Sleep and circadian disruption as transdiagnostic drivers of psychosis: a unified mechanistic framework.
INTRODUCTION Psychosis is increasingly understood as a disorder of brain systems that are also central to sleep regulation. Indeed, sleep disturbances are both highly prevalent in psychotic disorders and are likely to contribute to the emergence and maintenance of psychotic experiences. AREAS COVERED This narrative review, based on a comprehensive search of MEDLINE/PubMed, Embase, PsycINFO, and Web of Science (March 2026), examines the bidirectional relationship between sleep dysfunction and psychosis, the shared biological mechanisms underlying both, the utility of sleep assessment as an early warning marker for relapse, and the current gaps in sleep-targeted intervention evidence. EXPERT OPINION Sleep dysfunction constitutes a transdiagnostic pathway to psychosis, with varying temporal profiles across diagnoses: organic and substance-induced psychoses emerge acutely over hours to days with rapid reversibility; mood- and trauma-related psychoses develop subacutely over days to weeks; schizophrenia spectrum disorders show insidious onset over years with chronic persistence. Across these presentations, disturbances in sleep continuity, architecture, and circadian regulation may act as mechanistic drivers rather than epiphenomena, interacting with disorder-specific vulnerabilities to shape the timing, severity, and course of psychosis. Translating this understanding into practice requires routine sleep-circadian assessment from the earliest clinical stages, integration of scalable interventions into transdiagnostic care pathways, and recognition of sleep as both a clinically relevant outcome and a stratification variable in future psychosis trials. This framework positions sleep-circadian dysfunction not only as a marker of risk and progression, but also as a promising modifiable target for prevention, early intervention, and relapse reduction across psychotic disorders.