Reference: McLean, B. F.; Mattiske, J. K.; & Balzan, R. P. (2017). Association of the Jumping to Conclusions and Evidence Integration Biases With Delusions in Psychosis: A Detailed Meta-analysis. Schizophrenia Bulletin, 43(2), 344-354. https://doi.org/10.1093/schbul/sbw056

Can persons with schizophrenia have certain ways of thinking that likely maintain their delusions? 

Australian psychologists wanted to know the relationship between delusions and 4 cognitive biases: 
1. Jumping to conclusions, with inadequate evidence
2. Ignoring evidence that contradicts one’s beliefs
3. Not strongly considering true interpretations even though there is greater supporting evidence.
4. Believing evidence supportive of one’s (delusional) beliefs too easily. 

A meta-analysis of 35 studies examined these biases comparing persons with and without delusions.

Results? People with schizophrenia who experience delusions had stronger cognitive biases than people with schizophrenia without delusions. These cognitive biases were strongest during the acute phases of delusional thinking. A similar pattern appeared in people with other psychiatric conditions who had delusions, but not in those without delusions. This suggests these thinking biases are tied to delusions themselves, not just cognitive biases in and of themselves.

These thinking patterns may contribute to maintaining delusions. If cognitive biases fuel delusions, can therapy help persons with delusions identify and challenge their cognitive biases, to counter their delusions? Targeting these biases may be the key to better cognitive behavioral therapy—and clearer minds.

Written by Kristin M. Harris, Ph.D.