The jumping to conclusions bias (JTC) is considered to be an important causal factor in theoretical models for the formation and maintenance of delusions. However, recent meta-analytic findings show a rather equivocal pattern of results regarding associations between JTC and delusions. Thus, the present study aims to investigate in a large sample whether the JTC-bias is more pronounced in patients with psychotic disorders in comparison to controls and whether the JTC bias is associated with a more severe delusional conviction, persecutory delusions, and positive symptoms in general. Patients with psychotic disorders (n = 300) enrolled in a therapy trial and healthy controls (n = 51) conducted a variant of the beads task (fish task) as a measure for the JTC-bias at the start of the trial. Further, clinical interviews were used to assess patients’ delusional severity and delusional conviction. There were no statistically significant differences between patients with psychotic disorders (with 53% displaying the JTC-bias) and controls (41%). Furthermore, there were no statistically significant correlations between JTC measures and persecutory delusions, delusional conviction, and positive symptoms. We found no differences in JTC between patients with psychotic disorders and healthy controls, which is in part in line with meta-analytic findings using a wide range of JTC task variants. Interestingly, patients with psychotic disorders displayed JTC rates commonly found in the literature, while healthy control subjects showed an unexpectedly high level of JTC. The task variant we used in the present study (fish task) is discussed as a potential reason for our results, as it may induce a more deliberative reasoning style in controls as compared to the traditional beads task. Furthermore, possible implications for the measurement of the JTC-bias, in general, are discussed. ISRCTN29242879 ( isrctn.com ), date of registration: April 12th 2006, retrospectively registered.

中文翻译：

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用鱼任务来测量精神病患者的JTC偏倚的问题：随机对照试验基线评估的二级分析

跳到结论偏差（JTC）被认为是理论模型中妄想形成和维持的重要因果因素。但是，最近的荟萃分析发现显示出关于JTC和妄想之间关联的结果的模棱两可。因此，本研究旨在调查一个较大的样本，与对照组相比，精神病患者的JTC偏见是否更为明显； JTC偏倚是否与更严重的妄想定罪，迫害性妄想和积极症状相关。一般。参加治疗试验的患有精神病的患者（n = 300），健康对照（n = 51）进行了一项变种的念珠任务（鱼任务），作为试验开始时对JTC偏见的一种衡量方法。进一步，临床访谈被用来评估患者的妄想严重程度和妄想信念。精神病患者（53％显示JTC偏见）与对照组（41％）之间无统计学差异。此外，JTC措施与迫害妄想，妄想定罪和阳性症状之间在统计学上无显着相关性。我们发现患有精神病的患者和健康对照者之间的JTC没有差异，这部分与使用多种JTC任务变体的荟萃分析结果一致。有趣的是，精神病患者表现出文献中常见的JTC发生率，而健康对照者表现出意想不到的高水平的JTC。我们在本研究中使用的任务变体（鱼类任务）被讨论为得出结果的潜在原因，因为与传统的珠子任务相比，它可能在控件中引发更多的商议性推理风格。此外，通常还讨论了对JTC偏差测量的可能含义。ISRCTN29242879（isrctn.com），注册日期：2006年4月12日，追溯注册。