Home›Psychiatry› Meta-analysis finds no atypical reliance on priors in schizophrenia-spectrum psychosis
Meta-analysis finds no atypical reliance on priors in schizophrenia-spectrum psychosisNew findings clarify how the brain processes information in people with schizophrenia
Psychological medicinePublished September 9, 2026Study authors: Miller-Silva Chantal, Illingworth Benjamin J G, Martey Kirsten, Mujirishvili Tamara, de Beer Francis…PubMed ↗DOI ↗Editorial oversight: Dr. Ji-eun Park, MD · Brain, Mind & Pain
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Key Takeaway
Interpret prior reliance as unlikely to be a general deficit in psychosis.
This meta-analysis examined whether adults with schizophrenia-spectrum psychosis show atypical reliance on priors on behavioral measures compared with healthy controls. The analysis included 904 individuals with schizophrenia-spectrum psychosis and 1,039 healthy controls.
The primary result showed no evidence for atypical reliance on priors in psychosis (Cohen's d = 0.03; 95% CI [-0.27, 0.34]; p = 0.818). Secondary analyses found no association with delusions (Cohen's d = -0.16; 95% CI [-0.51, 0.19]; p = 0.293; SZ = 183) or hallucinations (Cohen's d = 0.04; 95% CI [-0.28, 0.36]; p = 0.780; SZ = 370). A two-level hierarchical model did not reconcile conflicting results (F(1,32) = 0.1, p = 0.758).
The authors note that findings do not suggest that psychosis is associated with a generalized predictive processing deficit spanning multiple aspects of perception. Limitations were not reported, and safety outcomes were not reported.
These results challenge the hypothesis that atypical prior reliance is a general feature of psychosis, but the analysis is limited by the absence of reported limitations and the observational nature of the included measures.
How this fits prior evidence
This meta-analysis addresses a gap in prior coverage, which has focused on symptom severity, treatment barriers, weight management, adjunctive exercise, and metabolic markers in schizophrenia. It does not directly confirm or contrast with those findings, but it extends the evidence base by testing a specific cognitive mechanism (prior reliance) and finding no support for a generalized predictive processing deficit. The null result for delusions and hallucinations contrasts with the idea that these symptoms are driven by atypical priors.
Scientists wanted to know if people with schizophrenia have a hard time balancing what they already know with what they see in the moment. This is called a 'prior' in brain science. Some people thought that the brain's ability to weigh these two things might be broken in people with psychosis.
After looking at data from nearly 2,000 people, the researchers found no evidence that this specific process was broken. The study looked at many different types of information to see if the brain was struggling to make sense of the world. The results showed that the brain's way of handling these predictions was very similar to that of healthy people.
Additionally, the study looked at whether these brain processes were linked to specific symptoms like hearing voices or having false beliefs. They found no clear link between these specific brain patterns and those symptoms. This suggests that the condition is not caused by a single, broad problem in how the brain predicts the world around it.
What this means for you:
The study found no evidence that people with schizophrenia have a general problem with how their brains process information.
Common questions
Does this study change how schizophrenia is treated?
No, these findings do not suggest a change in current medical practices. The study found no evidence for a generalized predictive processing deficit in psychosis. Because the results do not show a specific link to hallucinations or delusions, the findings are used to understand brain processes rather than to change daily treatment plans.
What did the researchers find regarding hallucinations and delusions?
The study found no association between atypical reliance on priors and the presence of delusions or hallucinations. Specifically, the data showed no significant link for the 183 cases of delusions or the 370 cases of hallucinations reported in the analysis.
How many people were included in this study?
The meta-analysis included a large group of participants to ensure a broad look at the data. It included 904 individuals with schizophrenia-spectrum psychosis and 1,039 healthy controls to compare their behaviors and perceptions.
BACKGROUND: The influential predictive processing theory of psychosis posits that symptoms arise from an imbalanced weighting of predictions () and sensory evidence, yet studies present conflicting results. This is particularly problematic as findings from single tasks with modest sample sizes are frequently used to advance a theory for a generalized altered reliance on priors in psychosis.
METHODS: This study presents a random-effects, multi-level meta-analysis (PROSPERO CRD42024574379) evaluating evidence for aberrant reliance on priors in psychosis across perceptual tasks. The search identified articles in Embase, MEDLINE, APA PsycINFO, and APA PsycArticles published between 1st January 2005-31st October 2024, with risk of bias assessed using the Newcastle-Ottawa Scale. Included articles (34 results from 27 studies) compared adults with schizophrenia-spectrum psychosis (SZ; = 904) to healthy controls ( = 1,039) on behavioral measures representing reliance on priors.
RESULTS: Results provided no evidence for atypical reliance on priors in psychosis ( = .03, 95% CI [-0.27, 0.34]; = .818) or associations with delusions (6 results; SZ = 183; = -.16, 95% CI [-0.51, 0.19]; = .293) or hallucinations (10 results; SZ = 370; = .04, 95% CI [-0.28, 0.36]; = .780). In contrast with the theory that psychosis differentially affects priors at different levels of the cognitive hierarchy, a sub-group analysis indicated that a two-level hierarchical model of priors did not reconcile conflicting results ( (1,32) = 0.1, = .758).
CONCLUSIONS: These findings do not suggest that psychosis is associated with a generalized predictive processing deficit spanning multiple aspects of perception.
