Sleep Variability May Mark Psychosis Spectrum Differences
Wrist-worn sleep data may help researchers identify distinct sleep patterns in people at risk for psychosis and those with schizophrenia-spectrum disorders
A systematic review and meta-analysis found that people at clinical high risk for psychosis and those with schizophrenia-spectrum disorders had much wider person-to-person differences in sleep efficiency, time in bed, and nighttime wakefulness than healthy participants. The findings suggest that sleep variability may become a useful digital biomarker for more personalized psychiatric care, although it is not yet suitable for diagnosis or predicting who will develop psychosis.
Study Details
Sleep disturbances are common across the psychosis spectrum. They affect up to 70% of people considered at clinical high risk for psychosis and approximately 80% of people with schizophrenia-spectrum disorders. Most previous studies have focused on average sleep duration or average sleep quality. That approach can hide clinically important differences.
For example, a group containing both very short sleepers and very long sleepers may have a normal average sleep duration. The average looks healthy even though many individuals have substantially abnormal sleep patterns.
Researchers therefore examined whether people across the psychosis spectrum showed greater variation in sleep patterns than healthy participants.
Methodology
Researchers conducted a systematic review and meta-analysis of case-control studies that measured sleep using wrist actigraphy.
Actigraphy devices estimate sleep and wake patterns by continuously recording movement. They are less detailed than formal overnight sleep studies, but they allow researchers to observe sleep in everyday settings over several nights.
The analysis included 18 studies and 1,358 participants:
202 people at clinical high risk for psychosis
574 people with schizophrenia-spectrum disorders
582 healthy control participants
The researchers examined variability in total sleep time, time in bed, wakefulness after falling asleep, sleep efficiency, sleep latency, and number of awakenings. Rather than looking only at averages, they compared how widely sleep measurements differed among people within each group.
Key Findings
People at clinical high risk for psychosis had greater variability in time in bed, wakefulness after sleep onset, and sleep efficiency than healthy participants.
People with schizophrenia-spectrum disorders had greater variability in total sleep time, time in bed, wakefulness after sleep onset, and sleep efficiency.
Greater variability in total sleep duration was found only in people with established schizophrenia-spectrum disorders.
Sleep latency and the number of nighttime awakenings did not show significant variability differences.
Some average sleep measurements appeared similar between groups even when the underlying sleep patterns differed substantially from person to person.
Why Sleep Variability Matters
The study suggests that sleep problems in psychosis may not follow a single pattern.
Some patients may sleep very little. Others may sleep excessively. Some may spend long periods in bed without sleeping efficiently, while others may experience fragmented or inconsistent sleep.
These different patterns may be clinically important because they could reflect different biological mechanisms, medication effects, illness stages, or treatment needs.
A patient with severe insomnia may need a different intervention from someone experiencing excessive sleep or prolonged time in bed.
This supports a more personalized approach to sleep assessment in psychiatric care.
What the Findings Mean for Patients
The findings do not mean that irregular sleep is evidence of psychosis.
Sleep can be disrupted by stress, depression, anxiety, pain, medications, substance use, sleep apnea, shift work, and many other conditions. Consumer smartwatches also cannot diagnose schizophrenia or determine whether someone will develop psychosis.
However, persistent changes in sleep may deserve attention when they occur alongside changes in thinking, perception, mood, behavior, or daily functioning.
Patients already receiving care for psychosis or elevated psychosis risk may benefit from discussing sleep patterns with their healthcare providers. Useful information includes changes in bedtime, wake time, daytime sleeping, nighttime wakefulness, medication timing, and whether sleep worsens before psychiatric symptoms increase.
Implications for Practice
For healthcare professionals, the study suggests that asking only about average sleep duration may be insufficient.
Sleep should be evaluated across multiple nights, especially in patients with psychosis or elevated psychosis risk. Actigraphy could eventually complement clinical interviews, sleep diaries, symptom assessments, and smartphone-based monitoring. It may help identify patients with distinct sleep phenotypes and support more individualized treatment planning.
The findings also strengthen the case for treating sleep as a core component of psychiatric care rather than as a secondary symptom. Potential interventions may include cognitive behavioral therapy for insomnia, medication review, structured daytime activity, circadian rhythm management, and treatment of conditions such as sleep apnea.
However, the study did not test whether treating sleep variability reduces psychosis risk or improves long-term outcomes.
Important Limitations
This was a meta-analysis of case-control studies, so it cannot show that sleep variability causes psychosis.
It also cannot determine whether sleep changes predict progression from a high-risk state to a psychotic disorder. No included study was rated as having a low risk of bias. Five were rated as high risk, and the remaining studies had some concerns.
Several findings also showed substantial statistical heterogeneity, meaning results varied across studies. The high-risk group was represented by relatively few studies, making some findings less stable.
Finally, actigraphy estimates sleep from movement and cannot measure sleep stages, breathing abnormalities, or brain activity in the way a formal sleep study can.
What Comes Next
Researchers now need prospective studies that follow people at clinical high risk for psychosis over time. These studies should determine whether specific sleep patterns predict symptom progression, recovery, relapse, or treatment response.
Individual-level data will also be necessary to identify whether distinct subgroups exist, such as short sleepers, long sleepers, fragmented sleepers, and people with highly inconsistent sleep schedules.
Randomized trials will then be needed to test whether stabilizing sleep improves psychiatric outcomes.
Bottom Line
People across the psychosis spectrum appear to have more varied sleep patterns than healthy individuals, even when average sleep measurements look similar.
Sleep variability may eventually become a useful digital biomarker for stratified psychiatric care. For now, it should be viewed as a promising research signal, not a diagnostic test.