Back

SLEEP

Oxford University Press (OUP)

Preprints posted in the last 30 days, ranked by how well they match SLEEP's content profile, based on 28 papers previously published here. The average preprint has a 0.02% match score for this journal, so anything above that is already an above-average fit.

1
Are infraslow oscillations the missing link between sleep and Alzheimer's?

Grollero, D.; Gabb, V.; Blackman, J.; de Vivo, L.; Coulthard, E.; Bellesi, M.

2026-04-13 neuroscience 10.64898/2026.04.09.717425 medRxiv
Top 0.1%
18.4%
Show abstract

INTRODUCTIONLocus coeruleus and glymphatic dysfunction are linked both to Alzheimers disease (AD) and, recently, to infraslow oscillation in sleep spindle (sigma) activity (ISO). Here we hypothesise ISO integrity is a critical link between sleep and AD. METHODSWe analyzed non-rapid eye movement sleep EEG from AD and controls, extracting ISO peak amplitude, intrinsic frequency, and bandwidth from the sigma-power time course. We assessed group differences and correlations with plasma biomarkers (A{beta}42/40, pTau181 and 217, NfL, GFAP). RESULTSISO peak amplitude was significantly reduced in AD, while intrinsic frequency and bandwidth were preserved. ISO peak amplitude positively correlated with A{beta}42/40 ratio, and ISO bandwidth correlated with GFAP and NfL levels, and with lower verbal memory retention. DISCUSSIONSuch selective weakening of ISO in AD is consistent with LC dysfunction and impaired glymphatic cycling. ISO may be a novel mechanism and electrophysiological marker linking sleep microarchitecture to AD pathology.

2
Targeted memory reactivation during sleep modulates spindle and slow wave density, but not motor memory consolidation, in Parkinson's disease

Micca, L.; Albouy, G.; King, B. R.; Nieuwboer, A.; Vandenberghe, W.; Borzee, P.; Buyse, B.; Testelman, D.; Nicolas, J.; Gilat, M.

2026-04-27 neurology 10.64898/2026.04.22.26351552 medRxiv
Top 0.1%
12.9%
Show abstract

Motor memory retention is impaired in Parkinson's disease (PD), affecting long-term rehabilitation outcomes. It appears that NREM sleep could be beneficial for consolidation processes in PD, and could be leveraged with non-invasive sleep interventions. This study examined the effect of auditory targeted memory reactivation (TMR) during NREM sleep on the retention of a motor sequence learning finger tapping task in 20 PD and 20 healthy older adults (HOA). TMR was applied during a 2-hour nap and its effect on motor retention was post-nap, after 24-hours and with a dual-task. The impact of TMR on sleep electrophysiology was also evaluated. Results showed no effect of TMR on motor retention or dual-tasking, with no difference between the groups. However, the TMR intervention did increase slow-wave density and decreased spindle density in both groups, and slow-wave amplitude during the presentation of the auditory cues was positively associated with performance in HOA. In conclusion, TMR applied during a 2 hour nap did not enhance motor retention, but the changes in sleep physiological features could be linked to a possible underlying effect on memory processing that warrants further investigation.

3
Sex moderates apolipoprotein E ε4 effects on sleep expression and memory retention

Sattari Barabadi, N.; Dave, A.; Chen, I. Y.; Kui, K. K.; Chappel-Farley, M. G.; Berisha, D. E.; Sprecher, K. E.; Riedner, b. A.; Jones, S.; Bendlin, B. B.; Mander, B. A.; Benca, R. M.

2026-04-18 pathology 10.64898/2026.04.16.26351049 medRxiv
Top 0.1%
6.4%
Show abstract

Introduction: Sleep-dependent memory consolidation differs by sex and maybe disrupted by Alzheimer disease (AD) risk. Whether sex moderates associations between apolipoprotein E {varepsilon}4(APOE {varepsilon}4) status, non-rapid eye movement (NREM) sleep, and memory remains unclear. Methods: Eighty cognitively unimpaired older adults completed a word-pair memory task with encoding and immediate testing occurring prior to overnight polysomnography with high-density electroencephalography (hdEEG) and delayed recall occurring after sleep. Sleep-memory associations were examined as a function of sex and APOE {varepsilon}4 status. Results: In this sample, a sex by APOE {varepsilon}4 interaction was associated with overnight memory retention, with female carriers exhibiting less overnight forgetting than female non-carriers and male {varepsilon}4 carriers. NREM sleep differed by sex and APOE {varepsilon}4 status and was associated with memory retention in {varepsilon}4 carriers. Discussion: These findings indicate sex-specific, sleep-dependent memory mechanisms associated with genetic AD risk, highlighting sleep as a potential early target for intervention, pending replication in larger samples. This study was not a clinical trial.

4
Narcolepsy is associated with cardiovascular burden

Ollila, H. M.; Eghtedarian, R.; Haapaniemi, H.; Ramste, M.; FinnGen,

2026-04-23 epidemiology 10.64898/2026.04.22.26351468 medRxiv
Top 0.1%
6.4%
Show abstract

Background: Narcolepsy is a debilitating sleep disorder caused by hypocretin deficiency. Aside from its role to induce wakefulness, hypocretin is linked to modulated appetite and metabolism, often resulting in weight gain. Study objectives: We aimed to unravel the comprehensive epidemiological connection between narcolepsy and major cardiometabolic outcomes. Methods: We analyzed cardiovascular and metabolic disease distribution in the FinnGen study. Using longitudinal electronic health records, we assessed associations between narcolepsy, cardiac/metabolic markers, and prescriptions for relevant drugs. Results: Our findings demonstrate significant associations between narcolepsy and metabolic traits (OR [95% CI] = 2.65 [1.81, 3.89]) as well as stroke (OR = 2.36 [1.38, 4.04]). Narcolepsy patients exhibit a less favourable metabolic profile, including higher glucose levels (OR = 1.1143 [1.0599, 1.1715]) and dyslipidaemia. This is supported by increased prescriptions of insulin (OR = 2.269 [1.46, 3.53]), simvastatin (OR = 2.292 [1.59, 3.31]), and metformin (OR = 2.327 [1.66, 3.25]), reflecting high metabolic disturbances. Furthermore, positive associations with antihypertensive and antiplatelet medications were observed, consistent with elevated cardiovascular risk. Conclusion: Taken together, our findings highlight the cardiometabolic burden in narcolepsy. This study enhances understanding of the metabolic and cardiovascular consequences of narcolepsy and offers timely guidance for effective disease control.

5
Sleep and emotional memory: translating neural response at encoding to memory accuracy in men and women with and without PTSD

Santistevan, A. C.; Natraj, N.; Yack, L. M.; Felmingham, K. L.; Woodward, S. H.; Mathalon, D. H.; Neylan, T. C.; Richards, A.

2026-03-31 neuroscience 10.64898/2026.03.27.714805 medRxiv
Top 0.1%
6.4%
Show abstract

BackgroundGrowing evidence suggests that sleep plays an important role in PTSD outcomes, potentially due to its influence on emotional memory consolidation, though these mechanisms remain unknown. This study sought to test the hypotheses that sleep neurophysiology, PTSD status, and sex moderates the degree to which the late positive potential (LPP) mediates memory accuracy for affective visual stimuli. MethodsN = 39 participants (18 female) viewed 75 negative and 75 neutral IAPS images while EEG was recorded. After viewing the images, participants took a two-hour long nap which was followed by a memory assessment. Memory accuracy was measured using d = Z(hit rate) - Z(false alarm rate), where hit rate refers to the proportion of images seen during the memory assessment that are correctly identified as being previously seen, false alarm rate refers to the proportion of images seen during the memory assessment that are incorrectly identified as being previously seen, and Z() is the inverse cumulative distribution function of the standard normal distribution function. ResultsThe early (300 - 1000 ms) and late (1000 - 1500 ms) LPP mediated enhanced discrimination accuracy for emotional compared to neural stimuli (d) (ps < 0.001). The association between the late LPP and d was moderated by sleep such that the association was stronger when participants spent proportionately more time in N3 and REM (p = 0.02). The differences in reactivity between emotional and neutral images for both the early and late LPP were attenuated in PTSD+ individuals vs. controls (ps < 0.001). Despite mediation results showing greater d for emotional compared to neutral stimuli, women showed overall worse memory accuracy for negative compared to neutral stimuli (p < 0.001) whereas men showed no difference (p = 0.64). ConclusionsN3 and REM sleep play a critical role for memory of stimuli that produce large and sustained neural responses. PTSD is marked by a diminished ability to distinguish between negative and neutral information. More research is critical to understand sex effects on emotional memory.

6
Obstructive Sleep Apnea is Associated with Peri-Lead Edema Following Deep Brain Stimulation for Parkinson's Disease

Kornilov, E.; Alkan, U.; Harari, E.; Azem, K.; Fireman, S.; Kahana, E.; Reiner, J.; Sapirstein, E.; Sela, G.; Glik, A.; Fein, S.; Tamir, I.

2026-04-06 neurology 10.64898/2026.04.05.26350193 medRxiv
Top 0.1%
6.1%
Show abstract

Background: Peri-lead edema (PLE) occurs in up to 15% of Deep Brain Stimulation (DBS) cases, can cause morbidity, and its etiology remains unknown. We hypothesized that PLE represents a secondary brain injury modulated by hypoxemia, and that patients with obstructive sleep apnea (OSA) are at elevated risk. Methods: We conducted a retrospective case-control study of 121 Parkinson's disease (PD) patients undergoing DBS at a single center (2019-2024). PLE severity was quantified by CT volumetric segmentation and Hounsfield unit (HU) measures. Perioperative SpO2 and PaO2 were recorded. Polysomnography (PSG) was available in 26 patients; and the REM Sleep Behavior Disorder Screening Questionnaire (RBDSQ) was administered retrospectively. Results: Symptomatic PLE occurred in 12 patients (9.9%), with onset at 3.5 (2-9) days postoperatively. PLE patients had higher body mass index (p = 0.022) and higher OSA prevalence (75% vs. 30%; p = 0.002). Perioperative SpO2 was lower in the PLE group in both the operating room and post-anesthesia care unit (PACU; p < 0.05); PaO2 was lower in the PACU (p = 0.037). In the PSG subgroup, REM Sleep Behavior Disorder (RBD) incidence was lower in PLE patients (20% vs. 60%; unadjusted p = 0.048), and PLE severity correlated significantly with sleep-related hypoxemia and respiratory indices. RBDSQ scores were positively associated with edema density (normalized HU: rho = 0.86, p = 0.024). Conclusions: OSA and perioperative hypoxemia are associated with symptomatic PLE following DBS, while RBD appears protective. Preoperative sleep evaluation and optimized perioperative airway management warrant prospective investigation as PLE prevention strategies.

7
Chronic short sleep in early life accelerates cognitive decline via disrupted proteostasis

Komlo, R.; Sengupta, K.; Strus, E.; Naidoo, N.

2026-03-30 neuroscience 10.64898/2026.03.26.714554 medRxiv
Top 0.1%
4.9%
Show abstract

Chronic short sleep (CSS) is an emerging public health issue that frequently begins in adolescence and is common among healthcare professionals and others engaged in shift work. Epidemiological studies associate CSS and sleep disruption with metabolic disorders, cardiovascular disease, cognitive decline, and heightened Alzheimers disease risk. Building on our prior findings that sleep deprivation perturbs proteostasis and activates endoplasmic reticulum (ER) stress pathways, we investigated the long-term consequences of CSS in young adult wild-type mice over the course of one year. Mice exposed to CSS displayed impaired cognition in hippocampal dependent tasks by 28 weeks of age, indicating emerging memory deficits. At the molecular level, CSS disrupted hippocampal proteostasis--particularly protein folding processes--and triggered ER stress and activation of the unfolded protein response (UPR). Importantly, disrupted proteostasis preceded the behavioral decline, with diminution of the key chaperone and UPR regulator BiP occurring at 20-22 weeks of age. CSS also increased markers of cellular stress and neuroinflammation while reducing the expression of proteins associated with memory function. Age also seemed to be a cellular stressor, causing a longitudinal increase in UPR, ISR, and neuroinflammation markers. Together, these results indicate that both chronic short sleep and age compromise proteostasis and promote neuroinflammation, contributing to progressive cognitive dysfunction.

8
Bidirectional restoration of sleep homeostasis in neurodegeneration via closed-loop auditory stimulation

Dias, I.; Zust, M.; Baumann, C. R.; Noain, D.

2026-04-15 neuroscience 10.64898/2026.04.13.718146 medRxiv
Top 0.1%
4.0%
Show abstract

Sleep-wake disturbances in Alzheimers (AD) and Parkinsons disease (PD) are linked to disrupted slow-wave activity (SWA) and SW-spindle coupling, critical for memory consolidation and protein clearance. While SWA enhancement shows promise in aging, disease-specific effects on SW synchronization (local, linked to sleep depth vs. global, linked to arousal), spindle dynamics and sleep homeostasis remain unexplored in neurodegeneration. Using mouse closed-loop auditory stimulation (mCLAS), we probed its acute effects on SW subtypes, spindle characteristics, SW-spindle coupling and sleep homeostasis in Tg2576 (AD) and M83 (PD) mice. mCLAS adaptively modulates SW subtypes and SW-spindle coupling depending on baseline impairments. In AD mice, it reduces global synchrony while potentiating local phenomena and network recruitment, restoring SW-spindle coupling strength and normalizing spindle power. In PD mice, mCLAS increases global synchrony, reorganizing 24-hour SW dynamics towards wild-type patterns, while reducing excessive SW-spindle coupling and enhancing spindle power. Critically, mCLAS bidirectionally regulates sleep homeostasis: boosting deficient slow-wave energy in AD and reducing excess in PD to restore physiological sleep. These findings suggest mCLAS acts via complementary mechanisms to rescue sleep homeostasis in neurodegeneration, by modulating cortical synchrony in AD and arousal in PD, offering a noninvasive path to potentially mitigate cognitive decline and pathological progression.

9
Nocturnal and Diurnal Measures of Autonomic Function in Idiopathic Hypersomnia and Type 1 Narcolepsy

Zitser, J.; Baldelli, L.; Taha, H. B.; Sibal, O.; Chiaro, G.; Cecere, A.; Barletta, G.; Cortelli, P.; Guaraldi, P.; Miglis, M. G.

2026-04-13 neurology 10.64898/2026.04.09.26349889 medRxiv
Top 0.1%
3.6%
Show abstract

Study ObjectivesIdiopathic hypersomnia (IH) is a central nervous system hypersomnia frequently accompanied by autonomic symptoms, yet objective physiological data are limited. We sought to characterize autonomic nervous system (ANS) dysfunction in IH using nocturnal heart rate variability (HRV) and diurnal autonomic reflex testing (ART), compared to individuals with type 1 narcolepsy (NT1) and healthy controls (HCs). MethodsTwenty-four adults with IH, 10 with NT1, and 14 HCs underwent overnight video polysomnography with HRV analyses in time and frequency domains during stable slow-wave sleep and REM sleep. Comprehensive ART included sympathetic adrenergic (head-up tilt (HUT), Valsalva BP responses), parasympathetic cardiovagal (HRV to deep breathing, Valsalva ratio), and sudomotor (Q-Sweat) measures. ResultsIH participants were predominantly female, with over half reporting long sleep duration. Compared to NT1 and HC, participants with IH demonstrated a greater magnitude of orthostatic tachycardia on tilt ({Delta}HR 41.0 {+/-} 16.3 vs. 26.3 {+/-} 9.3 vs. 30.8 {+/-} 9.3 bpm, p = 0.0086), as well as frequent sudomotor dysfunction (64.3%). IH participants demonstrated greater nocturnal and REM HR with reduced parasympathetic indices during REM, indicating diminished vagal modulation compared with HCs ConclusionsIH is characterized by a distinct pattern of autonomic dysfunction, including pronounced orthostatic tachycardia, frequent sudomotor abnormalities, and reduced parasympathetic activity during sleep. These findings provide objective physiological evidence of ANS involvement in IH and delineate features that distinguish IH from NT1 and HCs.

10
Public involvement and co-design of longitudinal studies of sleep health alongside young people with rare genetic conditions

Clayton, J. P.; Haddon, J. E.; Hall, J.; Attwood, M.; Jarrold, C.; Berndt, L. C. S.; Saka, A.; van den Bree, M. B. M.; Jones, M. W.; Collaboration: Sleep Detectives Lived Experience Advisory Panel,

2026-04-13 psychiatry and clinical psychology 10.64898/2026.04.07.26348880 medRxiv
Top 0.2%
2.1%
Show abstract

BackgroundThe mechanisms underpinning associations between sleep and psychiatric conditions are poorly understood, partly due to challenges with longitudinal sleep studies outside the laboratory. Children and young people with rare genetic conditions caused by micro-deletions or -duplications (Copy Number Variants or CNVs) have increased risk of disrupted sleep and poorer neurodevelopmental (ND) outcomes. The Sleep Detectives study aims to investigate this by tracking behavioural and neurophysiological signatures of sleep health in young people with ND risk or ND-CNVs. To optimally achieve this, we have worked with families with ND-CNVs and charity partners to co-design our tools, methods, study protocol, and materials. MethodWe established a Lived Experience Advisory Group (LEAP) with nine parents and 13 children and young people with ND-CNVs, alongside representatives of UK charities Max Appeal and Unique. Together, the research team and LEAP co-designed two in-person family workshops in which we collected feedback on the acceptability of sleep monitoring devices, the design of bespoke cognitive tasks, and overall study protocol. Informal interviews and surveys were conducted with LEAP members and researchers, to enable the team to reflect and learn from their Patient/Public Involvement (PPI) experiences. ResultsKey outputs included pre-workshop invitation and briefing materials and insights that iteratively refined the main study design, including the need for flexibility to increase accessibility, selection of sleep devices, customisation of cognitive tasks, and choice of language in documents. The PPI process was highly valued by LEAP members, workshop attendees, and the research team. One investigator described the PPI work as "reinvigorating my love of research by helping me focus on science that matters". Participating families also established peer support networks. ConclusionsInvolving families affected by ND-CNVs in co-designing the Sleep Detectives study maximised opportunities for acceptability, accessibility and scalability. The research team gained inspiration and deeper understanding of the impact of ND-CNVs on families. Families gained awareness about research, established connections with each other and peer support, and were enthusiastic about future research involvement. This experience empowered families to engage more deeply with the research process and helped the PPI work to be more impactful and inclusive. Plain English summaryChildren and young people with rare genetic conditions caused by small deletion or duplication of genetic material are more likely to experience sleep difficulties such as insomnia, restless sleep, and tiredness. They also show an increased likelihood of neurodevelopmental conditions such as learning disability and autism, and mental health issues such as anxiety. The Sleep Detectives team wanted to explore how these genetic conditions affect childrens sleep, cognition and psychiatric health. To make sure that the project design was well suited to the children and young people that would be invited to participate, the team worked closely with families to design the study. Parents and caregivers of affected children and young people were invited to join a Lived Experience Advisory Panel (LEAP), together with charity representatives and Sleep Detective researchers, to co-design two hands-on workshops, and advise on study design. Children and young people and parents/caregivers attending the workshops tried out and provided feedback on tools and devices that the research team were developing. They also advised on the arrangements and support families might need whilst taking part, and on the study protocol. This collaborative approach helped ensure the study design was optimally suited for the recruitment and participation of children and young people and their families. This report documents our public involvement work for the Sleep Detectives study, illustrating the difference the partnership between researchers and families has made to the project, and the wider benefits for all concerned.

11
Lack of Consensus for Manual Mouse Sleep Scoring Limits Implementation of Automatic Deep Learning Models

Rose, L.; Zahid, A. N.; Ciudad, J. G.; Egebjerg, C.; Piilgaard, L.; Soerensen, F. L.; Andersen, M.; Radovanovic, T.; Tsopanidou, A.; Nedergaard, M.; Arthaud, S.; Maciel, R.; Peyron, C.; Berteotti, C.; Martiere, V. L.; Silvani, A.; Zoccoli, G.; Borsa, M.; Adamantidis, A.; Moerup, M.; Kornum, B. R.

2026-03-30 neuroscience 10.64898/2026.03.27.714381 medRxiv
Top 0.2%
2.1%
Show abstract

Scientists have for decades attempted to automate the manual sleep staging problem not only for human polysomnography data but also for rodent data. No model has, however, succeeded in fully replacing the manual procedure across clinics and laboratories. We hypothesize that this is due to the models limited ability to generalize to data from unseen laboratories. Our findings show that despite the high performance of four state-of-the-art models reported in initial publications, the published models struggle to generalize to other laboratories. We further show a significant improvement in model performance across labs by re-training them on a diverse dataset from five different sites. To assess the contribution of variability in manual scoring, ten experts from five laboratories all labelled the same nine mouse sleep recordings. The result revealed substantial scoring variability, particularly for rapid eye movement (REM) sleep, both within and between labs. In conclusion our study demonstrates that key challenges in the generalizability of state-of-the-art sleep scoring models are signal variability and label noise. Our study highlights the need for a standardized set of mouse sleep scoring guidelines to enable consistency and collaboration across the field. Until such a consensus is reached, we present four sufficiently robust models trained on diverse datasets that can serve as standardized tools across labs.

12
The impact of age, comorbidity, and current medication use on plasma p-tau217 in adolescents

Stancil, S. L.; Brewe, M.; Mayfield, H.; Morris, J.

2026-03-31 pediatrics 10.64898/2026.03.30.26349647 medRxiv
Top 0.2%
1.8%
Show abstract

Background: Adolescence is a critical period of neurodevelopment with the emergence of chronic medical conditions and increasing exposure to long-term medications. P-tau217 is a sensitive blood-based biomarker of neuropathology in older adults, yet its developmental behavior and susceptibility to common clinical factors in youth are unclear. Here we tested whether p-tau217 varies with age, comorbidity, or medication use during adolescence; and whether collection method (venous vs Tasso+ capillary) yields comparable concentrations. Methods: In an adolescent cohort, plasma p-tau217 was measured by Simoa-X. Paired venous and Tasso+ capillary samples were also analyzed from adult volunteers for methodological comparison Results: In adolescents (n=41; mean age 16{+/-}2.6 years), p-tau217 did not correlate with age or BMI z-score and did not differ by psychiatric, cardiometabolic, or gastrointestinal comorbidity, nor by corresponding medication use. In contrast, p-tau217 concentrations were >10-fold higher in Tasso+ capillary plasma than venous plasma, a discordance replicated in paired adult samples. Conclusion: Plasma p-tau217 appears physiologically stable across common clinical variables in adolescence, but highly sensitive to biospecimen collection method. Venous and Tasso+ capillary plasma should not be directly compared or pooled until methodological differences are resolved. These data provide a developmental baseline and critical methodological caution for pediatric neuroscience and decentralized biomarker studies.

13
Sleep physiology in late pregnancy: A video-based, multi-night, in-home, level 3 sleep apnea study of pregnant participants and their bed partners

Kember, A. J.; Ritchie, L.; Zia, H.; Elangainesan, P.; Gilad, N.; Warland, J.; Taati, B.; Dolatabadi, E.; Hobson, S.

2026-04-25 obstetrics and gynecology 10.64898/2026.04.17.26351131 medRxiv
Top 0.3%
1.5%
Show abstract

We completed a video-based, four-night, in-home, level 3 sleep apnea study of healthy, low-risk pregnant participants and their bed partners in order to characterize sleep physiology in the third trimester of pregnancy. Demographic, anthropometric, and baseline sleep health characteristics were recorded, and the NightOwl home sleep apnea test device was used to measure sleep breathing, posture, and architecture parameters. Symptoms of restless legs syndrome were elicited in the exit interview. Forty-one pregnant participants and 36 bed partners completed the study. Bed partners had a significantly higher prevalence of sleep apnea than their pregnant co-sleepers (31% vs. 5.9%). Bed partners also had more severe sleep apnea than their pregnant co-sleepers, and this persisted on an adjusted analysis for baseline differences in factors known to increase risk of sleep apnea. In pregnant participants, increasing gestational age was found to be protective against mild respiratory events but not more severe events. While the correlation between STOP-Bang score and measures of sleep apnea severity was weak, an affirmative response to the witnessed apneas item on the STOP-Bang questionnaire was a strong predictor of more severe sleep apnea for all participants. Smoking history also increased sleep apnea risk. Pregnant participants had lower sleep efficiency and longer self-reported sleep onset latency. Restless legs syndrome was experienced by 39.5% of the pregnant participants but no bed partners. From a sleep breathing perspective, people with healthy, low-risk pregnancies have better sleep than their bed partners despite lower sleep efficiency and higher rates of restless legs syndrome.

14
Polysomnographic parameters in schizoaffective disorder: a systematic review and meta-analysis

Morra, D.; Ficca, G.; Barbato, G.

2026-04-06 psychiatry and clinical psychology 10.64898/2026.04.06.26350239 medRxiv
Top 0.3%
1.3%
Show abstract

A systematic review and meta-analysis of sleep studies in schizoaffective disorder were conducted using published articles researched in major databases within the period from inception to December 1, 2025. The sleep parameters: total sleep time, sleep efficiency, sleep latency, wakefulness, REM time and percentage, REM latency, REM density, stage 1, 2, 3 and 4 sleep time and percentage, delta sleep time and percentage, of drug-free schizoaffective patients were analyzed and, where available, compared with case-control data of healthy controls, depressed unipolar patients and schizophrenic patients. Forty studies were identified in the systematic review. Nine case-control studies with 67 schizoaffective patients, 88 schizophrenic patients, 79 healthy controls and 131 depressed patients were included in the meta-analyses. The primary outcome was the standard mean difference. Data were fitted with a random-effects model. Publication bias assessment was checked by Egger's Regression and funnel plot asymmetry. Patients with schizoaffective disorder showed reduced total sleep time, increased sleep latency and wakefulness, along with reduced REM time and shortened REM latency, reduced stage 4 sleep time and percentage compared to healthy controls. Patients with schizoaffective disorder differed from depressed patients only for increased sleep latency, while they did not show any difference compared to patients with schizophrenia. SZA showed a non-significant trend (p=0.08) towards increased REM density compared to SCZ, suggesting the need to better clarify the role of REM density in mood and psychotic disorders.

15
Salivary dim-light melatonin onset in early Amyotrophic Lateral Sclerosis predicts functional decline, respiratory symptom emergence, and survival

Bombaci, A.; Iadarola, A.; Giraudo, A.; Fattori, E.; Sinagra, S.; Magnino, A.; Calvo, A.; Chio', A.; Cicolin, A.

2026-04-25 neurology 10.64898/2026.04.24.26351642 medRxiv
Top 0.3%
1.2%
Show abstract

Background: Sleep wake and circadian disturbances are increasingly recognised in people living with amyotrophic lateral sclerosis (plwALS), but endogenous circadian phase timing and its prognostic significance in early disease remain unclear. We assessed whether salivary dim-light melatonin onset (DLMO), an objective marker of central circadian phase, is altered in early plwALS and whether it provides prognostic information. Methods: In this prospective longitudinal observational study, plwALS within 18 months of symptom onset underwent home-based salivary melatonin sampling under dim light conditions at six predefined time points around habitual sleep onset (HSO). Melatonin profiles were modeled using cubic smoothing splines, and DLMO was defined as the first time the fitted curve reached 3 pg/mL. Clinical, respiratory, and sleep assessments were collected at baseline (T0) and after 6 months (T6); a subgroup repeated saliva sampling at T6. Age and sex matched controls underwent melatonin profiling. Associations with disease progression, incident respiratory symptoms, and survival/tracheostomy were examined using regressions and survival analyses. Results: Fifty plwALS were enrolled. Compared with controls, plwALS showed an earlier DLMO (20:24 vs 20:58; p=0.028) despite similar HSO and chronotype. Within ALS cohort, a later baseline DLMO correlated with worse functional/motor status, faster progression of disease, incident dyspnea/orthopnea by T6 (adjusted OR 3.02; p=0.017), and poorer survival/tracheostomy-free outcome. In re-sampled subgroup (n=28), DLMO and other melatonin-derived metrics did not change over 6 months. Conclusions: Circadian phase alterations are detectable in early ALS. Baseline DLMO may represent a non-invasive prognostic biomarker for progression, respiratory symptom emergence and survival, warranting validation in larger multicentre cohorts.

16
Multidimensional Sleep Health and Cognitive Risk in Midlife Primary Care: Comparing Questionnaires

Kim, M.; Bonham, M.; Yeh, F.; Rogers, L.; Ho, E. H.; Curtis, L.; Benavente, J. Y.; Bailey, S. C.; Linder, J. A.; Wolf, M. S.; Zee, P. C.

2026-04-17 primary care research 10.64898/2026.04.15.26350952 medRxiv
Top 0.3%
1.2%
Show abstract

Importance: Sleep-wake disturbances in midlife are common and potentially modifiable contributors to long-term brain health, yet primary care lacks a brief, validated tool that reliably identifies adults with early cognitive vulnerability. Objective: To evaluate associations between commonly used sleep questionnaires and cognitive impairment among midlife primary care patients. Design, Setting, and Participants: Cross-sectional analysis of baseline data from the MidCog cohort, an observational study of English-speaking adults aged 35 to 64 years receiving primary care at academic practices or federally qualified health centers in the Chicagoland area. Exposures: Five validated sleep questionnaires were used to assess distinct sleep-wake disturbance phenotypes: (A) unsatisfactory sleep (PROMIS Sleep Disturbance T-score >55), (B) short sleep duration (<6 hours; Munich Chronotype Questionnaire), (C) obstructive sleep apnea (OSA) risk (STOP-Bang [&ge;]3), (D) insomnia symptoms (Insomnia Severity Index [&ge;]15), and (E) poor multidimensional sleep health (RU-SATED [&le;]6). Main Outcomes and Measures: The primary outcome was cognitive impairment defined as an age- and education-adjusted NIH Toolbox Cognition Battery (NIHTB-CB) Fluid Composite T-score <40 ( >1 SD below the population mean). Cognitive impairment defined by the Montreal Cognitive Assessment (MoCA) score <23 served as the secondary outcome. Logistic regression estimated adjusted odds ratios (aOR), controlling for age, sex, education, body mass index, hypertension, hypercholesterolemia, diabetes, smoking, depressive symptoms, and recruitment site. Results: Among 646 participants (mean [SD] age, 52.3 [8.1] years; 62.4% female; 38.0% non-Hispanic Black, 38.4% non-Hispanic White, 16.0% Hispanic), cognitive impairment was present in 18.7% by NIHTB-CB and 22.3% by MoCA. Among five sleep-wake disturbance phenotypes evaluated, only poor multidimensional sleep health was consistently associated with cognitive impairment after multivariable adjustment (NIHTB-CB: adjusted OR [95% CI] = 2.03 [1.25-3.26]; MoCA: 1.98 [1.20-3.26]). Conclusions and Relevance: Poor multidimensional sleep health was associated with cognitive impairment in midlife primary care patients. Brief multidimensional sleep health screening may identify individuals with early cognitive vulnerability and represent a potential strategy for targeting sleep-focused interventions to promote long-term brain health.

17
Molecular signaling associated with antidepressant actions exhibits diurnal fluctuations in the prefrontal cortex and hippocampus of adult male and female mice

Gonzalez-Hernandez, G.; Rozov, S.; Berrocoso, E.; Rantamäki, T.

2026-04-08 neuroscience 10.64898/2026.04.07.716906 medRxiv
Top 0.3%
0.9%
Show abstract

An increasing number of epidemiological and experimental studies have demonstrated a bidirectional relationship between mood disorders and the circadian system, with disrupted circadian rhythms contributing to depressive states, and their restoration playing a key role in antidepressants effects. In this context, we sought to examine whether key molecular targets of antidepressants exhibit diurnal regulatory patterns. Naive adult male and female C57BL/6 mice were euthanized at 3-hour intervals beginning at Zeitgeber Time 0 (ZT0), and hippocampal (HC) and medial prefrontal cortex (mPFC) tissues were collected for RT-qPCR and western blot analyses. We observed statistically significant diurnal rhythmicity in all analyzed transcripts (cFos, Arc, Nr4a1, Dusp1, Dusp5, and Dusp6) in both HC and mPFC samples, with peak expression occurring during the dark (active) phase (ZT15-18). Phosphorylation levels of TrkBY816 (tropomyosin-related kinase) and GSK3{beta}S9 (glycogen synthase kinase 3{beta}) also showed periodic rhythmicity, peaking during the light (inactive) phase. Levels of p-ERK2T185/Y187 (extracellular-signal regulated kinase) did not display rhythmicity, but peaked during the light phase in the HC, especially in males. Collectively, these findings demonstrate that antidepressant targets are subject to diurnal regulation, highlighting the importance of integrating circadian biology and time-of-day as relevant variables in the development of translationally relevant antidepressant research. HighlightsO_LIKey molecular targets of antidepressants exhibit diurnal regulation in adult mice C_LIO_LIDiurnal patterns were conserved across targets, sexes, and brain regions (HC&PFC) C_LIO_LIcFos, Arc, Nr4a1, Dusp1,5,6 mRNAs display peak expression during the dark phase C_LIO_LITrkBY816 and GSK3{beta}S9 phosphorylation peak during the light (inactive) phase C_LIO_LIAntidepressant mechanisms may be linked with circadian and sleep-wake dynamics C_LI Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=102 SRC="FIGDIR/small/716906v1_ufig1.gif" ALT="Figure 1"> View larger version (25K): org.highwire.dtl.DTLVardef@1e65e60org.highwire.dtl.DTLVardef@13e302corg.highwire.dtl.DTLVardef@1ccc25forg.highwire.dtl.DTLVardef@1ed10d3_HPS_FORMAT_FIGEXP M_FIG C_FIG

18
Association of Obstructive Sleep Apnea With Risk of Myocardial Infarction: A Multivariable Mendelian Randomization and Mediation Analysis

zhang, y.; ZHU, X.; chen, y.; Maimaitimin, A.; Liang, Z.; Maihemutijiang, R.; Nihimaiti, N.

2026-03-31 cardiovascular medicine 10.64898/2026.03.29.26349673 medRxiv
Top 0.4%
0.8%
Show abstract

BACKGROUND: Observational studies have suggested an association between obstructive sleep apnea (OSA) and myocardial infarction (MI), but whether this relationship is causal or largely reflects shared risk factors remains unclear. METHODS AND RESULTS: We performed a 2-sample Mendelian randomization (MR) analysis to evaluate the causal effect of OSA on MI. Summary statistics for OSA were obtained from FinnGen, and MI data were obtained from the UK Biobank, with external validation using CARDIoGRAMplusC4D. Mediation MR was used to assess 13 potential mediators, and a 6-step multivariable MR framework was applied to estimate the direct effect of OSA after sequential adjustment for potential confounders. Reverse MR was conducted to test possible reverse causality. Genetically predicted OSA liability was associated with increased MI risk (odds ratio [OR] per log-OR increase, 1.0024 [95% CI, 1.0010-1.0039]; P=0.001). Body mass index (BMI) was the strongest mediator, explaining 35.94% of the association (P=0.030), whereas systolic blood pressure (SBP) showed minimal mediation (0.28%; P=0.678). In stepwise multivariable MR, the OSA-MI association was attenuated after adjustment for BMI and SBP (P=0.156), suggesting partial confounding by shared cardiometabolic risk. In a model including SBP and atrial fibrillation (AF), AF remained independently associated with MI (P=0.004), whereas OSA showed only a marginal direct effect (P=0.050). Reverse MR found no evidence that MI influenced OSA risk. CONCLUSIONS: These findings support a causal association between OSA and MI and suggest that this relationship may be mediated in part through obesity-related and arrhythmia-related pathways. AF may represent an important intermediate component of OSA-related cardiovascular risk beyond traditional hemodynamic factors. Keywords: obstructive sleep apnea; myocardial infarction; Mendelian randomization; mediation analysis; obesity.

19
The burden of neurogenic orthostatic hypotension in patients with multiple system atrophy: a real-world study

Kmiecik, M. J.; O'Brien, L.; Szpyhulsky, M.; Iodice, V.; Freeman, R.; Jordan, J.; Biaggioni, I.; Kaufmann, H.; Vickery, R.; Miller, A.; Saunders, E.; Rushton, E.; Valle, L.; Norcliffe-Kaufmann, L.

2026-04-22 neurology 10.64898/2026.04.20.26351214 medRxiv
Top 0.4%
0.8%
Show abstract

BackgroundAlthough neurogenic orthostatic hypotension (nOH) is a common and debilitating feature of multiple system atrophy (MSA), little is known about the burden of symptoms in the real world. ObjectivesTo design and conduct a cross-sectional community-based research survey targeting patients with MSA, with and without nOH. MethodsWe recruited patients with MSA to complete an anonymous online survey covering three core themes: 1) timely diagnosis, 2) nOH pharmacotherapy and refractory symptoms, and 3) confidence in physician knowledge. Responses were grouped by pre-specified diagnostic certainty levels. Relationships between symptoms, function, and pharmacotherapy were assessed using univariate and multivariate methods. ResultsWe analyzed 259 respondents with a self-reported diagnosis of MSA (age: M=64.38, SD=8.09 years; 44% female). In total, 42% also had a diagnosis nOH; 40% had symptoms highly suspicious of nOH, but no diagnosis; and 21% reported having never had their blood pressure measured in the standing position at a clinical visit. Treatment with a pressor agent was independently associated with the presence of other symptoms of autonomic failure. Each additional nOH symptom reported increased the odds of requiring pharmacotherapy by 18%. Yet, despite anti-hypotensive medication use, 97% of patients reported limitations in their ability to bathe, cook, or arise from a chair/bed with 76% needing caregiver support for refractory nOH symptoms. ConclusionsThis cross-sectional representative sample shows nOH is underrecognized and undertreated in MSA patients, leading to substantial functional limitations. It is our hope that these findings are leveraged for planning future trials and advocating for better treatments.

20
Sleeping with One Eye Open: Lived Experiences of Informal Caregivers Regarding Nighttime Agitation in People with Dementia

Flisar, A.; Van Den Bossche, M.; Coppens, E.; Van Audenhove, C.; Dezutter, J.

2026-03-30 psychiatry and clinical psychology 10.64898/2026.03.27.26349496 medRxiv
Top 0.4%
0.8%
Show abstract

Nighttime agitation (NA) is a prevalent and challenging phenomenon affecting people with dementia (PwD), often resulting in premature institutionalization. Yet, informal caregivers' perspectives on this phenomenon remain underexplored. We conducted 15 in-depth interviews with informal caregivers to gain insight into their experiences and reactions to NA. Thematic analysis identified seven sub-themes related to carers' experience and eight sub-themes concerning their reactions. These themes emerged across three levels, namely, PwD, informal caregiver and the environment. Most phenomena occurred at a dyadic level between PwD and informal caregiver, highlighting the potential of interventions targeting dyadic coping. Informal caregivers feel insufficiently supported when sleep disturbances co-occur with NA. They primarily rely on self-initiated strategies and learn by experience. Caregivers mention the need for more advanced knowledge and skills in reacting to co-occurrence of sleep disturbances with NA or systemic support in terms of dealing with emergencies. Caregivers also reflect extensively on the impact of challenging behaviors during the night on their mental and physical well-being. Notably, no non-pharmacological interventions for NA adequately address the themes identified in this study, highlighting the urgent need for integrative approaches and recognition of caregiver wellbeing as a core outcome, not a secondary consideration in interventions.