On the fixed nature of delusions
George E. Chapman, Philip R. Corlett, Stephen M. Fleming, Robert J. Howard
Nature Mental Health June 1, 2026 Peer reviewed DOI: 10.1038/s44220-026-00647-z via Springer Nature
Summary
Delusions are fixed false beliefs characteristic of psychotic disorders, but why they remain so rigidly held is not well understood. This review proposes a clearer vocabulary for delusion fixity, breaking it into conviction, incorrigibility, persistence, and stability. It examines factors from diagnosis, psychopathology, psychodynamics, social context, cognition, metacognition, and cognitive neuroscience that influence fixity, and integrates these into a working model. The authors call for interdisciplinary longitudinal studies to better understand delusion fixity and develop improved therapies.
Study at a glance
| Design | review |
|---|---|
| Key finding | Delusion fixity can be understood through the dimensions of conviction, incorrigibility, persistence, and stability, influenced by multiple psychological and neurobiological factors. |
Abstract
Delusions are a key feature of psychotic disorders, yet their fixity remains underexplored. Here, the authors propose a refined vocabulary for delusion fixity, review influencing factors, and present a working model. The Review calls for interdisciplinary longitudinal studies that could enhance the understanding of delusion fixity and facilitate the advancement of therapeutic strategies. Fixed, false beliefs—known as delusions—are a hallmark of psychotic illness. While considerable research has explored the emergence of delusions, relatively little has focused on their fixity. Here we recap classical and contemporary descriptions of delusions and highlight some outstanding issues besides fixity. We then examine the definition and measurement of belief fixity to date and propose a clearer vocabulary for the fixity of delusions in particular, in terms of their conviction, incorrigibility, persistence and stability. Using these terms, we review the extent to which delusions may truly be considered fixed and the diagnostic, psychopathological, psychodynamic, social, cognitive, metacognitive and cognitive neuroscience factors influencing this. We then integrate this evidence in a working model of delusion fixity. Finally, we summarize limitations of the existing literature and highlight opportunities for future research. We predict that longitudinal within-patient studies, which work across specialisms and perspectives, will be particularly valuable for furthering an integrated understanding of delusion fixity.