Delusions and hallucinations in first-episode psychosis patients: A systematic review on the influence of metacognition.

Abstract

First-episode psychosis (FEP), primarily characterized by positive symptoms such as delusions and hallucinations, can be perceived as an embedding failure of metacognition. Metacognition refers to the ability to monitor, control, and regulate one's own cognitive processes, from subtle mechanisms to more integrative functions essential for daily life. Impairments in metacognition are observed across various psychiatric conditions and can be assessed directly (through metacognitive ability itself) or indirectly (by probing clinical insight, cognitive insight, and cognitive biases). Dysfunctions in metacognitive processes are believed to be related to the onset and persistence of psychotic symptoms, potentially affecting individuals even in the prodromal stages of psychotic disorders. Targeted metacognitive therapy (MCT) for these individuals has demonstrated promising effects in reducing symptoms. However, the relationship between metacognition and positive symptoms is not yet clear, as a cause or consequence, posing an epistemological question. This review aims to synthesize relevant data on the role of metacognition in delusions and hallucinations, with a particular focus on its association with the onset and personal experience of first-episode hallucinations and delusions. The search was conducted using PubMed, Scopus and Web of Science between October 2024 and February 2025. Forty-one articles were included for review, comprising cohort, case-control and cross-sectional studies. Overall, we identified a complex relationship between several constructs of metacognition and positive symptoms. The most compelling evidence arises from studies on cognitive biases, with 70% reporting significant associations with positive symptoms, and on MCT interventions, with 86% of studies in FEP reporting significant improvements in positive symptoms.