which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. Cognitive Mechanisms of Change in Delusions: An Experimental Investigation Targeting Reasoning to Effect Change in Paranoia

Background: Given the evidence that reasoning biases contribute to delusional persistence and change, several research groups have made systematic efforts to modify them. The current experiment tested the hypothesis that targeting reasoning biases would result in change in delu-sions. Methods: One hundred and one participants with current delusions and schizophrenia spectrum psychosis were randomly allocated to a brief computerized reason-ing training intervention or to a control condition involving computer-based activities of similar duration. The pri-mary hypotheses tested were that the reasoning training intervention, would improve (1) data gathering and belief flexibility and (2) delusional thinking, specifically para-noia. We then tested whether the changes in paranoia were mediated by changes in data gathering and flexibility, an