Neurocognition After Perturbed Sleep

Study Overview
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Brief Summary
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Individuals with schizophrenia display a wide range of neurocognitive difficulties resulting in functional impairment and disability. Extensive evidence indicates insomnia and sleep disturbances play a substantial role in degrading cognitive functioning. However, the putative impact of insomnia and sleep disturbances on neurocognition and daily functioning has not been investigated in people with schizophrenia. The goal of this study is to characterize sleep in individuals with schizophrenia and quantify its impact on neurocognition and daily functioning.

Detailed Description
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Individuals with SZ display a broad range of neurocognitive difficulties that have been identified as major determinants of poor functioning and disability, thus representing an important public health concern and a focal target for interventions. Extensive research literatures converge in highlighting the critical role insomnia and sleep disturbances play in degrading neurocognitive functioning. Such sleep disturbances result in clinical presentations similar to neurocognitive difficulties commonly observed in people with SZ. While insomnia and sleep disturbances are highly prevalent in people with SZ, there are scant data on the impact of sleep disturbances on neurocognition in SZ, and no data quantifying their influence on daily functioning. Thus, sleep disturbances remain poorly understood and modeled in SZ, their impact is rarely considered in clinical trials, and they remain largely unaddressed by clinicians. To address this gap in knowledge, the primary aim of this study is to characterize sleep in individuals with SZ and quantify its impact on neurocognition and daily functioning. Employing an experimental, within-person, repeated assessment design, the study team will characterize sleep architecture, duration, and quality along with cognitive, electrophysiological, biomarkers and daily functioning sequelae in 40 individuals with SZ. Participants will first complete a week-long, in-home characterization of sleep duration and quality using actigraphy and a sleep diary. Next, they will complete two overnight polysomnography examinations employing two sleep schedules: 1) undisturbed sleep; and 2) restricted sleep (4 hours). As part of these assessments, participants will provide blood samples for biomarkers analyses and complete EEG-indexed memory tasks pre- and post-sleep, along with a post-sleep battery of neurocognitive functioning. Finally, participants will complete a 3-day ambulatory assessment using actigraphy and smartphones to explore the impact of each sleep schedule on real-world daily functioning including symptoms, emotion regulation, and mood.

Official Title
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Neurocognition After Perturbed Sleep (NAPS)

Conditions
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Schizophrenia

Intervention / Treatment
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* Behavioral: Overnight polysomnography examinations


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Females or males age 18-60 years DSM-5 diagnosis of schizophrenia, schizoaffective, or schizophreniform disorder Taking antipsychotic medication for >7 weeks and on current doses for 4 weeks, and/or injectable depot antipsychotics with no change in the last 3 months Capacity to understand all the potential risks and benefits of the study. Exclusion Criteria: DSM-5 alcohol/substance diagnosis (except nicotine) within the last 6 months Taking medications affecting sleep propensity or architecture (other than antipsychotic medication) Initiation of medications known to impact cognition in previous 4 weeks or any change in doses during this period History of seizures/head trauma with loss of consciousness (>10 min) resulting in cognitive sequelae Medical or neurological conditions that could interfere with participation (e.g., untreated hypothyroidism Mental retardation Narcolepsy REM behavior disorder, parasomnias) Pregnant/ nursing Serious homicidal/suicidal risk (past 6 months) Moderate or more severe disorganization (PANSS≥4) Poor English reading ability (WTAR<7) Individuals employed as vehicle drivers/train operators or have occupations in which lapses in sustained vigilance would compromise safety Night shift workers or those with irregular sleep-wake rhythms (based on the week-long home actigraphy; i.e., average bedtime of 11pm±2 hours) Participation in the past 3 months in cognition study

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Undisturbed Sleep<br>8 hours sleep - Subjects randomized to the undisturbed sleep will be instructed to go to sleep at 11pm, and awoken at 7am. | Behavioral: Overnight polysomnography examinations<br>* sleep lab for overnight polysomnography examinations<br>|
| Experimental: Restricted Sleep<br>4 hours sleep - Subjects randomized to the restricted sleep will be instructed to go to sleep at 3am and awoken at 7am. | Behavioral: Overnight polysomnography examinations<br>* sleep lab for overnight polysomnography examinations<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| MATRICS Consensus Cognitive Battery (MCCB) | The composite score of the MATRICS Consensus Cognitive Battery (MCCB) will serve as a primary neurocognitive outcome. Neurocognitive functioning is indexed on the MCCB via T scores, with a mean of 50 and a SD of 10. Thus, higher scores indicate better neurocognitive performance, with T-scores of 70+ (i.e., 2 SD's over the mean) suggestive of exceptionally strong neurocognitive abilities. | Day 2, immediate upon wakening | 
| MATRICS Consensus Cognitive Battery (MCCB) | The composite score of the MATRICS Consensus Cognitive Battery (MCCB) will serve as a primary neurocognitive outcome. Neurocognitive functioning is indexed on the MCCB via T scores, with a mean of 50 and a SD of 10. Thus, higher scores indicate better neurocognitive performance, with T-scores of 70+ (i.e., 2 SD's over the mean) suggestive of exceptionally strong neurocognitive abilities. | Day 16, immediate upon wakening | 
| Polysomnography | Polysomnography will be used to characterize sleep including - latency, duration, continuity, and architecture assessed during over a night sleep. | Days 1-2 during restricted sleep and undisturbed sleep | 
| Polysomnography | Polysomnography will be used to characterize sleep including - latency, duration, continuity, and architecture assessed during over a night sleep. | Days 15-16 during restricted sleep and undisturbed sleep | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Schizophrenia, Sleep, Cognition, Mood, Emotion Regulation, Functioning, Psychosis