Cognitive Mechanisms of Change in Delusions: An Experimental Investigation Targeting Reasoning to Effect Change in Paranoia

Abstract

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 delusions. Methods: One hundred and one participants with current delusions and schizophrenia spectrum psychosis were randomly allocated to a brief computerized reasoning training intervention or to a control condition involving computer-based activities of similar duration. The primary hypotheses tested were that the reasoning training intervention, would improve (1) data gathering and belief flexibility and (2) delusional thinking, specifically paranoia. We then tested whether the changes in paranoia were mediated by changes in data gathering and flexibility, and whether working memory and negative symptoms moderated any intervention effects. Results: On an intention-to-treat analysis, there were significant improvements in state paranoia and reasoning in the experimental compared with the control condition. There was evidence that changes in reasoning mediated changes in paranoia, although this effect fell just outside the conventional level of significance after adjustment for baseline confounders. Working memory and negative symptoms significantly moderated the effects of the intervention on reasoning. Conclusion: The study demonstrated the effectiveness of a brief reasoning intervention in improving both reasoning processes and paranoia. It thereby provides proof-of-concept evidence that reasoning is a promising intermediary target in interventions to ameliorate delusions, and thus supports the value of developing this approach as a longer therapeutic intervention.

Individualized metacognitive therapy for delusions: A randomized controlled rater-blind study

“…Hence, most patients would have had at least some superficial contact with the concept of "hasty decisions", which may have biased findings. This is only a tentative explanation, since Garety et al (2015) noted a significant effect of their own individualized metacognitive intervention on the number of draws to decision despite a similarly high baseline value as in the present study. In any event, MCT+ did have beneficial effects on other indices of cognitive bias (decision threshold and BCIS self-reflectiveness).…”

“…However, there is still an ongoing debate about its efficacy, (McKenna and Kingdon, 2014) especially when it comes to disentangling 'true' efficacy from unspecific therapy effects (Jauhar et al, 2014;Lynch et al, 2010;Mehl et al, 2015). In an effort to maximize efficacy, recent research has focused on targeted therapies that deal with individual factors thought to contribute to psychotic symptoms, such as worry or reasoning biases (Garety et al, 2015;Moritz et al, 2014a;Waller et al, 2011). It has been suggested that such theory-driven interventions may lead to improved outcomes compared to standard CBT (Mehl et al, 2015).…”

“…However, the group intervention format may not be suited for some patients, including those with high level of suspiciousness (van Oosterhout et al, 2014), or patients with negative and/or disorganized symptoms that may require more intensive and structured work (Moritz et al, 2005). On the other hand, it has been suggested that the effects of metacognitive interventions on reasoning and delusions might be promoted with use of personalized material and individual therapy sessions (Garety et al, 2015;van Oosterhout et al, 2014).…”

Variation in psychosocial influences according to the dimensions and content of children’s unusual experiences: potential routes for the development of targeted interventions

“…These theoretical advances have informed the development of targeted CBTp interventions that focus on changing a particular cognitive or emotional process, in the context of a particular symptom presentation. Larger effect sizes for change in primary outcomes are typically reported in trials of targeted interventions, compared to those for trials of generic, undifferentiated CBTp protocols with heterogeneous therapy foci [23][24][25][26][27].…”

“…These theoretical advances have informed the development of targeted CBTp interventions that focus on changing a particular cognitive or emotional process, in the context of a particular symptom presentation. Larger effect sizes for change in primary outcomes are typically reported in trials of targeted interventions, compared to those for trials of generic, undifferentiated CBTp protocols with heterogeneous therapy foci [23][24][25][26][27].In recent studies, the psychosocial factors implicated in the onset, severity, and maintenance of adult psychosis have been found to also predict the occurrence and severity of childhood UEs [28][29][30][31][32][33][34]. Our research has shown that cognitive, emotional and social factors each make independent contributions to overall UE severity, supporting the general applicability of CBTp to this group [30].…”