Ability of the Fitbit Alta HR to quantify and classify sleep in patients with suspected central disorders of hypersomnolence: A comparison against polysomnography.

Measuring sleep duration and early onset rapid eye movement sleep (REMS) is critical in the assessment of suspected central disorders of hypersomnolence (CDH). Current multi-sensor activity trackers that integrate accelerometry and heart rate are purported to accurately quantify sleep time and REMS; however, their utility in suspected CDH has not been established. This investigation aimed to determine the ability of a current, multi-sensor tracker, Fitbit Alta HR (FBA-HR), to quantify and classify sleep in patients with suspected CDH relative to polysomnography (PSG). Forty-nine patients (46 female; mean age, 30.3 ± 9.84 years) underwent ad libitum PSG with concurrent use of the FBA-HR. FBA-HR sleep variable quantification was assessed using Bland-Altman analysis. FBA-HR all sleep (AS), light sleep (LS; PSG N1 + N2), deep sleep (DS; PSG N3) and REMS classification was evaluated using epoch-by-epoch comparisons. FBA-HR-detected sleep-onset rapid eye movement periods (SOREMPs) were compared against PSG SOMREMPs. FBA-HR displayed significant overestimation of total sleep time (11.6 min), sleep efficiency (1.98%) and duration of deep sleep (18.2 min). FBA-HR sensitivity and specificity were as follows: AS, 0.96, 0.58; LS, 0.73, 0.72;DS, 0.67, 0.92; REMS, 0.74, 0.93. The device failed to detect any nocturnal SOREMPs. Device performance did not differ appreciably among diagnostic subgroups. These results suggest FBA-HR cannot replace EEG-based measurements of sleep and wake in the diagnostic assessment of suspected CDH, and that improvements in device performance are required prior to adoption in clinical or research settings.

Effects of losartan and allopurinol on cardiorespiratory regulation in obstructive sleep apnoea.

NEW FINDINGS: What is the central question of this study? In sleep apnoea, a putative link between intermittent hypoxia and hypertension is the generation of oxygen radicals by angiotensin II and xanthine oxidase within the chemoreflex arc and vasculature. We tested whether chemoreflex control of sympathetic outflow, hypoxic vasodilatation and blood pressure are altered by angiotensin blockade (losartan) and/or xanthine oxidase inhibition (allopurinol). What is the main finding and its importance? Both drugs lowered blood pressure without altering sympathetic outflow, reducing chemoreflex sensitivity or enhancing hypoxic vasodilatation. Losartan and allopurinol are effective therapies for achieving blood pressure control in sleep apnoea. ABSTRACT: Chemoreflex sensitization produced by chronic intermittent hypoxia in rats is attenuated by angiotensin II type 1 receptor (AT1 R) blockade. Both AT1 R blockade and xanthine oxidase inhibition ameliorate chronic intermittent hypoxia-induced endothelial dysfunction. We hypothesized that treatment with losartan and allopurinol would reduce chemoreflex sensitivity and improve hypoxic vasodilatation in patients with obstructive sleep apnoea. Eighty-six hypertensive patients with apnoea-hypopnoea index ≥25 events h-1 and no other cardiovascular, pulmonary, renal or metabolic disease were randomly assigned to receive allopurinol, losartan or placebo for 6 weeks. Treatment with other medications and/or continuous positive airway pressure remained unchanged. Tests of chemoreflex sensitivity and hypoxic vasodilatation were performed during wakefulness before and after treatment. Ventilation (pneumotachography), muscle sympathetic nerve activity (microneurography), heart rate (electrocardiography), arterial oxygen saturation (pulse oximetry), blood pressure (sphygmomanometry), forearm blood flow (venous occlusion plethysmography) and cerebral flow velocity (transcranial Doppler ultrasound) were measured during eupnoeic breathing and graded reductions in inspired O2 tension. Losartan and allopurinol lowered arterial pressure measured during eupnoeic breathing and exposure to acute hypoxia. Neither drug altered the slopes of ventilatory, sympathetic or cardiovascular responses to acute hypoxia. We conclude that losartan and allopurinol are viable pharmacotherapeutic adjuncts for achieving blood pressure control in hypertensive obstructive sleep apnoea patients, even those who are adequately treated with continuous positive airway pressure.

Objective measures of sleep duration and continuity in major depressive disorder with comorbid hypersomnolence: a primary investigation with contiguous systematic review and meta-analysis.

Hypersomnolence plays an important role in the presentation, treatment and course of mood disorders. However, there has been relatively little research that examines objective measures of sleep duration and continuity in patients with depression and hypersomnolence, despite the use of these factors in sleep medicine nosological systems. This study compared total sleep time and efficiency measured by naturalistic actigraphic recordings followed by ad libitum polysomnography (PSG; without prescribed wake time) in 22 patients with major depressive disorder and co-occurring hypersomnolence against age- and sex-matched healthy sleeper controls. The major depressive disorder and co-occurring hypersomnolence group demonstrated significantly longer sleep duration compared with healthy sleeper controls quantified by sleep diaries, actigraphy and ad libitum PSG. No between-group differences in sleep efficiency (SE), latency to sleep or wake after sleep onset were observed when assessed using objective measures. To further contextualize these findings within the broader scientific literature, a systematic review was performed to identify other comparable investigations. A meta-analysis of pooled data demonstrated patients with mood disorders and co-occurring hypersomnolence have significantly greater sleep duration and similar SE compared with healthy controls when assessed using ad libitum PSG. These results suggest current sleep medicine nosology that distinguishes hypersomnia associated with psychiatric disorders primarily as a construct characterized by low SE and increased time in bed may not be accurate. Future studies that establish the biological bases hypersomnolence in mood disorders, as well as clarify the accuracy of nosological thresholds to define excessive sleep duration, are needed to refine the diagnosis and treatment of these disorders.

An Update on the Use of Sedative-Hypnotic Medications in Psychiatric Disorders.

Sleep disturbance is a common clinical problem experienced by patients with a wide range of psychiatric disorders. Accumulating evidence has demonstrated that insomnia is a comorbid process that affects the course and treatment of a number of forms of mental illness. The efficacy and safety of sedative-hypnotic medications have largely been established in patients who do not have comorbid psychiatric disorders, underscoring the need for further research in this sphere. This review summarizes pertinent findings in the recent literature that have examined the role of hypnotic medication in the treatment of psychiatric illness, and highlights potential areas that may prove fruitful avenues of future research.

The 5α-reductase inhibitor finasteride is not associated with alterations in sleep spindles in men referred for polysomnography.

OBJECTIVE: Endogenous neurosteroids that potentiate the gamma-aminobutyric acid type A (GABAA ) receptor are thought to enhance the generation of sleep spindles. This study tested the hypothesis that the 5α-reductase inhibitor finasteride, an agent associated with reductions in neurosteroids, would be associated with reduced sleep spindles in men referred for polysomnography. METHODS: Spectral analysis and spindle waveform detection were performed on electroencephalographic (EEG) sleep data in the 11-16 Hz sigma band, as well as several subranges, from 27 men taking finasteride and 27 matched comparison patients (ages 18 to 81 years). RESULTS: No significant differences between groups were observed for spectral power or sleep spindle morphology measures, including spindle density, amplitude, duration, and integrated spindle activity. CONCLUSIONS: Contrary to our hypothesis, these findings demonstrate that finasteride is not associated with alterations in sleep spindle range activity or spindle morphology parameters.

Sleep coaches: characterization of a burgeoning pediatric provider group from Internet advertisements for services.

Sleep coaches are an emerging group of pediatric providers whose scope of services and regional distribution have not been well characterized. This descriptive analysis used Internet data to identify sleep coaches and certification programs in the US; we found a sizeable diversity of backgrounds, training, services offered, and pricing.

Seasonal trends in sleep-disordered breathing: evidence from Internet search engine query data.

OBJECTIVE: The primary aim of the current study was to test the hypothesis that there is a seasonal component to snoring and obstructive sleep apnea (OSA) through the use of Google search engine query data. METHODS: Internet search engine query data were retrieved from Google Trends from January 2006 to December 2012. Monthly normalized search volume was obtained over that 7-year period in the USA and Australia for the following search terms: "snoring" and "sleep apnea". Seasonal effects were investigated by fitting cosinor regression models. In addition, the search terms "snoring children" and "sleep apnea children" were evaluated to examine seasonal effects in pediatric populations. RESULTS: Statistically significant seasonal effects were found using cosinor analysis in both USA and Australia for "snoring" (p < 0.00001 for both countries). Similarly, seasonal patterns were observed for "sleep apnea" in the USA (p = 0.001); however, cosinor analysis was not significant for this search term in Australia (p = 0.13). Seasonal patterns for "snoring children" and "sleep apnea children" were observed in the USA (p = 0.002 and p < 0.00001, respectively), with insufficient search volume to examine these search terms in Australia. All searches peaked in the winter or early spring in both countries, with the magnitude of seasonal effect ranging from 5 to 50 %. CONCLUSIONS: Our findings indicate that there are significant seasonal trends for both snoring and sleep apnea internet search engine queries, with a peak in the winter and early spring. Further research is indicated to determine the mechanisms underlying these findings, whether they have clinical impact, and if they are associated with other comorbid medical conditions that have similar patterns of seasonal exacerbation.

Seasonal trends in tinnitus symptomatology: evidence from Internet search engine query data.

The primary aim of this study was to test the hypothesis that the symptom of tinnitus demonstrates a seasonal pattern with worsening in the winter relative to the summer using Internet search engine query data. Normalized search volume for the term 'tinnitus' from January 2004 through December 2013 was retrieved from Google Trends. Seasonal effects were evaluated using cosinor regression models. Primary countries of interest were the United States and Australia. Secondary exploratory analyses were also performed using data from Germany, the United Kingdom, Canada, Sweden, and Switzerland. Significant seasonal effects for 'tinnitus' search queries were found in the United States and Australia (p < 0.00001 for both countries), with peaks in the winter and troughs in the summer. Secondary analyses demonstrated similarly significant seasonal effects for Germany (p < 0.00001), Canada (p < 0.00001), and Sweden (p = 0.0008), again with increased search volume in the winter relative to the summer. Our findings indicate that there are significant seasonal trends for Internet search queries for tinnitus, with a zenith in winter months. Further research is indicated to determine the biological mechanisms underlying these findings, as they may provide insights into the pathophysiology of this common and debilitating medical symptom.

Prevalence and Course of Idiopathic Hypersomnia in the Wisconsin Sleep Cohort Study.

BACKGROUND AND OBJECTIVES: Idiopathic hypersomnia (IH) is a CNS disorder of hypersomnolence of unknown etiology. Due to the requirement for objective sleep testing to diagnose the disorder, there are currently no population-based estimates of the prevalence of IH nor data regarding the longitudinal course of IH in naturalistic settings. METHODS: Subjective and objective data from the Wisconsin Sleep Cohort study were used to identify cases with probable IH from participants with polysomnography and multiple sleep latency test data. Demographic, polysomnographic, and symptom-level data were compared between those with and without IH. Longitudinal trajectories of daytime sleepiness among those with IH were assessed to evaluate symptom persistence or remission over time. RESULTS: From 792 cohort study participants with available polysomnography and multiple sleep latency test data, 12 cases with probable IH were identified resulting in an estimated prevalence of IH of 1.5% (95% CI 0.7-2.5, p < 0.0001). Consistent with inclusion/exclusion criteria, cases with IH had more severe sleepiness and sleep propensity, despite similar or longer sleep times. Longitudinal data (spanning 12.1 ± 4.3 years) demonstrated a chronic course of sleepiness for most of the cases with IH, though pathologic somnolence remitted in roughly 40% of cases. DISCUSSION: These results demonstrate IH is more common in the working population than generally assumed with a prevalence on par with other common neurologic and psychiatric conditions. Further efforts to identify and diagnose those impaired by unexplained daytime somnolence may help clarify the causes of IH and the mechanisms underlying symptomatic remission.

Associations of sleep duration and daytime sleepiness with plasma amyloid beta and cognitive performance in cognitively unimpaired, middle-aged and older African Americans.

STUDY OBJECTIVES: Given the established racial disparities in both sleep health and dementia risk for African American populations, we assess cross-sectional and longitudinal associations of self-report sleep duration (SRSD) and daytime sleepiness with plasma amyloid beta (Aß) and cognition in an African American (AA) cohort. METHODS: In a cognitively unimpaired sample drawn from the African Americans Fighting Alzheimer's in Midlife (AA-FAiM) study, data on SRSD, Epworth Sleepiness Scale, demographics, and cognitive performance were analyzed. Aß40, Aß42, and the Aß42/40 ratio were quantified from plasma samples. Cross-sectional analyses explored associations between baseline predictors and outcome measures. Linear mixed-effect regression models estimated associations of SRSD and daytime sleepiness with plasma Aß and cognitive performance levels and change over time. RESULTS: One hundred and forty-seven participants comprised the cross-sectional sample. Baseline age was 63.2 ±â€…8.51 years. 69.6% self-identified as female. SRSD was 6.4 ±â€…1.1 hours and 22.4% reported excessive daytime sleepiness. The longitudinal dataset included 57 participants. In fully adjusted models, neither SRSD nor daytime sleepiness is associated with cross-sectional or longitudinal Aß. Associations with level and trajectory of cognitive test performance varied by measure of sleep health. CONCLUSIONS: SRSD was below National Sleep Foundation recommendations and daytime sleepiness was prevalent in this cohort. In the absence of observed associations with plasma Aß, poorer self-reported sleep health broadly predicted poorer cognitive function but not accelerated decline. Future research is necessary to understand and address modifiable sleep mechanisms as they relate to cognitive aging in AA at disproportionate risk for dementia. CLINICAL TRIAL INFORMATION: Not applicable.

Effects of sleep deprivation on brain bioenergetics, sleep, and cognitive performance in cocaine-dependent individuals.

In cocaine-dependent individuals, sleep is disturbed during cocaine use and abstinence, highlighting the importance of examining the behavioral and homeostatic response to acute sleep loss in these individuals. The current study was designed to identify a differential effect of sleep deprivation on brain bioenergetics, cognitive performance, and sleep between cocaine-dependent and healthy control participants. 14 healthy control and 8 cocaine-dependent participants experienced consecutive nights of baseline, total sleep deprivation, and recovery sleep in the research laboratory. Participants underwent ³¹P magnetic resonance spectroscopy (MRS) brain imaging, polysomnography, Continuous Performance Task, and Digit Symbol Substitution Task. Following recovery sleep, ³¹P MRS scans revealed that cocaine-dependent participants exhibited elevated global brain ß-NTP (direct measure of adenosine triphosphate), α-NTP, and total NTP levels compared to those of healthy controls. Cocaine-dependent participants performed worse on the Continuous Performance Task and Digit Symbol Substitution Task at baseline compared to healthy control participants, but sleep deprivation did not worsen cognitive performance in either group. Enhancements of brain ATP levels in cocaine dependent participants following recovery sleep may reflect a greater impact of sleep deprivation on sleep homeostasis, which may highlight the importance of monitoring sleep during abstinence and the potential influence of sleep loss in drug relapse.

Don't hold PAT: watch for and correct oximetry artifact.

This study evaluated the accuracy of the algorithmic oxygen saturation (SpO2) nadir detection of WatchPAT (Zoll/Itamar, Caesarea, Israel) compared with visual inspection in a real-world setting. SpO2 tracings for 209 consecutive adult WatchPAT recordings were reviewed for SpO2 artifact, with erroneous SpO2 data removed manually. Error rates for SpO2 minima were determined across all studies, and relationships between correct and erroneous studies examined. The overall error rate for SpO2 nadir was 22.5%. Erroneous studies had overall less time spent at SpO2 ≤ 88%, higher true SpO2 nadir, lower mean body mass index, and greater artifact time; however, these variables were not associated with the magnitude of discrepancy between manual and algorithmically derived SpO2 minima. These data demonstrate that SpO2 nadir determined by WatchPAT algorithms should not be considered universally accurate. Like other home sleep apnea tests, visual inspection and manual correction of the study data are often required to derive accurate clinical results. CITATION: Plante DT, Rumble ME. Don't hold PAT: watch for and correct oximetry artifact. J Clin Sleep Med. 2023;19(12):2113-2116.

Cardiorespiratory Fitness Attenuates the Deleterious Effects of Sleep Apnea on Cerebral Structure and Perfusion in the Wisconsin Sleep Cohort Study.

BACKGROUND: Emerging evidence suggests that age-related changes in cerebral health may be sensitive to vascular risk modifiers, such as physical activity and sleep. OBJECTIVE: We examine whether cardiorespiratory fitness modifies the association of obstructive sleep apnea (OSA) severity with MRI-assessed measures of cerebral structure and perfusion. METHODS: Using data from a cross-sectional sample of participants (n = 129, 51% female, age range 49.6-85.3 years) in the Wisconsin Sleep Cohort study, we estimated linear models of MRI-assessed total and regional gray matter (GM) and white matter (WM) volumes, WM hyperintensity (WMH:ICV ratio), total lesion volume, and arterial spin labeling (ASL) cerebral blood flow (CBF), using an estimated measure of cardiorespiratory fitness (CRF) and OSA severity as predictors. Participants' sleep was assessed using overnight in-laboratory polysomnography, and OSA severity was measured using the apnea-hypopnea index (AHI), or the mean number of recorded apnea and hypopnea events per hour of sleep. The mean±SD time difference between PSG data collection and MRI data collection was 1.7±1.5 years (range: [0, 4.9 years]). RESULTS: OSA severity was associated with reduced total GM volume (ß=-0.064; SE = 0.023; p = 0.007), greater total WM lesion volume (interaction p = 0.023), and greater WMHs (interaction p = 0.017) in less-fit subjects. Perfusion models revealed significant differences in the association of AHI and regional CBF between fitness groups (interaction ps < 0.05). CONCLUSION: This work provides new evidence for the protective role of cardiorespiratory fitness against the deleterious effects of OSA on brain aging in late-middle age to older adults.

Associations between self-reported sleep patterns and health, cognition and amyloid measures: results from the Wisconsin Registry for Alzheimer's Prevention.

Previous studies suggest associations between self-reported sleep problems and poorer health, cognition, Alzheimer's disease pathology and dementia-related outcomes. It is important to develop a deeper understanding of the relationship between these complications and sleep disturbance, a modifiable risk factor, in late midlife, a time when Alzheimer's disease pathology may be accruing. The objectives of this study included application of unsupervised machine learning procedures to identify distinct subgroups of persons with problematic sleep and the association of these subgroups with concurrent measures of mental and physical health, cognition and PET-identified amyloid. Dementia-free participants from the Wisconsin Registry for Alzheimer's Prevention (n = 619) completed sleep questionnaires including the Insomnia Severity Index, Epworth Sleepiness Scale and Medical Outcomes Study Sleep Scale. K-means clustering analysis identified discrete sleep problem groups who were then compared across concurrent health outcomes (e.g. depression, self-rated health and insulin resistance), cognitive composite indices including episodic memory and executive function and, in a subset, Pittsburgh Compound B PET imaging to assess amyloid burden. Significant omnibus tests (P < 0.05) were followed with pairwise comparisons. Mean (SD) sample baseline sleep assessment age was 62.6 (6.7). Cluster analysis identified three groups: healthy sleepers [n = 262 (42.3%)], intermediate sleepers [n = 229 (37.0%)] and poor sleepers [n = 128 (20.7%)]. All omnibus tests comparing demographics and health measures across sleep groups were significant except for age, sex and apolipoprotein E e4 carriers; the poor sleepers group was worse than one or both of the other groups on all other measures, including measures of depression, self-reported health and memory complaints. The poor sleepers group had higher average body mass index, waist-hip ratio and homeostatic model assessment of insulin resistance. After adjusting for covariates, the poor sleepers group also performed worse on all concurrent cognitive composites except working memory. There were no differences between sleep groups on PET-based measures of amyloid. Sensitivity analyses indicated that while different clustering approaches resulted in different group assignments for some (predominantly the intermediate group), between-group patterns in outcomes were consistent. In conclusion, distinct sleep characteristics groups were identified with a sizable minority (20.7%) exhibiting poor sleep characteristics, and this group also exhibited the poorest concurrent mental and physical health and cognition, indicating substantial multi-morbidity; sleep group was not associated with amyloid PET estimates. Precision-based management of sleep and related factors may provide an opportunity for early intervention that could serve to delay or prevent clinical impairment.

Altered slow wave activity in major depressive disorder with hypersomnia: a high density EEG pilot study.

Hypersomnolence in major depressive disorder (MDD) plays an important role in the natural history of the disorder, but the basis of hypersomnia in MDD is poorly understood. Slow wave activity (SWA) has been associated with sleep homeostasis, as well as sleep restoration and maintenance, and may be altered in MDD. Therefore, we conducted a post-hoc study that utilized high density electroencephalography (hdEEG) to test the hypothesis that MDD subjects with hypersomnia (HYS+) would have decreased SWA relative to age- and sex-matched MDD subjects without hypersomnia (HYS-) and healthy controls (n=7 for each group). After correction for multiple comparisons using statistical non-parametric mapping, HYS+ subjects demonstrated significantly reduced parieto-occipital all-night SWA relative to HYS- subjects. Our results suggest hypersomnolence may be associated with topographic reductions in SWA in MDD. Further research using an adequately powered prospective design is indicated to confirm these findings.

Sex-related differences in sleep slow wave activity in major depressive disorder: a high-density EEG investigation.

BACKGROUND: Sleep disturbance plays an important role in major depressive disorder (MDD). Prior investigations have demonstrated that slow wave activity (SWA) during sleep is altered in MDD; however, results have not been consistent across studies, which may be due in part to sex-related differences in SWA and/or limited spatial resolution of spectral analyses. This study sought to characterize SWA in MDD utilizing high-density electroencephalography (hdEEG) to examine the topography of SWA across the cortex in MDD, as well as sex-related variation in SWA topography in the disorder. METHODS: All-night recordings with 256 channel hdEEG were collected in 30 unipolar MDD subjects (19 women) and 30 age and sex-matched control subjects. Spectral analyses of SWA were performed to determine group differences. SWA was compared between MDD and controls, including analyses stratified by sex, using statistical non-parametric mapping to correct for multiple comparisons of topographic data. RESULTS: As a group, MDD subjects demonstrated significant increases in all-night SWA primarily in bilateral prefrontal channels. When stratified by sex, MDD women demonstrated global increases in SWA relative to age-matched controls that were most consistent in bilateral prefrontal regions; however, MDD men showed no significant differences relative to age-matched controls. Further analyses demonstrated increased SWA in MDD women was most prominent in the first portion of the night. CONCLUSIONS: Women, but not men with MDD demonstrate significant increases in SWA in multiple cortical areas relative to control subjects. Further research is warranted to investigate the role of SWA in MDD, and to clarify how increased SWA in women with MDD is related to the pathophysiology of the disorder.

Mastery learning program to teach sleep study scoring.

STUDY OBJECTIVES: Scoring a polysomnogram is an essential skill for sleep medicine trainees to meet Accreditation Council for Graduate Medical Education Sleep Medicine Milestones. Appraisal is based on faculty evaluation rather than objective competency assessment. We developed a computer-based polysomnogram scoring curriculum, utilizing the mastery learning method, then compared achievement of competency using the new curriculum against standard institutional training. METHODS: The scoring program consisted of a pretest assessment, sequential acquisition of knowledge utilizing online modules, a posttest, and competency assessment. Fellows needed to demonstrate mastery of each module before moving ahead. Competency was demonstrating ≥ 90% on interscorer reliability assessment on 5 studies (out of up to 10 attempts). Participating fellows were assigned to Mastery Learning Participants (MLP) or Traditional Learning Participants (TLP) groups and completed the program within the first 1-3 months of training. RESULTS: Of 87 fellows enrolled in the program, 75 participants completed the program (40 MLP and 35 TLP). Among completers, there was no difference in the proportion that achieved competency (MLP 90.0% vs TLP 97.1%; P = .36) or studies needed to achieve competency (MLP 7.25 ± 1.3 vs TLP 7.41 ± 1.3; P = .60). Pretest scores were not significantly different between groups (MLP 61.2% ± 15.9 vs TLP 57.6% ± 16.6; P = .35), but MLP posttest scores were higher than TLP (MLP 80.9% ± 8.8 vs TLP 76.4% ± 9.8; P = .04). CONCLUSIONS: We demonstrated similar outcomes utilizing a novel, computer-based modular interactive course compared to traditional methods of teaching polysomnogram scoring. We used a mastery learning paradigm and set specific objective competency levels for this skill. CITATION: Epstein LJ, Plante DT, Rosen IM. Mastery learning program to teach sleep study scoring. J Clin Sleep Med. 2022;18(12):2745-2750.

Physical Activity and Physical and Mental Health in Middle-Aged Adults with Down Syndrome.

Background: Adults with Down syndrome have an increased risk of aging-related physical and mental health conditions and experience them at an earlier age than the general population. There is a need to investigate modifiable lifestyle factors that may reduce risk for these conditions. Method: The present study investigated the associations between physical activity (i.e., sedentary behavior and moderate-to-vigorous activity) assessed via accelerometer across 7 days and caregiver-reported physical and mental health of 66 non-demented middle-aged adults with Down Syndrome aged 25-55 years (52% female). Results: Regression analyses indicated that more time spent in moderate intensity physical activity was associated with less risk of sleep apnea (b = -.031 p = .004) and endocrine/metabolic conditions (b = -.046 p = .009), and lower total number of physical health conditions (b = -.110 p =.016) and anxiety disorders (b = -.021 p =.049) after controlling for relevant sociodemographics. After also adjusting for BMI, the association between time spent in moderate intensity physical activity and sleep apnea (b=-.035, p = .002), endocrine/metabolic conditions (b=-.033, p = .045) and total physical health (b=-.091, p =.026) remained significant Unexpectedly, time spent in sedentary behavior was negatively associated with musculoskeletal conditions (b=-.017, p = .044). Conclusion: Findings indicate important associations between physical activity in everyday life and the physical and mental health of adults with Down syndrome. Social policies and interventions aimed at reducing time spent sitting around (i.e., sedentary behavior) and encouraging moderate-to-vigorous activity may be a low-burden and low-cost mechanism for fostering healthy physical and mental aging in the Down syndrome population.

The Evolving Nexus of Sleep and Depression.

Sleep disturbances and depression are closely linked and share a bidirectional relationship. These interconnections can inform the pathophysiology underlying each condition. Insomnia is an established and modifiable risk factor for depression, the treatment of which offers the critical opportunity to prevent major depressive episodes, a paradigm-shifting model for psychiatry. Identification of occult sleep disorders may also improve outcomes in treatment-resistant depression. Sleep alterations and manipulations may additionally clarify the mechanisms that underlie rapid-acting antidepressant therapies. Both sleep disturbance and depression are heterogeneous processes, and evolving standards in psychiatric research that consider the transdiagnostic components of each are more likely to lead to translational progress at their nexus. Emerging tools to objectively quantify sleep and its disturbances in the home environment offer great potential to advance clinical care and research, but nascent technologies require further advances and validation prior to widespread application at the interface of sleep and depression.