psychosis patients scored higher than their nonsymptomatic counterparts, with modest relationships between CBQp scores and symptom severity once emotional disorders were partialled out. Anomalous Perception theme and Intentionalising bias scores showed some specificity to psychosis. Conclusions: Overall, the CBQp has good psychometric properties, although it is likely that it measures a different construct to existing tasks, tentatively suggested to represent a bias of interpretation rather than reasoning, judgment or decision-making processes. It is a potentially useful tool in both research and clinical arenas.
Key words: schizophrenia/thinking errors/delusions/ hallucinations/cognitive behavior therapy for psychosis
IntroductionRecent biopsychosocial models of psychosis have emphasized the central role of cognitive factors, 2-5 both in terms of the content of appraisals 6,7 and the process of reasoning and metacognition. 8,9 Specifically, there is a large body of work demonstrating that cognitive biases play a key role in the formation and maintenance of delusions. 10 The strongest evidence base relates to the "jumping to conclusions" (JTC) 8 and attributional biases. 11 The JTC bias refers to the tendency to gather little information before making a decision, thereby increasing the likelihood of inaccurate beliefs being formed hastily. It is present in schizotypal, 12,13 at-risk, 14 symptomatic, 8 and remitted 15 psychotic populations and is stable over time. 16 Attributional biases have been investigated mainly in persecutory 17,18 and, to a lesser extent, in grandiose delusions. 19 Deluded participants make external attributions for negative events 20 and, more specifically, favor personalizing attributions, 21 whereby other people, rather than circumstances, are blamed for negative events. 6,7 While the researc...