Jumping to conclusions, general intelligence, and psychosis liability: findings from the multi-centre EU-GEI case-control study

Abstract

Background The ‘jumping to conclusions’ (JTC) bias is associated with both psychosis and general cognition but their relationship is unclear. In this study, we set out to clarify the relationship between the JTC bias, IQ, psychosis and polygenic liability to schizophrenia and IQ. Methods A total of 817 first episode psychosis patients and 1294 population-based controls completed assessments of general intelligence (IQ), and JTC, and provided blood or saliva samples from which we extracted DNA and computed polygenic risk scores for IQ and schizophrenia. Results The estimated proportion of the total effect of case/control differences on JTC mediated by IQ was 79%. Schizophrenia polygenic risk score was non-significantly associated with a higher number of beads drawn (B = 0.47, 95% CI −0.21 to 1.16, p = 0.17); whereas IQ PRS (B = 0.51, 95% CI 0.25–0.76, p < 0.001) significantly predicted the number of beads drawn, and was thus associated with reduced JTC bias. The JTC was more strongly associated with the higher level of psychotic-like experiences (PLEs) in controls, including after controlling for IQ (B = −1.7, 95% CI −2.8 to −0.5, p = 0.006), but did not relate to delusions in patients. Conclusions Our findings suggest that the JTC reasoning bias in psychosis might not be a specific cognitive deficit but rather a manifestation or consequence, of general cognitive impairment. Whereas, in the general population, the JTC bias is related to PLEs, independent of IQ. The work has the potential to inform interventions targeting cognitive biases in early psychosis.

Increased Belief Instability in Psychotic Disorders Predicts Treatment Response to Metacognitive Training

“…A striking aspect of our results is that despite evident relationships between psychotic disorders and both behavioral and computational measures—and the potential for computational parameters to predict treatment outcome—we did not find any relationship between these measures and current delusions, even though these tasks were designed to assess reasoning biases thought to contribute to delusions themselves. Our findings add to a growing literature including meta-analyses, 53 large case-control, 54 and population-based studies 55 that find weak or absent correlations between delusion and beads task measures.…”

Problems in measuring the JTC-bias in patients with psychotic disorders with the fish task: A secondary analysis of a baseline assessment of a randomized controlled trial

“…Furthermore, as misunderstandings of the instructions of the beads task occur more often in patients with psychosis than in healthy controls [10], they could also contribute and enlarge the frequently found group differences between patients and healthy controls. This interpretation is supported by the ndings of a large study by Tripoli et al [48], who found that the association between JTC and psychotic symptoms in patients with psychosis seems to be mediated to a large extent by IQ of the subjects. Therefore, JTC may be a consequence of more basic cognitive de cits, which may contribute to a misunderstanding of the task.…”

Problems in measuring the JTC-bias in patients with psychotic disorders with the fish task: A secondary analysis of a baseline assessment of a randomized controlled trial

“…Furthermore, as misunderstandings of the instructions of the beads task occur more often in patients with psychosis than in healthy controls [10], they could also contribute and enlarge the frequently found group differences between patients and healthy controls. This interpretation is supported by the ndings of a large study by Tripoli et al [48], which found that the association between JTC and psychotic symptoms in patients with psychosis seems to be mediated to a large extent by the IQ of the subjects. Therefore, JTC may be a consequence of more basal cognitive de cits, which may contribute to a misunderstanding of the task.…”