Journal of Sleep Research

Study Objectives. Sleep characteristics are often estimated using self-reports, which may differ from objective measurements, a phenomenon known as sleep discrepancy. However, the factors associated with the degree of sleep discrepancy remain poorly understood. Methods. In the current study, a large healthy participant sample of the Budapest Sleep, Experiences and Traits Study (total N=267, 1899 nights) completed a 7-day protocol including mobile EEG recordings and sleep diaries, and also provided questionnaire-based reports of habitual sleep. We compared analogous sleep metrics from these three modalities, and used cross-validated LASSO regression to investigate demographic, psychological and lifestyle-related factors associated with increased sleep discrepancy across all three modalities, at both between- and within-participant levels. Results. Daily diaries estimated EEG-based sleep timing accurately (mean r=0.83), but were less accurate for sleep onset latency and quality. In contrast, questionnaire reports of habitual sleep provided inaccurate measures of even sleep timing (mean r=0.49) and considerably misestimated sleep timing and duration. Insomnia and depressive symptoms, napping, co-sleeping and personality traits were associated with increased sleep discrepancy. Conclusion. In healthy adults, questionnaires about habitual sleep provide only moderately accurate and biased estimates of actual sleep. Daily diaries provide considerably more accurate estimates, but sleep onset latency and physiological sleep quality is estimated by all self-reports less accurately than sleep timing. Sleep discrepancy is also present in healthy participants, it is particularly and its degree is affected by non-pathological characteristics. Long-term monitoring by daily diaries or wearables should be preferred to self-report questionnaires to measure sleep.

Targeted memory reactivation (TMR) during sleep can benefit recently acquired memories, but whether it can also influence memories after an initial period of consolidation remains unclear. Here, we tested whether auditory reactivation during non-rapid eye movement (NREM) sleep could strengthen declarative memories learned 24 h earlier. Twenty-six healthy young adults learned 30 sound word associations and returned the following day for a 90 min nap. During NREM sleep, participants in the Reactivation group received incomplete reminders consisting of the learned sound followed by the first syllable of the associated word, whereas the No-Reactivation group slept under the same conditions without memory related cues. Participants who received reminders showed significantly less forgetting, despite comparable training performance and sleep macroarchitecture. Across NREM sleep, reactivation was associated with greater slow oscillation and delta power, more slow oscillations and fast spindles, and greater slow oscillation spindle cooccurrence. The memory benefit remained significant after adjusting for NREM physiological measures and in sensitivity analyses restricted to overlapping physiological ranges between groups. Cue locked analyses revealed significant responses in the slow oscillation, delta, theta, and fast-spindle ranges, but the magnitude of these responses was not associated with memory change. These findings show that TMR during NREM sleep can benefit declarative memories after a 24 h consolidation interval and suggest that its effects extend beyond the immediate post-learning sleep period.

Background: Shiftwork disrupts natural sleep-wake cycles, alters light exposure patterns, and contributes to circadian misalignment. Detrimental health consequences associated with shift work include elevated risk for metabolic disorders, cardiovascular disease, cancer and all-cause mortality. Healthcare workers have one of the highest rates of shift work exposure, yet there are relatively few non-pharmacological interventions (with good evidence) developed to improve sleep outcomes in this population. Objective: A pre-post pilot interventional study assessed the acceptability and perceived effectiveness of commercial noise-masking earbuds on improving subjective sleep characteristics among National Health Service (NHS) healthcare staff working fast rotating shifts. Methods: Noise-masking sleep earbuds (Kokoon NightBuds) were worn for a pilot six-week intervention by twenty-seven NHS nurses (aged 26-43 years, 88.9% female) working fast rotating shifts from the EClocker Study. Sensors inside the earbuds were paired with a smartphone app to monitor sleep. An audio library in the smartphone app delivered personalised relaxation exercises and sleep techniques drawn from cognitive behavioural therapy for insomnia (CBT-I). A pre-post two-week monitoring period with daily smartphone-based Experience Sampling Methods (ESM) captured perceived daily sleep patterns. Acceptability and perceived effectiveness of the earbuds in promoting better sleep outcomes was assessed. Results: Use of the noise-masking sleep earbuds over a six-week period was associated with positive sleep improvement trends and elicited promising acceptability. Almost two thirds of NHS fast rotating shift nurses (63%) subjectively reported reductions in general sleep disturbance symptoms (PSQI Global), one in four experienced perceived sleep quality improvements (SQ; 25.9%), one in five reported sleeping longer (TST; 22.2%), and a third perceived falling asleep faster (SOL; 33.3%), had better sleep efficiency (SE; 33.3%) and improved daytime dysfunction (33.3%) (PSQI subcomponent scores). Sleep diaries (CSD) collected daily using smartphone-based ESM also demonstrated small improvements post-sleep earbud use; nurses reported sleeping an average 18 minutes longer (TST) and fell asleep more easily, on average 11 minutes faster (SOL). Sleep earbuds were generally well tolerated; 56% of nurses reported the earbuds as (somewhat to very) helpful, 52% reported (somewhat to strongly) falling asleep more easily (SOL), 44% felt (somewhat to strongly) their sleep quality was improved (SQ) and 30% agreed (somewhat to strongly) they slept longer (TST) and had less disturbed sleep. Conclusions: To our knowledge, this is the first study in Europe to pilot noise-masking earbuds as a potential non-pharmacological aid to improve sleep-wake behaviours or mitigate fatigue for healthcare staff. Preliminary results showed promising acceptability and (small) perceived sleep improvement trends following a targeted six-week earbud intervention in NHS fast rotating shift nurses.

Background: Sleep architecture fragmentation is common in Long COVID and dysautonomia, yet the relationship between block-level deep sleep consolidation and next-day functional wellbeing has not been characterized longitudinally in this population. We tested the hypothesis that block-level deep sleep architecture predicts next-day wellness better than aggregate stage duration. Methods: A prospective N-of-1 longitudinal study was conducted across 78 nights between January 1 and March 25, 2026 using a consumer wearable (Garmin Index Sleep Monitor). Next-day wellbeing was assessed using the Overall Feeling Score (OFS; 0-10 scale). A five-tier Architecture Group (AG) classification operationalized consolidation quality. A custom predictive model (Pendulum v5.2) quantified consolidation through block-level weighting and contextual penalties. Space weather metrics (Kp index, daily electron fluence, Load Score) were correlated with sleep architecture and OFS across same-day and lagged alignments. A secondary hierarchical regression examined illness as an independent covariate across the full dataset. Results: Architecture Group explained 56.7% of next-day OFS variance (r = 0.753, p < 0.001), compared with 17.0% for total deep sleep duration (r = 0.412) and 4.8% for the Garmin Sleep Score (r = 0.220). Pendulum v5.2 explained 43.0% of variance (r = 0.656). The deep sleep fragmentation phenotype occurred on 25.6% of nights despite adequate total deep sleep. Space weather explained 14.2% of OFS variance through architecture degradation; Load Score at 1-day lag was the strongest space weather predictor (r = -0.328, p = 0.004). A binary illness indicator explained an additional 5.7% of OFS variance beyond architecture and space weather (full-model R{superscript 2} = 55.2%), with a mean illness-night residual of -0.56 (SD = 0.36; 95% CI [-0.72, -0.40]), consistent with immune/viral flares reducing OFS through pathways independent of sleep architecture. Conclusions: Block-level deep sleep consolidation quality is a substantially stronger predictor of next-day wellbeing than total stage duration in Long COVID with dysautonomia. Space weather constitutes a measurable environmental modifier operating through architecture degradation. Immune and viral flares constitute a significant architecture-independent confound consistent with direct neuroinflammatory effects on functional capacity. This framework may be applicable across conditions where sleep architecture fragmentation plays a pathophysiological role.

Background Sleep, mood, and affective states are mutually connected. There is a paucity of studies, however, that have considered bidirectional relationships between daily sleep-affective dyads in naturalistic settings, particularly for shift workers. Objective To evaluate the dynamic and temporal interplay of daily smartphone-based self-reported sleep measurements, dimensions of affective experience and cognitive processing in UK shift working nurses. Methods The EClocker Study prospectively monitored 102 National Health Service (NHS) nurses (aged 25-61 years, 83.3% female) working standard (day shift) and non-standard (fast rotating shifts) schedules over a two-week period. Smartphone-based Experience Sampling Methodology (ESM) recorded daily sleep, mood, momentary affect and cognitive attentional functioning. Self-reported burnout, emotional dysregulation, emotion reactivity and affective dimensions (positive and negative) were also collected. Findings Overall, NHS nurses reported a high prevalence of depressive symptoms, stress, burnout and sleep-circadian rhythm disturbances. Generalised Additive Modelling (GAMs) revealed that NHS nurses higher perceived sleep quality predicted better next-day mood state, while better daytime mood was associated with reduced sleep onset latency, such that participants reported falling asleep faster. In contrast, daytime mood or affect (positive and negative) had no substantial, direct impact on nurses subjective sleep parameters (sleep quality, sleep duration, sleep efficiency). Exposure to fast rotating night shifts across the two-week study was associated with more frequent response errors on a Choice Reaction Time (CRT) cognitive task, while daytime somnolence did not adversely influence nurses momentary reaction time speeds or attentional function. Conclusions Clinically relevant sleep impairments, insomnia-related symptoms, elevated stress, and poor mood were pervasive in a sample of UK NHS nurses, regardless of shift type. Sleep quality impacted next-day mood and daytime mood impacted sleep latency, while rotating shifts led to an increase in cognitive errors. Recognising the impact of shiftwork and designing interventions to promote better sleep quality offer potential to enhance mood and performance in healthcare professionals. Clinical implications We need to implement and evaluate interventions that regularise sleep patterns and promote sleep quality to alleviate mood symptoms among frontline NHS shift workers.

Sleep is critical for memory consolidation and emotional regulation, yet the respective roles of non-rapid eye movement (NREM) and rapid eye movement (REM) sleep remain unclear. Here, using a within-subject crossover design, we recorded high-density electroencephalography (EEG) across two experimental nights while participants viewed neutral or aversive film clips in a counterbalanced order. Combining with daytime functional localizers establishing neural patterns of aversive vs. neutral emotional processing, multivariate pattern analysis revealed that the reactivation of aversive vs. neutral memory during nocturnal sleep was both stage-dependent and event-specific. In NREM sleep, valence-specific reactivation was time-locked to slow oscillation (SO)-spindle complexes but not to either event alone; in REM sleep, reactivation occurred selectively during phasic REM periods marked by rapid eye movements. Critically, NREM SO-spindle coupling percentage was associated with consolidation of temporal memories; whereas phasic REM reactivation strength was linked to overnight dissipation of negative affect. Our findings provide direct evidence that sleep reprocesses emotional experiences through dissociable stage- and event-specific mechanisms, laying out a framework for future targeted sleep-based interventions.

The prevalence of shift work-centric industries and the rise of flexible working render it crucial to investigate the health risks posed by unnatural patterns of work and sleep. Shift working in healthcare has been linked to emotional dysregulation, reduced alertness, and cognitive impacts, with Shift Work Disorder (SWD) classified as a circadian rhythm sleep-wake disorder in the DSM-5. These impacts have historically been attributed to schedule-related sleep disturbances; however certain individuals appear more acutely affected. One measure of individual inflexibility to altered routines is chronotype distinctness, an amplitude dimension of the Caen Chronotype Questionnaire (CCQ). Here, we use Structural Equation Modelling (SEM) to unravel the mechanisms by which sleep and chronotype distinctness govern the neuropsychiatric symptom profiles of a cohort of National Health Service (NHS) shift workers (n=102). We constructed a measurement model, extracting latent constructs from questionnaires for sleep disturbances (PSQI), chronotype distinctness (CCQ), mood disorder (MDQ), depression (PHQ8) and emotional reactivity (ERS), and cognitive assessments. Correlations were identified between constructs, then translated into two SEMs - day and rotating shifts respectively - with sleep and distinctness as predictors of detrimental effects. Models were tested for direct effects, significant paths, and overall model fit. We found that, whilst sleep governed fatigue-based symptoms in day-shift workers, chronotype distinctness determined the severity of adverse effects in rotating-shift workers, including mood disorders and cognitive impairments. We surmise that high chronotype distinctness should be considered a risk factor for adverse effects surrounding night and rotating-shift work, and that interventions should incorporate chronotype-specific remediation.

Background: Higher Body Mass Index (BMI) is an established risk factor of sleep disturbance. It is not known if the effect is homogeneous across the lifecourse or if there is a particular time point in life that might be best to target. Methods: Two-sample Mendelian randomization (MR) was used to investigated the effect of childhood adiposity (adjusting on adulthood adiposity and obstructive sleep apnea (OSA)) on insomnia, morning chronotype, sleep duration, daytime sleepiness and daytime napping. Similarly, total, and direct effect of adulthood adiposity on these outcomes was explored. We used summary statistics from a genome-wide association study (GWAS) of UK Biobank for childhood and adulthood adiposity (n=453,169) and large-scale consortia of OSA (Million Veteran Program) (n=410,268), insomnia, and chronotype (23andMe) (n=1,978,022 and n=248,1000, respectively). Results: Two-sample univariable MR analysis provided no evidence of an effect of genetically predicted childhood adiposity on later life insomnia (Odds ratio (OR)= 0.94, 95% Confidence interval (CI)= 0.87, 1.03). Whereas, multivariable MR (adjusted for adulthood adiposity) analysis provide strong evidence of direct protective effect of genetically predicted childhood adiposity on later life insomnia (OR= 0.70, CI= 0.64, 0.77). Further, both in univariable and multivariable MR, a strong positive effect of increased childhood body size on morning chronotype was observed (OR= 1.16, CI= 1.01, 1.33 and OR= 1.36, CI= 1.15, 1.62, respectively) after accounting for adulthood body size. In both analysis the estimate did not change considerably after aditionally adjusting for OSA. However, childhood and adulthood adiposity found to be associated with OSA and OSA with insomnia. In both univariable and multivariable analysis, increased body size in adulthood increased the risk of having insomnia and a morning chronotype. Conclusions: The findings suggest that higher body size in childhood is not a risk factor for later life insomnia, whereas higher body size in adulthood was. Further, if healthy body size is maintained in adulthood, high childhood adiposity may decrease the risk of insomnia and increase the risk of being a morning person in later life. Keywords: childhood, adulthood, obesity, insomnia, morning chronotype, medelian randomization

Background: Complementary and Alternative Medicine (CAM) therapies, such as massage, meditation, and yoga, are widely used to promote wellness, including sleep improvement. Although some CAM therapies may improve sleep through stress reduction, relaxation, and relief of physical discomfort, little is known about associations between individual CAM modalities and sleep health at the population level. Therefore, we investigated the associations between CAM therapies and short sleep duration as well as insomnia symptoms. Methods: Participants from the nationally-representative 2012 National Health Interview Survey (NHIS) self-reported the use of CAM therapies and short sleep duration (<7 hours vs. 7-9 hours) as well as insomnia symptoms (yes vs. no). Poisson regression with robust variance was used to estimate adjusted prevalence ratios (aPRs) and 95% confidence intervals (CIs) for cross-sectional associations between CAM therapy use and sleep outcomes. Results: Among 30,405 participants, the average age was 46.1 +/- 0.2 years and 51% were women. Adults reporting any vs. no CAM therapy use had a higher prevalence of short sleep duration (aPR: 1.11; 95% CI: 1.05-1.16) and insomnia symptoms (aPR: 1.56; 95% CI: 1.47-1.65) after adjustment for sociodemographic and clinical characteristics. Herbal supplements (aPR: 1.13; 95% CI: 1.07-1.19) and massage (aPR: 1.14; 95% CI: 1.05-1.23) were associated with higher prevalence of short sleep duration. Most CAM therapies were associated with higher prevalence of insomnia symptoms, with the strongest associations observed for meditation/guided imagery/progressive relaxation (aPR: 1.84; 95% CI: 1.68-2.02). Conclusion: The higher prevalence of short sleep duration and insomnia symptoms among CAM users may reflect reverse causation, as adults with more severe or persistent sleep disturbances may be more likely to seek CAM therapies. Longitudinal studies are needed to clarify directionality.

This study investigated bidirectional associations between maternal sleep and depressive symptoms from preconception to postpartum, and whether infant sleep mediated or moderated these associations. We used data from the Generation R Next Study (N=2,294). Maternal sleep (specifically general sleep disturbance, latency, quality, duration, and midpoint) and depressive symptoms were prospectively assessed at five timepoints from preconception to 12-month postpartum. Sleep was self-assessed with the General Sleep Disturbance Scale and Munich Chronotype Questionnaire; depressive symptoms with the Adult Self Report depression/anxiety subscale and Edinburgh Postnatal Depression Scale. Infant sleep (specifically night awakenings, nocturnal sleep duration, and latency) was parent-reported at 1-month postpartum using the Brief Infant Sleep Questionnaire. Bidirectional associations were examined using Autoregressive Latent Trajectory Models with Structured Residuals. The role of infant sleep was examined using mediation and moderation analyses. We found that maternal sleep and depressive symptoms were both stable over time. For sleep quality and disturbance, bidirectional associations suggested slightly stronger effects from depression to sleep (sleep quality:{beta}depression[-&gt;]sleep quality=0.11, 95%CI:0.07 - 0.14; general sleep disturbance:{beta}depression[-&gt;]sleep disturbance=0.14, 95%CI:0.10 - 0.18) than from sleep to depression ({beta}sleep quality/disturbance[-&gt;]depression=0.07 for both, 95%CIs:0.03 - 0.11). For latency, effects were comparable in both directions ({beta}depression[-&gt;]sleep latency=0.06, 95%CI:0.03 - 0.09; {beta}sleep latency[-&gt;]depression=0.05, 95%CI:0.01 - 0.09). The association between depressive symptoms and sleep latency was both mediated (9.7%) and moderated (p<0.05) by infant sleep latency. In conclusion, general maternal sleep disturbance, sleep quality, and sleep latency showed bidirectional associations with depressive symptoms from preconception/early pregnancy onwards. Infant sleep latency may represent a potential modifiable factor within this cycle.

BACKGROUND Safe and effective antidepressant deprescribing strategies are needed in general practice where most antidepressant prescribing occurs. METHODS We conducted a pragmatic, cluster-randomised controlled trial in general practice to test invitation to general practitioner (GP) review combined with resources to inform shared decision-making and guide hyperbolic tapering for stopping antidepressants compared to usual care. Adults taking antidepressants for longer than 12 months were recruited from 26 Australian GP practices between March 2023 and November 2024, irrespective of their intention to stop or depression or anxiety symptom scores. The primary outcome was cessation at 12 months. Secondary outcomes included cessation at 6 months, and >75% dose reduction and depression, anxiety and withdrawal symptom scores at 6 and 12 months. RESULTS Overall, 483 patients were randomised. Mean age was 50 years; 73% were women; mean duration of antidepressant use was 14.1 years. Cessation at 12 months was observed in 32 of 215 (14.9%) intervention and 16 of 187 (8.6%) usual care patients (odds ratio (OR) = 1.95 [95%CI, 1.00 to 3.81]; p=0.050). Cessation at 6 months was observed in 11.7% intervention vs 4.8% usual care (OR = 2.68; 95%CI, 1.18 to 6.05), and >75% dose reduction at 12 months in 19.6% intervention vs 9.9% usual care (OR = 2.28; 95%CI, 1.20 to 4.31). Symptom scores were similar between groups. No adverse events were attributable to the intervention. CONCLUSIONS In general practice, invitation to GP antidepressant review combined with information and guidance on hyperbolic tapering can support cessation or dose reduction without causing adverse effects or relapse. Absolute cessation rates were modest but still meaningful given the high prevalence of long term antidepressant use. TRIAL REGISTRATION ANZCT registry identifier, ACTRN12622001379707p.

In characterizing sleep and circadian health, the day-to-day regularity of sleep-wake timing strongly predicts health outcomes, outperforming short sleep duration in prospective associations with mortality and new-onset disease. It is unknown whether biological (e.g., sleep and circadian physiology) and sociocultural (e.g., exposures that affect sleep-wake timing) sex differences lead to differences in day-to-day sleep-wake regularity or modify its prospective associations with health outcomes. Here, we present findings from a UK Biobank study of 506,582 person-days of accelerometer recordings across 73,647 middle-aged adults preceding 549,009 person-years of follow-up. We compared SRI scores between males and females and evaluated whether all-cause, cardiovascular, and cancer mortality differed across SRI groups by sex. Custom contrasts were used to compare estimated marginal means across specific SRI-sex combinations. Females were overrepresented among very high (SRI [&ge;]90) and underrepresented among very low (SRI <60) groups. After adjustment for demographic, health, and behavioral covariates, males still had higher odds than females of exhibiting SRI <60. Low SRI and male sex were synergistically associated with higher mortality rate. Demographic, health, and behavioral covariate-adjusted models showed stronger and more dose-dependent associations between low SRI and mortality among males than females. Although the omnibus SRI x sex interaction terms were not statistically significant, the interaction contrast for SRI <60 versus [&ge;]90 differed by sex, suggesting a possible sex difference in mortality rates at very low SRI. Together, our findings suggest that males may be more vulnerable than females to the mortality risk associated with highly irregular sleep-wake schedules.

Insomnia is a transdiagnostic risk factor for depression and anxiety and frequently co-occurs with both conditions. Sleep restriction therapy (SRT) is considered a key active component of cognitive behavioural therapy for insomnia (CBT-I), is now delivered without therapist involvement via digital platforms such as SleepFix. Existing meta-analytic evidence suggests that digital behavioural therapy for insomnia (dBT-I) may improve anxiety and depression, but participant-level evidence remains limited. This individual participant data meta-analysis pooled data from two Australian randomised controlled trials (dBT-I n=220; control n=270; 78.3% female; mean age 66.0 years) to examine whether dBT-I, with SRT as the central component and delivered through the SleepFix program, reduces depressive and anxiety symptoms in adults with insomnia disorder, who were not specifically selected for anxiety and depression. We measured anxiety using the Generalised Anxiety Disorder 7-item scale and depression using the Patient Health Questionnaire-9 or Geriatric Depression Scale-15, with depression scores standardised to a common scale assuming a shared standard deviation of 4. We fitted linear mixed-effects models with random intercepts for participants and trials at Weeks 8 and 16, including baseline GAD-7 (mean 6.1, SD 4.8) in the anxiety model. dBT-I significantly reduced anxiety at Week 8 (mean difference -0.94 GAD-7 points, 95% CI -1.80 to -0.09, p=.030) and Week 16 (-0.94 GAD-7 points, 95% CI -1.86 to -0.02, p=.044), and depression at Week 8 (-0.40 SDs, 95% CI -0.66 to -0.14, p=.003) and Week 16 (-0.44 SDs, 95% CI -0.72 to -0.17, p=.002), with no evidence effects diminished between timepoints. However, the reductions were less than the smallest detectable difference for these questionnaires (i.e., 1 point). These findings support dBT-I as a scalable intervention with modest mental health benefits extending beyond insomnia.

INTRODUCTIONSex differences in mental health emerge during adolescence, a period marked by the onset and the establishment of menstrual cycle. However, is rarely examined how menstrual cycle regularity, a marker of hormonal function, modulates mental health. OBJECTIVEto analyse sex differences in mental health symptoms among adolescents considering the menstrual cycle regularity and sleep. METHODSA three-group design (female students with regular cycles/FR, n=77; with irregular cycles/FI, n=59; and male students/M, n=76) in a sample of Brazilian high-school adolescents (n=212; 14-18 years) enrolled in morning and full-time classes was used to test the hypothesis that mental health symptoms follow a graded pattern across these groups. RESULTSMean DASS-21 scores across all groups fell at or above the Mild severity threshold for mental health subscales. GLMs confirmed a monotonic gradient increase in group order (M[-&gt;]FR[-&gt;]FI) which was associated with higher scores on all outcomes (stress {beta}/step=4.33, p<.001; anxiety {beta}/step=4.08, p<.001; and depression {beta}/step=2.34, p=.010; model R{superscript 2}=.16, .13, .08 respectively). However, no differences were observed in sleep duration, social jetlag, chronotype, sleep quality, or sleep-debt. Then, a secondary analysis assessed sex-specific associations between socioeconomic status (SES) and mental health; higher SES was inversely related to stress, anxiety, and depression, being protective only in males (stress Males {beta}=-2.68, p=.011/Females {beta}=0.46, p=.614). CONCLUSIONThese findings support the reframing of menstrual irregularity not only as a reproductive health concern but also as a biological determinant of mental health risk in female adolescents, a vulnerability that sleep disruption and socioeconomic resources do not adequately explain.

Purpose: Comorbid restless legs syndrome (RLS) and obstructive sleep apnea (OSA) -(COROSA)- is poorly characterized in African populations. We estimated its prevalence and correlates in a population-based sample in Benin. Methods: This was a cross-sectional analysis of 1,810 adults aged [&ge;]25 years from the Benin Society and Sleep (BeSAS) study. RLS was defined by International RLS Study Group criteria and OSA by an apnea-hypopnea index [&ge;]5 events/h on home respiratory polygraphy; COROSA required both. Correlates were assessed by multivariable logistic regression; multinomial models compared COROSA with OSA only, RLS only, and neither disorder. An exploratory analysis examined hypertension across eight mutually exclusive sleep-disorder groups, including comorbid insomnia, RLS and OSA (COMIROSA). Results: COROSA prevalence was 3.5% (95% CI 2.7-4.4). Independent correlates were age 40-59 years (aOR 2.91, 95% CI 1.38-6.73), age [&ge;]60 years (aOR 3.76, 1.61-9.35), rural residence (aOR 10.54, 4.94-25.43), overweight (aOR 2.29, 95% CI: 1.16-4.49), obesity (aOR 3.83, 95% CI: 1.75-8.31), and insomnia (aOR 2.49, 1.37-4.50). Relative to OSA only, COROSA was associated with hypertension and insomnia; relative to RLS only, obesity was the main distinguishing factor. Hypertension was associated with COROSA and COMIROSA, with a larger estimate for COMIROSA (aOR 4.03 vs 2.64). Conclusion: COROSA affected 3.5% of adults in Benin and co-occurred with obesity, hypertension and insomnia. Screening for overlapping sleep disorders may improve identification of high-risk individuals. COMIROSA remains a hypothesis requiring validation in larger longitudinal studies.

Importance Anxiety of fluctuating severity is common in many psychiatric disorders. Few studies addressed factors determining individual differences in trajectories of the recovery phase, while their identification could inspire treatment innovation. Given the role of REM sleep in overnight alleviation of emotional distress, we here investigate whether individual differences in this overnight regulatory process matter for anxiety recovery. Objective To investigate whether individual differences in overnight alleviation of distress by REM sleep predict anxiety recovery rate. Design People tend to volunteer for intervention trials when fluctuating symptoms peak. This results in a significant recovery even in waitlist or control conditions. Leveraging this opportunity to recruit people prior to the recovery phase, in this cohort study, we utilized data from people who volunteered for optional sleep EEG and overnight distress assessment prior to their participation in an intervention trial (2021-2025). Anxiety severity was assessed at baseline and two months later. Setting Home-based assessment in the Netherlands. Participants Adults with insomnia alongside cross-threshold symptom severities of generalized anxiety disorder, social anxiety disorder, panic disorder, posttraumatic stress disorder, or borderline personality disorder (N = 223, 157 female [70.4%]; mean [SD] age, 45.7 [14.5] years; clinical diagnoses confirmed in 165 [74.0%]). Exposures Cognitive behavioral therapy for insomnia (CBT-I) or waitlist control. Main Outcomes and Measures Predicting 2-month anxiety improvement by individual differences in the strength of the effect of REM sleep on overnight distress alleviation at baseline. Results Within-subject mixed model analysis showed stronger overnight distress alleviation across nights with longer REM sleep (b = -0.011; 95% CI, -0.016 to -0.007; P < .001). Individual differences in the strength of REM-related distress alleviation predicted anxiety improvement after two months (b = -0.521; 95% CI, -0.854 to -0.188; P = .002), irrespective of treatment or waitlist control (interaction b = 0.011; 95% CI, -0.656 to 0.678; P = .97). Conclusions and Relevance Individual differences in the degree to which REM sleep drives overnight alleviation of distress predict the trajectory of anxiety recovery in people with clinically relevant psychiatric complaints. These findings suggest REM-related emotion regulation as a mechanism linking sleep physiology to anxiety recovery.

Sleep oscillations during non-rapid eye movement (NREM) sleep support memory consolidation but decline with age. Phase-locked auditory stimulation (PLAS) enhances slow-wave activity, yet its effects on distinct oscillatory components and memory in older adults remain unclear. Sixteen healthy older adults (60 years or older; mean age = 65.06 +/- 3.53 years) participated in a randomized, single-blind, sham-controlled crossover study. Participants completed two stimulation nights and two sham nights in a sleep laboratory. Changes in slow oscillations (0.5-1.25 Hz), frontal theta (4-8 Hz), centrofrontal slow spindles (12-14 Hz), and centroparietal fast spindles (14-16 Hz) were compared between stimulation and sham conditions. Declarative memory was assessed using a word-pair recall task that required overnight retention, and broader cognitive performance was evaluated using the Creyos cognitive assessment battery. PLAS enhanced sleep oscillatory activity without altering sleep architecture. Compared with sham, stimulation increased slow oscillation, frontal theta, centrofrontal slow spindle, and centroparietal fast spindle power across both stimulation nights. Although word-pair recall did not improve at the group level, individual differences in stimulation-induced increases in fast spindle power were positively associated with individual differences in overnight memory improvement. Closed-loop auditory stimulation enhances multiple NREM oscillations in healthy older adults while preserving sleep architecture. Moreover, stimulation-induced increases in fast spindle activity track individual differences in overnight memory improvement, suggesting fast spindles as a physiological marker of successful sleep-dependent memory consolidation and a potential target for sleep-based neuromodulation in aging.

The development of the sleep-wake cycle reflects the progressive structural and functional maturation of the brain. However, the organization of neural dynamics during prematurity remains incompletely understood. In this study, we analyzed the EEG from 54 polysomnographic recordings obtained from 39 preterm infants, grouped according to postmenstrual age (PMA) into three categories: 30-31, 32-33 and 34-35 weeks. Lempel-Ziv Complexity (LZC) and Joint Lempel-Ziv Complexity (JLZC) of the electroencephalogram (EEG) were analyzed during active sleep (AS), quiet sleep (QS), and indeterminate sleep (IS). LZC computed from the raw, unfiltered recordings were significantly higher during QS than during AS and increased with PMA during AS. To further refine the analysis, LZC was also evaluated separately in the low-frequency (1-15.5 Hz) and high-frequency (16-30 Hz) EEG bands. In the low-frequency band, LZC was consistently higher during QS than during AS, an effect that was most pronounced in more immature groups. Furthermore, LZC increased with maturation particularly during AS. Sleep-state comparisons of LZC in the high-frequency EEG band also revealed higher values during QS than during AS across all PMA groups. Moreover, in contrast to the low-frequency band, LZC progressively decreased with advancing PMA both in AS and QS, suggesting that the neural mechanisms underlying low- and high-frequency EEG activity follow distinct maturational trajectories. Interestingly, larger LZC in the temporal cortex and interhemispheric differences were detected in the 32-33 PMA group. On the other hand, JLZC analysis revealed greater joint spatiotemporal dynamics across EEG channels during QS than during AS, with consistently higher JLZC values in temporal regions and lower in occipital regions. Together, these findings show that these complexity metrics distinguishes sleep states and captures maturational changes in EEG activity in preterm infants. These results provide novel insights into early brain development and suggest potential quantitative biomarkers of neonatal brain maturation.

Background and Objectives: In persons with epilepsy, seizure risk is tightly linked to the health of sleep and circadian rhythms. Rest-activity rhythms (RARs), derived from continuously worn activity monitors, can provide objective assessments of diurnal patterns of activity. Compared with healthy controls, adults with epilepsy have been shown to display weak and unstable RARs. In this study, we aimed to directly measure RARs in patients with infantile epileptic spasms syndrome (IESS), a potentially devastating developmental and epileptic encephalopathy. As a comparator, we similarly examined identically measured RARs from a cohort of healthy infants. Methods: For this cross-sectional case-control comparison, we obtained multiday actograms in a sample of infants with IESS using ankle-worn Actiwatch-2 devices deployed during overnight follow-up EEG evaluations designed to assess initial treatment efficacy. Control actograms (similarly obtained via Actiwatch-2 devices) from the Rise & SHINE study (Sleep Health in Infancy and Early Childhood) were downloaded from the National Sleep Research Resource. We computed a series of parametric and non-parametric measures to depict the maturation of RARs over this developmental window and compared RARs from each IESS subject against up to 4 age-matched controls. Results: In 891 actigraphy recordings obtained from 333 SHINE subjects, age-dependent increases in body length and weight were associated with progressive increases in RAR height (amplitude/mesor/M10), regularity (interdaily stability), entropy and fractal complexity, together with progressive declines in RAR fragmentation (intradaily variability). Compared with age-matched controls, multiday actograms from IESS subjects (n = 11, 9 males) displayed marked reductions in RAR height (amplitude/mesor/M10) and interdaily stability, together with reductions in entropy and fractal complexity. Conclusions: During infancy, rest-activity rhythms display a stereotyped maturation in height, complexity and day to day consistency, revealing a developmental "growth curve" of RAR maturation. Severe RAR disruptions in infants with IESS may relate to the encephalopathy imposed by the underlying genetic/metabolic condition, structural lesion, and/or the psychomotor retardation imparted by antiseizure medications. Actigraphy recordings may offer a scalable, noninvasive approach to objectively and longitudinally assess circadian health in patients with IESS.

Sleep health reflects interacting demographic, clinical, micro- and macroarchitectural, and neurophysiological factors that may not be captured by single metrics or diagnostic categories. We applied hierarchical clustering to longitudinal Sleep Heart Health Study data from 1,468 adults with complete polysomnographic, demographic/clinical, and pre-sleep electroencephalographic data at two visits separated by 5.19 {+/-} 0.27 years. Forty nonredundant features selected from candidate demographic/clinical, sleep-stage, and pre-sleep spectral measures were clustered independently at each visit. Four reproducible sleep-health phenotypes emerged: a group with preserved deep sleep and favorable mental-health ratings; a large light-sleep group with low N3 and high N1; an older, physically unhealthy group with shorter total and rapid-eye-movement sleep; and a younger, physically healthy group with longer total and rapid-eye-movement sleep. The same population-level structure was evident at both visits, although only 37.7% of participants retained the same cluster assignment, with transitions most directed toward the light-sleep phenotype. An independent analysis of slow-wave morphology, excluded from cluster construction, differentiated all four phenotypes after false-discovery-rate correction. Groups with preserved or healthier sleep showed more numerous, higher-amplitude, steeper, and shorter slow waves, whereas the light-sleep and physically unhealthy groups showed weaker and more prolonged slow waves. Pre-sleep spectral features did not differ significantly across clusters after correction. These findings identify reproducible but individually dynamic sleep-health phenotypes and demonstrate that macro-architectural cluster structure is reflected in independent measures of NREM sleep microarchitecture.