Sleep Measures Research Articles

Sleep microstructure in patients with systemic sclerosis: A cyclic alternating pattern analysis study.

The cyclic alternating pattern (CAP) is a cyclic variation of sleep electroencephalogram activity within non-rapid eye movement (non-REM) sleep and increased CAP is the marker of sleep instability. The present study aimed to examine the expression of cyclic alternating pattern in non-REM sleep in patients with systemic sclerosis (SSc) and to compare these findings with the control group. Thirty-one patients with SSc were compared with matched controls by age, gender, body mass index, and apnea-hypopnea index (AHI). Sleep measurements were obtained by standard polysomnography with conventional sleep scoring. A CAP analysis was performed and verified by certified somnologists. The sleep parameters of the SSc and control groups were similar for sleep efficiency, sleep stage percents N1, N2, N3, sleep latency, and minimum oxygen saturation (p = 0.627, p = 0.693, p = 0.530, p = 0.736, p = 0.772, and p = 0.693, respectively). The SSc patients presented a higher arousal and periodic limb movement index. The CAP analyses showed that SSc patients had higher CAP numbers, phase A2 index, A3 duration, and lower A1 duration (p = 0.032, p = 0.016, p = 0.016, and p = 0.016, respectively). Overall the phase A2 index, A2 total time during non-REM sleep were significantly higher and the A1 duration was significantly lower in SSc patients, although sleep efficiency and the distribution of sleep macro-structure seem to be similar to the control group. This study emphasises that microstructure analysis performed with CAP provides information that would otherwise be lost if only macrostructure analysis were considered.

Cognition and objective sleep quality in post-COVID-19 patients

In the current study, we aimed (i) to evaluate sleep quality via wrist actigraphy monitoring of nonhospitalized and hospitalized post-COVID-19 condition (PCC) participants; (ii) to correlate actigraphy measures with subjective measures of sleep quality, such as the Pittsburgh Sleep Quality Index (PSQI); and (iii) to investigate whether total sleep time or sleep efficiency could affect PCC cognitive performance. We included 49 individuals with PCC from the NAUTILUS Project (NCT05307549 and NCT05307575) who were monitored for 1 week via actigraphy and who were also assessed with a comprehensive neuropsychological battery and the PSQI. We found that there were significant differences between nonhospitalized PCCs and hospitalized PCCs in the number of awakenings. We also found a correlation between the total sleep time of both measures (actigraphy and PSQI), but we did not observe correlations between objective and subjective parameters of latency and sleep efficiency. Regarding cognition and actigraphy measures, there was a trend of statistical significance in the performance of immediate visual memory, attention span and social cognition according to sleep efficiency. In conclusion, results indicate that although the PSQI provides clinically relevant indicators of sleep, there are divergent results between self-reported and objective sleep measures (actigraphy). Furthermore, we found a tendency toward statistical significance in cognitive performance in PCC participants according to their sleep efficiency which could indicate that is more important for cognitive function of post-COVID-19 patients than total sleep time.

Co-occurring mental health problems in adolescents with ADHD and sleep problems.

Sleep problems are highly prevalent and impairing in adolescents with ADHD. However, their relation with co-occurring mental health problems is still unclear. This study assessed whether adolescents with ADHD, with and without self-reported sleep problems, differ from each other in co-occurring mental health problems, and whether they differ from adolescents without ADHD. Furthermore, we examined whether the adolescents with ADHD and self-reported sleep problems do indeed have more disturbed sleep than the other two groups and lastly, whether these sleep differences are moderated by co-occurring mental health problems. Three groups of adolescents (13-17 years): 1) with ADHD and comorbid self-reported sleep problems (N=56), 2) with ADHD but without self-reported sleep problems (N=25), and 3) without ADHD (N=56) were assessed. Group comparisons were done for symptoms of co-occurring mental health problems, self- and parent-reported sleep problems, and objective and subjective sleep parameters. Exploratively, moderating effects of co-occurring mental health problems on sleep differences between groups are examined. Compared to those without self-reported sleep problems, adolescents with ADHD and comorbid self-reported sleep problems experienced significantly more co-occurring symptoms of mental health problems, especially depression. They also scored higher on all sleep problems, and had a longer sleep onset latency and lower sleep efficiency based on subjective and objective sleep measures. Depression and anxiety moderated objectively measured sleep differences. Co-occurring mental health problems, especially depressive symptoms, are more prevalent in adolescents with ADHD and sleep problems and partially moderate the relation with sleep. This indicates that when adolescents with ADHD present with sleep problems in clinical practice, it is essential to also assess symptoms and other mental health problems and vice-versa.

Longitudinal assessment of objective sleep and power output in Division I collegiate baseball athletes.

Many college athletes experience insufficient sleep due to athletic, academic, and social constraints. While prior studies have observed cross-sectional associations between poor sleep and performance in athletes, few studies have longitudinally assessed performance variations in relation to sleep measures. We investigated whether objectively measured sleep assessments were associated with peak power output improvements during a fall season of Division I collegiate baseball players. Peak power output was assessed weekly for 12weeks in 24 male collegiate baseball players (age: 21±1years). Objective sleep (Oura ring) was assessed over the final 6weeks to determine total sleep time, sleep efficiency, and other assessments of sleep quality, including the proportion of nights in which athletes maintained total sleep time ≥7hours or sleep efficiency ≥90%. Bivariate correlations between sleep measures and peak power output were performed. Greater improvements in peak power output throughout the fall season were associated with higher total sleep time (r=0.429, p=.036), higher sleep efficiency (r=0.411, p=.046), and fewer nighttime awakenings (r=-0.495, p=.014). Furthermore, the rate of change in peak power output was associated with the proportion of nights in which athletes maintained total sleep time ≥7hours (r=0.557, p=.005) or sleep efficiency ≥90% (r=0.509, p=.011). These findings support an association between adequate sleep duration, quality, and consistency in training season performance trajectories in college athletes. Data will be made available upon reasonable request by the corresponding author.

Smartwatches and measurement of physical activity, sedentary behavior, and sleep: a scoping review

Smartwatches and measurement of physical activity, sedentary behavior, and sleep: a scoping review

Better objective sleep quality is associated with higher gut microbiota richness in older adults.

Aging is associated with disrupted sleep patterns, such as fragmented sleep and reduced efficiency, leading to negative health outcomes. There is evidence of a bidirectional relationship between sleep and gut microbiota, which plays a key role in the gut-brain axis and overall health. However, studies on this relationship in older adults have limited generalizability and show conflicting results, highlighting the need for further research. This study aimed to investigate the associations between sleep quality and gut microbiota composition in healthy Chinese older adults using subjective and objective sleep measures to capture various aspects of sleep quality and explore potential impacts on emotional well-being and cognitive performance. Subjective sleep quality was assessed using the PittsburghSleep Quality Index(PSQI) questionnaire, while objective sleep quality was measured with actigraphy. Gut microbiota sequencing was performed on stool samples. The results show a robust positive association between gut microbiota richness and objective sleep quality in older adults, independent of subjective sleep quality and demographics, lifestyle, and health covariates. However, no significant link was found between gut microbiota richness and subjective sleep quality. Specific taxa like Bacteroidetes, Ruminococcus, Collinsella, Veillonella, and Holdemania were tentatively linked to sleep quality. These findings emphasize the connection between sleep quality and gut microbiota composition in older adults with potential research and clinical implications, improving our understanding of the mechanisms underlying the sleep-gut microbiota relationship and guiding the development of interventions for improving both sleep quality and gut health in older adults.

Exploring the link between dietary inflammatory index, inflammatory biomarkers, and sleep quality in adults with obesity: a pilot investigation.

Obesity is known to be associated with inflammation and impaired sleep quality. In addition, the anti-inflammatory properties of the daily diet provide positive effects on health. The aim of this study was to investigate the relationship between the inflammatory index of the diet consumed by people with obesity and inflammatory biomarkers and sleep quality. This study included 124 people with obesity (F: 75; M: 49) with a mean age of 42.20 ± 11.00 years, who presented to a dietary outpatient clinic in Malatya between November 2021 and May 2022. Three-day dietary intake records were collected to calculate Dietary Inflammatory Index (DII) scores, which were then compared with inflammatory biomarkers, anthropometric measurements, and sleep quality measures. Among the biochemical parameters, C-reactive protein (CRP) was found to be significantly higher in the groups with higher DII score (p = 0.006), and CRP (r = 0.258; p = 0.004) and total cholesterol (r = -0.243; p = 0.007) increased significantly with increasing inflammatory score of the diet. As the inflammatory burden of the diet consumed by the participants increased, their Body Mass Index (BMI) also increased (p = 0.009). No significant correlation was found between DII and sleep quality (p = 0.348). These findings suggest that an anti-inflammatory diet can effectively reduce inflammation and BMI in people with obesity, but has a limited effect on sleep quality. Therefore, it is recommended that dietitians integrate anti-inflammatory dietary strategies for people with obesity into their clinical practice.

Subjective sleep quality, but not objective sleep measures, mediates the relationship between pre-sleep worrying and affective wellbeing.

Pre-sleep worrying is associated with sleep disturbance, which in turn is associated with impaired affective wellbeing. However, studies examining the fine-grained temporal order of these variables are still lacking. In particular, within-person mediation of the association between pre-sleep worrying and the following day's affective wellbeing by subjective and objective indicators of sleep has not been tested yet. This study investigates the extent to which pre-sleep worrying predicts positive/negative affect the following day, and whether subjective/objective sleep disturbances are possible mediators for this relationship. Data from two experience sampling studies were pooled for the analyses, resulting in a total sample of 220 participants aged between 18 and 30 years (M = 23.2 years, SD = 2.8). The hypotheses were tested at both the between- and within-subject level using causal mediation analysis. The within-subject analyses revealed partial mediation of the relationship between pre-sleep worrying and positive as well as negative affect the next day by subjective sleep quality. By contrast, sleep as measured by actigraphy appears not to be relevant for the link between pre-sleep worrying and affective wellbeing the following day. Baseline levels of depressive symptoms and sleep disturbances did not moderate the associations between pre-sleep worrying, sleep indices and affective states the following day. Improving perceived sleep quality by addressing pre-sleep worrying could be a potential avenue to enhance affective wellbeing and promote better mental health in young adults.

The Impact of Sleep on Cognitive Function in Youth Athletes

ABSTRACT Objectives This study sought to characterize the sleep of youth athletes and investigate relationships between sleep measures and cognitive function. Method Youth netball athletes (n = 19, age; 16.58 ± 1.26 years), wore an Actigraph wGT3X-BT and completed a daily sleep diary over 8 weeks. Cognitive function was measured every 2 weeks using Inquisit online software. Data were analyzed using generalized estimating equations to investigate the relationship between sleep and cognitive function. Results Youth athletes averaged <7 hr of sleep each night. Increases in total sleep time (β= −.13, CI [−.21, −.06]) sleep efficiency (β= −.49, CI [−.87, −.11]) and sleep quality rating (β= −12.23, CI [−21.26, −3.20]) resulted in a decrease in reaction time (p < .05). Increases in sleep onset latency (β= .04, CI [.02, .06]) and wake after sleep onset (β= .03, CI [.01, .05]) resulted in an increased error count for the digit symbol substitution task (p < .05). Conclusion Findings show that many youth athletes obtain less than the recommended amount of sleep. This is concerning given the importance of sleep for adolescent development. Inadequate sleep in youth athletes appears to negatively affect cognitive function. Future research should investigate the impact of inadequate sleep in youth athletes on athletic and academic performance.

Exploring the Psychological and Physiological Insights Through Digital Phenotyping by Analyzing the Discrepancies Between Subjective Insomnia Severity and Activity-Based Objective Sleep Measures: Observational Cohort Study.

Insomnia is a prevalent sleep disorder affecting millions worldwide, with significant impacts on daily functioning and quality of life. While traditionally assessed through subjective measures such as the Insomnia Severity Index (ISI), the advent of wearable technology has enabled continuous, objective sleep monitoring in natural environments. However, the relationship between subjective insomnia severity and objective sleep parameters remains unclear. This study aims to (1) explore the relationship between subjective insomnia severity, as measured by ISI scores, and activity-based objective sleep parameters obtained through wearable devices; (2) determine whether subjective perceptions of insomnia align with objective measures of sleep; and (3) identify key psychological and physiological factors contributing to the severity of subjective insomnia complaints. A total of 250 participants, including both individuals with and without insomnia aged 19-70 years, were recruited from March 2023 to November 2023. Participants were grouped based on ISI scores: no insomnia, mild, moderate, and severe insomnia. Data collection involved subjective assessments through self-reported questionnaires and objective measurements using wearable devices (Fitbit Inspire 3) that monitored sleep parameters, physical activity, and heart rate. The participants also used a smartphone app for ecological momentary assessment, recording daily alcohol consumption, caffeine intake, exercise, and stress. Statistical analyses were used to compare groups on subjective and objective measures. Results indicated no significant differences in general sleep structure (eg, total sleep time, rapid eye movement sleep time, and light sleep time) among the insomnia groups (mild, moderate, and severe) as classified by ISI scores (all P>.05). Interestingly, the no insomnia group had longer total awake times and lower sleep quality compared with the insomnia groups. Among the insomnia groups, no significant differences were observed regarding sleep structure (all P>.05), suggesting similar sleep patterns regardless of subjective insomnia severity. There were significant differences among the insomnia groups in stress levels, dysfunctional beliefs about sleep, and symptoms of restless leg syndrome (all P≤.001), with higher severity associated with higher scores in these factors. Contrary to expectations, no significant differences were observed in caffeine intake (P=.42) and alcohol consumption (P=.07) between the groups. The findings demonstrate a discrepancy between subjective perceptions of insomnia severity and activity-based objective sleep parameters, suggesting that factors beyond sleep duration and quality may contribute to subjective sleep complaints. Psychological factors, such as stress, dysfunctional sleep beliefs, and symptoms of restless legs syndrome, appear to play significant roles in the perception of insomnia severity. These results highlight the importance of considering both subjective and objective assessments in the evaluation and treatment of insomnia and suggest potential avenues for personalized treatment strategies that address both psychological and physiological aspects of sleep disturbances. Clinical Research Information Service KCT0009175; https://cris.nih.go.kr/cris/search/detailSearch.do?seq=26133.

Wearable Neurotechnology for the Treatment of Insomnia: The Study Protocol of a Prospective, Placebo-Controlled, Double-Blind, Crossover Clinical Trial of a Transcranial Electrical Stimulation Device

Sleep disruption and deprivation are epidemic problems in the United States, even among those without a clinically diagnosed sleep disorder. Military service members demonstrate an increased risk of insomnia, which doubles after deployment. This study will investigate the ability of a translational device, Teledyne PeakSleep™ (Teledyne Scientific &amp; Imaging, Durham, NC, USA), to reduce sleep onset latency and the time spent awake after sleep onset, with improvement in the subjective benefits of sleep for patients with insomnia by enhancing the brain rhythms within the frontal lobe implicated in slow wave generation. During this crossover trial, patients will use the wearable neurotechnology prototype headband, which delivers &lt; 14 min of frontal short duration repetitive–transcranial electrical stimulation over a 30 min period immediately before trying to fall asleep. Using active stimulation versus a sham paradigm, we will compare actigraphy data, physiological data, and subjective sleep measures against a pre-treatment baseline in the same patient over the course of the 8-week study. If successful, PeakSleep™ could address the final common pathway in insomnia, namely the onset and maintenance of slow-wave sleep (SWS), and accordingly has the potential to enhance sleep onset in a wide range of individuals, most importantly warfighters in whom efficient sleep onset may be critical for operational success.

Calcineurin governs baseline and homeostatic regulations of non–rapid eye movement sleep in mice

Sleep need accumulates during waking and dissipates during sleep to maintain sleep homeostasis (process S). Besides the regulation of daily (baseline) sleep amount, homeostatic sleep regulation commonly refers to the universal phenomenon that sleep deprivation (SD) causes an increase of sleep need, hence, the amount and intensity of subsequent recovery sleep. The central regulators and signaling pathways that govern the baseline and homeostatic sleep regulations in mammals remain unclear. Here, we report that enhanced activity of calcineurin Aα (CNAα)-a catalytic subunit of calcineurin-in the mouse brain neurons sharply increases the amount (to ~17-h/d) and delta power-a measure of intensity-of non-rapid eye movement sleep (NREMS). Knockout of the regulatory (CnB1) or catalytic (CnAα and CnAβ) subunits of calcineurin diminishes the amount (to ~4-h/d) and delta power of baseline NREMS, but also nearly abrogates the homeostatic recovery NREMS following SD. Accordingly, mathematical modeling of process S reveals an inability to accumulate sleep need during spontaneous or forced wakefulness in calcineurin deficient mice. Moreover, calcineurin promotes baseline NREMS by antagonizing wake-promoting protein kinase A and, in part, by activating sleep-promoting kinase SIK3. Together, these results indicate that calcineurin is an important regulator of sleep need and governs both baseline and homeostatic regulations of NREMS in mice.

Psychophysiological stress response, emotion dysregulation and sleep parameters as predictors of psychopathology in adolescents and young adults.

Increased emotional reactivity to stress, emotional dysregulation and sleep disturbances are interdependent trans-diagnostic processes that are present in internalising disorders such as depression and anxiety disorders. This study investigated which objective and subjective parameters of stress reactivity, sleep and emotional processing would predict symptoms of anxiety and depression in adolescents and young adults. Participants were adolescents and young adults between the ages of 14 to 21 (N = 106, 25[24 %] male, M age = 17.93). Heart rate, heart rate variability, and subjective stress levels were measured before, during and after a stress induction using the Trier Social Stress Test (TSST). Questionnaires on internalising symptoms, emotion dysregulation, and sleep quality were used. For seven consecutive nights, objective sleep parameters were measured with a wearable device. Heart rate and heart rate variability after (but not during) the stress induction and emotion dysregulation predicted depressive and anxiety symptoms. Lower subjective sleep quality (but not the objective sleep parameters) was associated with depressive and anxiety symptoms. Emotion dysregulation mediated the relationship between sleep quality and depressive symptoms. A cross-sectional design, no measurement of daily activity or naps, and only self-report measures of depressive and anxiety symptoms as well as emotion dysregulation. The findings of elevated cardiovascular activation after - but not during - the stress induction and emotion dysregulation underlines problems in regulating and recovering from stress as predictors of youth internalising psychopathology. Differences between subjective and objective measures of sleep and stress reactivity suggests a role of cognitive biases in these domains.

Associations of fat, bone, and muscle indices with disease severity in patients with obstructive sleep apnea hypopnea syndrome

PurposeTo investigate the relationship between obstructive sleep apnea hypopnea syndrome (OSAHS) severity and fat, bone, and muscle indices.MethodsThis study included 102 patients with OSAHS and retrospectively reviewed their physical examination data. All patients underwent polysomnography, body composition analysis, dual-energy X-ray absorptiometry, computed tomography (CT) and blood test. Correlation and multiple linear regression analyses were performed using SPSS 22.0.ResultsAmong the fat indices, fat mass (FM) (r = 0.27–0.43), body fat percentage (BFP) (r = 0. 25–0.35), visceral fat area (VFA) (r = 0.28–0.40) and trunk fat mass (TFM) (r = 0.26–0.34) were positively correlated with hypopnea index (HI), apnea-hypopnea index (AHI), oxygen desaturation index (ODI), and percent of time spent with oxygen saturation below 90% (T90%), respectively, and negatively correlated with mean pulse oxygen saturation (SpO2) (r= -0.28–-0.41). For bone indexes, T8, T9, T11, L1-CT value, mean vertebral CT value and 25-Hydroxyvitamin D3 were positively correlated with mean SpO2 (r = 0.23–0.32), respectively. For muscle indexes, pectoralis muscle density (PMD) was negatively correlated with HI, AHI, and ODI (r= -0.20–-0.36) and positively correlated with mean SpO2 (r = 0.26). In separate models predicting sleep measures, AHI increased by 0.36, 0.29, 0.34 and 0.25 events/h per unit increase in FM, BFP, VFA, and triglyceride (TG), respectively. AHI decreased by 0.27 per unit increase in PMD. T90% increased with FM, BFP, VFA, WHR, TG and total cholesterol (TC), but decreased with appendicular skeletal muscle mass (ASM) and PMD respectively.ConclusionHigher fat levels and lower vertebral CT values, muscle mass and density correlated with a higher degree of OSAHS severity. Intermittent hypoxia may affect fat, bone, and muscle metabolism in patients with OSAHS.

Long-term follow-up of the impact of brief sleep and lifestyle interventions in infancy on BMI z-score at 11 years of age: The POI randomized controlled trial.

To determine whether BMI differences observed at 5 years of age, from early intervention in infancy, remained apparent at 11 years. Participants (n = 734) from the original randomized controlled trial (n = 802) underwent measures of body mass index (BMI), body composition (DXA), sleep and physical activity (24-h accelerometry, questionnaire), diet (repeated 24-h recalls), screen time (daily diaries), wellbeing (CHU-9D, WHO-5), and family functioning (McMaster FAD) around their 11th birthday. Following multiple imputation, regression models explored the effects of two interventions ('Sleep' vs. 'Food, Activity and Breastfeeding' [FAB]) using a 2 × 2 factorial design. Five hundred twelve children (48% female, mean [SD] age 11.1 [0.1] years) returned for the 11-year assessment (63% of original sample). Significant differences in BMI z-score (mean difference; 95% CI: -0.16; -0.41, 0.08) or the risk of overweight (including obesity) (odds ratio; 95% CI: 0.85; 0.56, 1.29) were no longer observed between children who had received the sleep intervention compared with those who had not. By contrast, children who had received the FAB intervention had greater BMI z-scores (0.24; 0.01, 0.47) and a higher risk of obesity (1.56; 1.03, 2.36) than children not enrolled in FAB. No significant differences were observed in any lifestyle variables nor wellbeing measures across all groups. Sustained reductions in BMI and obesity risk from an early sleep intervention were not apparent 9 years later, whereas a more traditional lifestyle intervention resulted in increased rates of obesity, not explained by any differences in lifestyle behaviours measured. ClinicalTrials.gov number NCT00892983, https://clinicaltrials.gov/study/NCT00892983.

Preliminary feasibility and efficacy of a brief behavioural treatment for insomnia after acquired brain injury: A case series.

Insomnia after acquired brain injury (ABI) is common and can negatively impact an individual's rehabilitation, recovery, and quality of life. The present study investigated the feasibility and preliminary efficacy of a Brief Behavioural Treatment for Insomnia (BBTI) in a community sample following ABI. Ten participants were recruited. Seven participants attended four weekly sessions of BBTI and kept a daily sleep diary. Participants completed a semi-structured sleep interview at baseline and self-report measures of sleep, anxiety, and depression pre- and post-treatment as well as a treatment acceptability questionnaire post-treatment. Follow-up data were collected at 1-, 2-, and 3-months post-treatment. Visual analyses of the data were performed on a case-by-case basis. Five of the seven participants (71%) no longer met the criteria for insomnia disorder on the Sleep Condition Indicator (SCI) post-treatment. Treatment effects on sleep outcomes were either maintained or augmented at follow-ups. BBTI was found to be well tolerated, as evidenced by the high overall retention rates (70%) and positive feedback on the treatment acceptability questionnaire. These results provide preliminary evidence of BBTI being both feasible to use and potentially efficacious in individuals with post-brain-injury insomnia. Larger-scale randomised controlled trials are needed to establish the effectiveness of BBTI following ABI.

Feasibility and acceptability for LION, a fully remote, randomized clinical trial within the VA for light therapy to improve sleep in Veterans with and without TBI: An MTBI2 sponsored protocol.

Sleep-wake disturbances frequently present in Veterans with mild traumatic brain injury (mTBI). These TBI-related sleep impairments confer significant burden and commonly exacerbate other functional impairments. Therapies to improve sleep following mTBI are limited and studies in Veterans are even more scarce. In our previous pilot work, morning bright light therapy (MBLT) was found to be a feasible behavioral sleep intervention in Veterans with a history of mTBI; however, this was single-arm, open-label, and non-randomized, and therefore was not intended to establish efficacy. The present study, LION (light vs ion therapy) extends this preliminary work as a fully powered, sham-controlled, participant-masked randomized controlled trial (NCT03968874), implemented as fully remote within the VA (target n = 120 complete). Randomization at 2:1 allocation ratio to: 1) active: MBLT (n = 80), and 2) sham: deactivated negative ion generator (n = 40); each with identical engagement parameters (60-min duration; within 2-hrs of waking; daily over 28-day duration). Participant masking via deception balanced expectancy assumptions across arms. Outcome measures were assessed following a 14-day baseline (pre-intervention), following 28-days of device engagement (post-intervention), and 28-days after the post-intervention assessment (follow-up). Primary outcomes were sleep measures, including continuous wrist-based actigraphy, self-report, and daily sleep dairy entries. Secondary/exploratory outcomes included cognition, mood, quality of life, circadian rhythm via dim light melatonin onset, and biofluid-based biomarkers. Participant drop out occurred in <10% of those enrolled, incomplete/missing data was present in <15% of key outcome variables, and overall fidelity adherence to the intervention was >85%, collectively establishing feasibility and acceptability for MBLT in Veterans with mTBI.

Poor self-reported sleep is associated with prolonged white matter T2 relaxation in psychotic disorders.

Psychotic disorders are characterized by white matter (WM) abnormalities; however, their relationship with the various aspects of illness presentation remains unclear. Sleep disturbances are common in psychosis, and emerging evidence suggests that sleep plays a critical role in WM physiology. Therefore, it is plausible that sleep disturbances are associated with impaired WM integrity in these disorders. To test this hypothesis, we examined the association of self-reported sleep disturbances with WM transverse (T2) relaxation times in a cross-diagnostic sample of patients with psychosis. A total of 28 patients with psychosis (11 schizophrenia spectrum disorders and 17 bipolar disorder with psychotic features) were included. Metabolite (N-acetyl aspartate, choline, and creatine) and water T2 relaxation times were measured in the anterior corona radiata at 4T. Sleep was evaluated using the Pittsburgh Sleep Quality Index (PSQI). PSQI total score showed a moderate to strong positive correlation with water T2 (r = 0.64, p< 0.001). Linear regressions showed that this association was independent of the overall severity of depressive, manic, or psychotic symptoms. In our exploratory analysis, sleep disturbance was correlated with free water percentage, suggesting that increased extracellular water may be a mechanism underlying the association of disturbed sleep and prolonged water T2 relaxation. Our results highlight the connection between poor sleep and WM abnormalities in psychotic disorders. Future research using objective sleep measures and neuroimaging techniques suitable to probe free water is needed to further our insight into this relationship.

Mobile Sleep Lab: Comparison of polysomnographic parameters with a conventional sleep laboratory.

In remote areas, visiting a laboratory for sleep testing is inconvenient. We, therefore, developed a Mobile Sleep Lab in a bus powered by fuel cells with two sleep measurement chambers. As the environment in the bus could affect sleep, we examined whether sleep testing in the Mobile Sleep Lab was as feasible as in a conventional sleep laboratory (Human Sleep Lab). We tested 15 healthy adults for four nights using polysomnography (the first two nights at the Human Sleep Lab or Mobile Sleep Lab with a switch to the other facility for the next two nights). Sleep variables of the four measurements were used to assess the discrepancy of different places or different nights. No significant differences were found between the laboratories other than the percentage of total sleep time in stage N3. Next, we analyzed the intraclass correlation coefficient to evaluate the test-retest reliability. The intraclass correlation coefficient between these two measurements: the Human Sleep Lab and Mobile Sleep Lab showed similar reliability for the same sleep variables. The intraclass correlation coefficient revealed that several sleep indexes, such as total sleep time, sleep efficiency, wake after sleep onset, percentage of stage N1, and stage R latency, showed poor reliabilities (<0.5) based on Koo and Li's criteria. In contrast, the percentage of stage N3 showed moderate (0.5-0.75) or good (0.75-0.9) reliabilities. As almost all sleep variables showed no difference and same level of test-retest reliability between the Mobile Sleep Lab and Human Sleep Lab, the Mobile Sleep Lab might be suitable for conducting polysomnography as a conventional sleep laboratory. The reduction in N3 in the Mobile Sleep Lab should be scrutinized in the larger sample, including sleep disorders. Practical application of the Mobile Sleep Lab can transform sleep medicine in remote areas.

Meta-narrative review: the impact of music therapy on sleep and future research directions.

Sleep is essential to human health, yet 27% of the global population suffers from sleep issues, which often lead to fatigue, depression, and impaired cognitive function. While pharmacological treatments exist, non-pharmacological approaches like music therapy have shown promise in enhancing sleep quality. This review, analyzing 27 studies with various experimental paradigms, confirms that music therapy significantly improves subjective sleep quality, largely by alleviating anxiety and regulating mood through perceptual pathways. However, the effects on objective sleep measures remain inconclusive, suggesting that individual differences may play a significant role. Future research should focus on refining intervention designs that integrate both subjective and objective sleep assessments to better elucidate the physiological and psychological mechanisms of music therapy. Key recommendations include personalized music selection, development of age-appropriate interventions, and minimization of external interferences to maximize therapeutic outcomes. Additionally, incorporating variables like psychological status, lifestyle, and environmental factors may offer a more comprehensive understanding of music therapy's long-term adaptability and effectiveness for diverse populations. This review offers critical research directions and practical support for future applications of music therapy in sleep health.