Sleep Complaints Research Articles

Impacts of aging on circadian rhythm and related sleep disorders

Circadian rhythm is an essential component of biology that organizes the internal synchrony of the organism in response to the environment. Aging significantly impacts circadian rhythm and is also associated with specific sleep complaints in mammals, including earlier awakening and decreased sleep consolidation at the end of the night. However, the regulation mechanism of aging on the circadian rhythm is far from clear. To further understand the impact of aging, we use an existing mathematical model of circadian rhythm combined with the aging system to explore the effects of aging on circadian rhythm and two kinds of sleep disorders, familial late sleep syndrome (FASPS) and delayed sleep syndrome (DSPS). We get a few intriguing findings from numerical simulations. Aging weakens rhythmicity by reducing the amplitude of circadian rhythm. Aging exacerbates the sleep pattern of being early to bed and early to rise by shortening the period of circadian rhythm and advancing the entrainment phase. Aging reduces the ability of the circadian rhythm to respond to light. The elderly need stronger light to get entrainment with the environmental light cycle. It is more difficult for the elderly to recover from disturbed light. Especially elderly people take a longer time to overcome jet lag. Aging worsens the “morningness” of FASPS disorder patients and improves the symptoms of DSPS disorder patients. This study helps to better understand the impacts of aging on circadian rhythm and sleep disorders and provides theoretical support for the treatment of circadian disorders in the elderly.

Sleep disruption due to nocturnal heartburn: a review of the evidence and clinical implications

Nocturnal heartburn (NHB) is a symptom that affects up to 25% of the general population and has been shown to cause sleep disruption that adversely affects quality of life and psychomotor performance. Few studies have evaluated the association between occasional NHB and sleep disturbances; therefore, this connection may be underappreciated and left untreated by the primary care provider and patient, with potentially significant negative clinical consequences and effects on quality of life. This review sought to describe what is currently known about the interplay between occasional NHB and sleep disruption, and identify whether acid suppression therapy can improve symptoms of occasional NHB and associated sleep disruptions. The pathophysiology of heartburn-induced sleep disruption appears to follow a bidirectional cycle due to the normal physiologic changes that occur in the upper gastrointestinal tract during sleep and due to the potential for heartburn symptoms to cause sleep arousal. The majority of the identified studies suggested that pharmacologic interventions for acid reduction, including proton pump inhibitors or histamine type-2 receptor antagonists (H2RAs), improved objective and/or subjective sleep outcomes among individuals with gastroesophageal reflux disease (GERD) and NHB. Several studies specific to famotidine demonstrated that treatment with 10 mg or 20 mg reduced nighttime awakenings due to NHB. In conclusion, NHB symptoms can cause sleep dysfunction that can have a profound adverse downstream effect on quality of life, next-day functioning, and health-related outcomes. The current approach to managing occasional NHB is similar to that associated with GERD, highlighting the need for studies specific to the occasional heartburn population. Health care providers should investigate NHB as one of the potential causes of sleep complaints, and patients with heartburn should be questioned about sleep quality, recalled arousals, next-day vitality, early fatigue, and next-day functioning.

SEX DIFFERENCES IN THE ROLE OF SLEEP ON EXECUTIVE FUNCTION IN OLDER ADULTS

Abstract Advancing age is associated with a decline in sleep quality and cognitive performance. Previous work has shown that women report a higher number of sleep complaints, possibly due to hormonal and physiologic developmental changes across the lifespan. However, whether the effects of sleep quality on cognitive performance differ between sexes in older populations remains unclear. To address this gap, we analyzed data from 117 cognitively normal participants (44 men and 73 women) aged 60 and older (M = 74.82, SD = 6.52) to compare the effects of objectively measured sleep on executive function. Total sleep time was recorded with the GT9X Link Actigraph worn for seven consecutive days. The composite score of executive function was derived from a confirmatory factor analysis consisting of four separate tests (Verbal Fluency, Trail Making Test Part B, Digit Symbol Substitution Test, and Stroop Interference). We used hierarchical multiple regression to investigate sex differences in the effects of total sleep time on executive function. A quadratic model of total sleep time was a significant predictor of executive function in women (β = -.251, p = .034), but not in men adjusting for age and education. Longer sleep duration predicted improved executive function, but the performance decreased with oversleeping. These findings imply that interventions aimed at optimizing sleep duration may be beneficial for executive function in older women. Further research is necessary to identify sex-specific sleep requirements, which can inform the development of personalized interventions for older adults.

Factors associated with reduced sleep among spouses and caregivers of older adults with varying levels of cognitive decline.

Caregivers of persons with cognitive decline (PWCD) are at increased risk of poor sleep quantity and quality. It is unclear whether this is due to factors in the caregiver versus in the PWCD. This secondary data analysis using Aging, Demographics, and Memory Study data from the Health Retirement Study examined factors contributing to reduced sleep/rest among spouses and caregivers of older adults with varying levels of cognitive decline (cognitively normal (CN), cognitive impairment but not dementia (CIND), or dementia). In our preliminary analysis, among N = 218 spouses (not necessarily caregivers) (mean age (SD) = 73.77 (7.30); 70.64% female) of older adults with varying levels of cognitive decline, regression revealed that frequency of sleep complaints was lowest among spouses with CN partners, second highest with CIND partners, and highest with dementia-partners, X2 = 26.810, P = 0.002. among n = 136 caregivers of PWCD (mean age (SD) = 59.27 (13.97); 74.26% female; 22.79% spouses), we analyzed whether caregiver reduced sleep/rest was predicted by PWCD factors (i.e., frequent nighttime waking, dementia severity) and/or caregiver factors (i.e., depression symptoms, caregiver role overload). Regression revealed that caregiver depression symptoms (d = 0.62) and role overload (d = 0.88), but not PWCD factors, were associated with reduced caregiver sleep/rest after adjusting for demographic factors, caregiving frequency, and shared-dwelling status (overall model: X2 = 31.876, P = 0.002). Exploratory analyses revealed that a caregiver was 7.901 times more likely (95% CI: 0.99-63.15) to endorse experiencing reduced sleep/rest if back-up care was not available (P = 0.023). Findings highlight that the frequency of reported sleep problems among spouses increases in a stepwise fashion when partners have dementia versus CIND versus CN. The results also emphasise that caregiver mental health and burden are strongly associated with caregiver sleep disturbances and thus may be targets of intervention for caregiver sleep problems.

The Menstrual Cycle and Sleep.

Aspects of sleep change across the menstrual cycle in some women. Poorer sleep quality in the premenstrual phase and menstruation is common in women with premenstrual symptoms or painful menstrual cramps. Although objective sleep continuity remains unchanged across the regular, asymptomatic menstrual cycle, activity in the sleep electroencephalogram varies, with a prominent increase in sleep spindle activity in the postovulatory luteal phase, when progesterone is present, relative to the follicular phase. Menstrual cycle phase, reproductive stage, and menstrual-related disorders should be considered when assessing women's sleep complaints.

The impact of the COVID-19 pandemic on sleep disorders among Nursing professionals.

to analyze the factors related to sleep disorders reported by Nursing professionals during the COVID-19 pandemic. this is a cross-sectional and analytical study conducted with Nursing professionals from all Brazilian regions. Sociodemographic data, working conditions and questions about sleep disorders were collected. The Poisson regression model with repeated measures was used to estimate the Relative Risk. 572 answers were analyzed, which revealed that non-ideal sleep duration, poor sleep quality and dreams about the work environment were predominant during the pandemic, with 75.2%, 67.1% and 66.8% respectively; as well as complaints of difficulty sleeping, daytime sleepiness and non-restorative sleep during the pandemic were reported by 523 (91.4%), 440 (76.9%) and 419 (73.2%) of the Nursing professionals, respectively. The relative risk of having such sleep disorders during the pandemic was significant for all variables and categories studied. non-ideal sleep duration, poor sleep quality, dreams about the work environment, complaints regarding difficulty sleeping, daytime sleepiness and non-restorative sleep were the predominant sleep disorders among Nursing professionals during the pandemic. Such findings point to possible consequences on health, as well as on the quality of the work performed.

Bedtime regularity predicts positive affect among veterans with posttraumatic stress disorder: an ecological momentary assessment study

BackgroundRegularizing bedtime and out-of-bed times is a core component of behavioral treatments for sleep disturbances common among patients with posttraumatic stress disorder (PTSD). Although improvements in subjective sleep complaints often accompany improvements in PTSD symptoms, the underlying mechanism for this relationship remains unclear. Given that night-to-night sleep variability is a predictor of physical and mental well-being, the present study sought to evaluate the effects of bedtime and out-of-bed time variability on daytime affect and explore the optimal window lengths of over which variability is calculated.MethodsFor about 30 days, male U.S. military veterans with PTSD (N = 64) in a residential treatment program provided ecological momentary assessment data on their affect and slept on beds equipped with mattress actigraphy. We computed bedtime and out-of-bed time variability indices with varying windows of days. We then constructed multilevel models to account for the nested structure of our data and evaluate the impact of bedtime and out-of-bed time variability on daytime affect.ResultsMore regular bedtime across 6–9 days was associated with greater subsequent positive affect. No similar effects were observed between out-of-bed time variability and affect.ConclusionsMultiple facets of sleep have been shown to differently predict daily affect, and bedtime regularity might represent one of such indices associated with positive, but not negative, affect. A better understanding of such differential effects of facets of sleep on affect will help further elucidate the complex and intertwined relationship between sleep and psychopathology.Trial registrationThe trial retrospectively was registered on the Defense Technical Information Center website: Award # W81XWH-15–2-0005.

Reduced subjective sleep quality in people rating themselves as electro-hypersensitive: An observational study

BackgroundDisturbed sleep is among the most frequent health complaints of people exposed to radio frequency electromagnetic fields (RF-EMF) used in mobile telecommunication, particularly in individuals who consider themselves as EMF hypersensitive (EHS). We aimed at investigating whether the EHS status per se is associated with sleep complaints. Because allelic variants of the gene encoding the L-type, voltage-gated calcium channel Cav1.2 (CACNA1C) were previously associated with sleep complaints reminiscent of those reported by EHS individuals, we also explored whether self-rated EHS status and sleep quality associate with these gene variants. MethodsA total of 2′040 participants (1′381 females) aged 18–30 years completed online, validated questionnaires on EMF sensitivity, subjective sleep quality, daytime sleepiness, mentation during sleep, and diurnal preference. They also provided a saliva sample for genotyping three functional variants of CACNA1C (rs7304986, rs16929277 and rs2302729). Eligible participants endorsing the question “Are you electro-hypersensitive?” were considered as “EHS” (n = 105), those denying this question yet believing to develop detrimental health symptoms due to prevailing electromagnetic pollution as “attributers” (n = 254), and the remaining participants as “non-EHS” (n = 1′406). We combined the EHS and attributers into one group for binary analyses. In exploratory analyses, we then tested possible associations between EMF sensitivity, subjective sleep variables and CACNA1C variants using linear and logistic regression. We used age, sex, level of education, presence of sleep disorders and habitual mobile phone use as covariates and corrected with Benjamini-Hochberg False Discovery Rate for multiple comparisons. ResultsThe EHS/attributers consistently reported prolonged sleep latency, reduced sleep quality, higher sleepiness and more nocturnal mentation when compared to non-EHS. Habitual mobile phone use was not associated with self-rated sleep latency and sleep quality scores. While the T-allele of variant rs2302729 of CACNA1C was associated with both, self-reported EMF sensitivity and reduced subjective sleep quality, we found no evidence for the hypothesis that EHS mediates impaired sleep quality via this allelic variant. ConclusionsIrrespective of reported RF-EMF exposure, self-rated EHS/attributers rated subjective sleep quality worse than non-EHS individuals. Trial registrationSwiss National Clinical Trials Portal (SNCTP000002285) and ClinicalTrials.gov (NCT03074617).

Validation of the Insomnia Severity Index among University Students in Korea

Insomnia is the most common sleep complaint in clinical practice, affecting both the physical and mental health of patients as well as many aspects of their life quality. Young adults, especially university students, are prone to a high prevalence of poor sleep quality or insomnia. Accurate assessment of insomnia severity among university students has become an important issue. One promising screening tool to identify clinically significant insomnia in the campus setting is the Insomnia Severity Index (ISI), a seven-item self-report measure designed to assess the nature and severity of one’s insomnia. Although the ISI has been validated in primary care settings in Korea, no studies have examined its factor structure for university students. This study aimed to analyze the psychometric properties of the Korean version of the ISI.<strong> </strong>A convenience sample of 252 undergraduate students aged 18-64 attending a four-year university in South Korea was recruited for the study. The collected data underwent exploratory factor analysis (EFA) and confirmatory factor analysis (CFA), which tested alternative models to determine the factorial structure of the ISI. Internal consistency and convergent and discriminant validity were examined. CFA findings showed that a two-factor model best fit the data. The ISI was found to be significantly correlated with higher depressive symptoms and possess adequate internal consistency. Our study confirmed that the ISI had insufficient reliability and good convergent and discriminant validity.<strong> </strong>This study generally supports the validity and factor structure of the ISI. Its two-factor structure is a psychometrically robust measure for evaluating the prevalence of insomnia.

Psychometric Properties and Clinical Utility of CBCL and P-GBI Sleep Items in Children and Adolescents

ABSTRACT Objective Sleep is crucial to overall health, playing a complex role in a wide range of mental health concerns in children and adults. Nevertheless, clinicians may not routinely assess sleep problems due to lack of awareness or limitations such as cost or time. Scoring sleep-related items embedded on broader scales may help clinicians get more out of tools they are already using. The current study explores evidence of reliability, validity, and clinical utility of sleep-related items embedded on two caregiver-report tools: the Child Behavior Checklist (CBCL) and Parent General Behavior Inventory (P-GBI). Method Youth aged 5–18 years and their parents were recruited from both an academic medical center (N = 759) and an urban community health center (N = 618). Caregivers completed the CBCL and P-GBI as part of a more comprehensive outpatient evaluation. Exploratory factor analyses, multi-group confirmatory factor analyses, and graded response models evaluated dimensionality, reliability, and invariance across samples. Correlations and receiver operating characteristic curve analyses probed associations with diagnostic and demographic variables. Results Two subscales emerged for each itemset. Across both samples, P-GBI sleep subscales were more reliable and consistent than CBCL sleep subscales, showed greater coverage of sleepiness and insomnia constructs, were better at discriminating individuals within a wider range of sleep complaints, and showed significant correlation with mood disorder diagnoses. Conclusions The P-GBI sleep items provide a brief, reliable measure for assessing distinct dimensions of sleep complaints and detecting mood symptoms or diagnoses related to the youth’s sleep functioning, making them a useful addition to clinical practice.

Major depressive episode with insomnia and excessive daytime sleepiness: A more homogeneous and severe subtype of depression

Previous studies have noted the crucial role of excessive daytime sleepiness (EDS) in the course of depressive illness, and more recently, a few studies documented its strong associations with an increased risk of suicide. While insomnia is associated with heightened emotional reactivity, suicidal behaviors, and increased relapses and recurrence. Our main hypothesis is that major depressive episodes (MDE) with insomnia and EDS are associated with more severe manifestations of depression. However, to date, no study has directly compared MDE with insomnia without EDS (Ins), and MDE with insomnia with EDS (InsEDS) using both subjective biomarkers (administration of self-assessment questionnaires for psychiatric evaluation and sleep complaints) and objective biomarkers (of sleep and circadian rhythms (using actigraphy). The InsEDS group, compared to the Ins group, exhibited significantly increased suicidal ideation, larger seasonal impacts on mood, alterations in sleep duration, weight, appetite, energy levels, and social activities throughout the year. Furthermore, they had significant delayed onset of daily activity measured with actigraphy. These findings provided new insights into the link between suicide, sleep, alertness, and biological clock. They also hold significant implications for identifying individuals with more severe depressive manifestations and for developing tailored and personalized therapeutic strategies.

Associations between Combined Psychological and Lifestyle Factors with Pain Intensity and/or Disability in Patients with Chronic Low Back Pain: A Cross-Sectional Study.

Chronic low back pain (CLBP) is common in primary care, causing disability and economic burden globally. We aimed to compare socio-demographic, health, lifestyle, and psychological factors in people with and without CLBP and correlate them with clinical outcomes in people with CLBP. A total of 253 volunteers with and 116 without CLBP provided sociodemographic information, daily habits, medical history, subjective sleep complaints (Penn State Sleep Questionnaire), low back pain intensity, and disability (Quebec Back Pain Disability Scale), as well as the Zung Self-Rating Scale for self-assessment of depression and Self-Rating Anxiety Scale. CLBP diagnosis was linked with female gender and older age, as well as a higher level of sleep complaints such as sleepiness, OSA and insomnia symptoms, and a higher prevalence of moderate to severe depressive symptoms. The combination of moderate to severe depressive symptoms with obstructive sleep apnea or insomnia symptoms was the most important predictive factor for functional disability in CBLP patients (OR 13.686, 95% CI 4.581-40.885; p < 0.001). In conclusion, depressive symptoms and subjective sleep complaints appear to relate to greater CLBP intensity and/or CLBP-related disability in people with CLBP. A holistic approach is crucial for treating chronic CLBP patients, including psychological and sleep issue assessment and management, to improve their quality of life.

The Increasing Prevalence of REM Sleep Behavior Disorder with Parkinson's Disease Progression: A Polysomnography-Supported Study.

Rapid eye movement (REM) sleep behavior disorder (RBD) is proposed as an early diagnostic marker in Parkinson's disease (PD). We investigated the frequency of RBD during the progression of PD in the advanced stages and identified potential risk factors for developing RBD earlier or later. We performed a retrospective analysis and determined the frequency of RBD in all PD in-patients (Hoehn and Yahr stages ≥3) with motor fluctuations who had undergone video-polysomnography (vPSG) for a sleep complaint or daytime sleepiness. To correct for selection bias, we analyzed the prevalence of RBD in PD patients from the DeNoPa cohort. PD patients with RBD were compared with PD without RBD. To identify potential risk factors, we performed multiple regression modeling. A total of 504 PD patients had vPSG. 37 were excluded due to missing REM or artifacts during REM. RBD was present in 406/467 (86.9%) PD patients. PD + RBD patients were older than PDnonRBD (69 ± 7.7 vs. 64 ± 9.2 years, P < 0.01), were more likely to have postural instability [234 (59.1%) vs. 19 (33.9%), P < 0.01], and were treated more often with antidepressants (other than SSRIs) [141 (34.7%) vs. 7 (13%), P < 0.01]. Multiple regression modeling identified predictors of RBD with an AUC of 0.78. The prevalence of RBD in patients with advanced PD is high and increases with disease severity, motor deficits, postural instability, orthostatic symptoms, and age. This suggests RBD is a progression marker of PD in patients with sleep complaints.

Understanding the Relationships Between Sleep Quality and Depression and Anxiety in Neurotrauma: A Scoping Review.

Sleep problems, depression, and anxiety are highly prevalent after a spinal cord injury (SCI) and traumatic brain injury (TBI) and may worsen functional outcomes and quality of life. This scoping review examined the existing literature to understand the relationships between sleep quality, depression, and anxiety in persons with SCI and TBI, and to identify gaps in the literature. A systematic search of seven databases was conducted. The findings of 30 eligible studies reporting associations between sleep quality and depression and/or anxiety after SCI or TBI were synthesized. The included studies were mostly cross-sectional and employed a range of subjective and objective measures of sleep quality. Poor subjective sleep quality and insomnia tended to be significantly associated with increased levels of depression and/or anxiety, but no such associations were reported when sleep quality was measured objectively. Two longitudinal studies observed worsening depressive symptoms over time were related to insomnia and persistent sleep complaints. Two interventional studies found that treating sleep problems improved symptoms of depression and anxiety. The findings of this review suggest that sleep and psychopathology are related in persons with neurotraumatic injuries. This has important therapeutic implications, because individuals may benefit from therapy targeting both sleep and psychological issues. More longitudinal and interventional studies are warranted to further understand the direction and strength of the relationships and how they impact patient outcomes.

Collagen peptide supplementation before bedtime reduces sleep fragmentation and improves cognitive function in physically active males with sleep complaints

PurposeThe primary aim of this study was to examine whether a glycine-rich collagen peptides (CP) supplement could enhance sleep quality in physically active men with self-reported sleep complaints.MethodsIn a randomized, crossover design, 13 athletic males (age: 24 ± 4 years; training volume; 7 ± 3 h·wk1) with sleep complaints (Athens Insomnia Scale, 9 ± 2) consumed CP (15 g·day1) or a placebo control (CON) 1 h before bedtime for 7 nights. Sleep quality was measured with subjective sleep diaries and actigraphy for 7 nights; polysomnographic sleep and core temperature were recorded on night 7. Cognition, inflammation, and endocrine function were measured on night 7 and the following morning. Subjective sleepiness and fatigue were measured on all 7 nights. The intervention trials were separated by ≥ 7 days and preceded by a 7-night familiarisation trial.ResultsPolysomnography showed less awakenings with CP than CON (21.3 ± 9.7 vs. 29.3 ± 13.8 counts, respectively; P = 0.028). The 7-day average for subjective awakenings were less with CP vs. CON (1.3 ± 1.5 vs. 1.9 ± 0.6 counts, respectively; P = 0.023). The proportion of correct responses on the baseline Stroop cognitive test were higher with CP than CON (1.00 ± 0.00 vs. 0.97 ± 0.05 AU, respectively; P = 0.009) the morning after night 7. There were no trial differences in core temperature, endocrine function, inflammation, subjective sleepiness, fatigue and sleep quality, or other measures of cognitive function or sleep (P > 0.05).ConclusionCP supplementation did not influence sleep quantity, latency, or efficiency, but reduced awakenings and improved cognitive function in physically active males with sleep complaints.

The contribution of sleep deprivation to suicidal behavior

Objective: This study has the objective correlate sleep disturbances and mood disorders with suicide behavior, showing that the quality of sleep, when altered, interferes negatively in the individual's daily life, compromising social and labor aspects significantly, leading to a higher incidence of psychiatric disorders, which can incite suicidal behaviors. Methods: This article presents a narrative literature review based on the analysis of scientific articles published from 2009 to 2022 in PubMed on sleep deprivation and suicidal behavior. Results: The results certainly showed that quality and the minimum amount needed of sleep, when altered, interferes negatively in the individual's daily life, compromising social aspects significantly, leading to a higher incidence of disorders and acute and chronic diseases, such as schizophrenia , depression, anxiety, Alzheimer's and Parkinson's,increasing the risk of infectious diseases, cardiovascular diseases, cancer suggesting that the impact of the sleep-wake cycle on anatomy physiology is significant. Conclusion: The study showed that establishing a causal relationship between sleep and mood becomes indispensable to contribute to the development of conventional interventions to promote earlier approaches to sleep and mental health. It was also able to contemplate that sleep disturbance presents itself as a factor, worthy of incorporation into standardized frameworks, for suicide risk assessment and a growing body of research suggests that sleep complaints may be associated with an increased risk of suicidal ideation, suicide attempts and death by suicide, concluding that suicide is largely influenced by changes in the circadian cycle. ‎

P051 Associations between Chronotype and Symptoms of Depression in Patients attending an Outpatient Sleep Clinic

Abstract Introduction Chronotype (or morningness-eveningness), individuals’ time-of-the-day preference for activity, has been associated with depressive symptoms. This cross-sectional study examined the association between chronotype and symptoms of depression in outpatients attending a sleep disorders clinic. Method The sample included individuals attending an outpatient sleep disorders clinic and provided opt-out consent for their data to be used for research purposes. Individuals included in the analyses provided demographic data, their typical weekly total sleep time (TST), and complete responses prior to treatment on the reduced Morningness-Eveningness Questionnaire (rMEQ; for chronotype), and the PROMIS depression scale. Results A total of 1641 (44.5% female, Mage = 45.20 years, SDage = 16.06 years) participants were included. On average, the sample scored intermediate chronotype (M = 14.73, SD = 4.35) and higher depressive symptom scores that were half a standard deviation higher compared to community norms (M = 55.80, SD = 10.01). Multiple linear regression controlling for age, sex, and TST showed that greater eveningness preferences predicted higher symptoms of depression, p&amp;lt;0.01, explaining 2.76% additional variance in depression scores above that of the covariates. Discussion Overall, sleep clinic outpatients had an intermediate chronotype and above average depressive symptoms. The findings are consistent with existing literature in other populations indicating that eveningness may be a risk factor for greater symptoms of depression. Future studies need to explore whether interventions to alter chronotype may benefit symptoms of depression in individuals with sleep complaints.

P030 Understanding the relationships between sleep quality, and depression and anxiety in neurotrauma: A scoping review.

Abstract Introduction Sleep problems, depression, and anxiety are highly prevalent following a spinal cord injury (SCI) and traumatic brain injury (TBI) and may worsen functional outcomes and quality of life. This scoping review examined the existing literature to understand the relationships between sleep quality, depression, and anxiety in people with SCI and TBI, and to identify gaps in the literature. Methods A systematic search of seven databases was conducted. The findings of 30 eligible studies reporting associations between sleep quality and depression and/or anxiety following SCI or TBI were synthesised. Results The included studies were mostly cross-sectional and employed a range of subjective and objective measures of sleep quality. Poor subjective sleep quality and insomnia tended to be significantly associated with increased levels of depression and/or anxiety, but no such associations were reported when sleep quality was measured objectively. Two longitudinal studies observed worsening depressive symptoms over time were related to insomnia and persistent sleep complaints. Two interventional studies found that treating sleep problems improved symptoms of depression and anxiety. Discussion The findings of this review suggest that sleep and psychopathology are related in people with neurotraumatic injuries. This has important therapeutic implications, as individuals may benefit from therapy targeting both sleep and psychological issues. More longitudinal and interventional studies are warranted to further understand the direction and strength of the relationships, and how they impact patient outcomes.

Ketogenic diet may improve sleep quality and daytime somnolence in patients affected by multiple sclerosis. Results of an exploratory study

Objective/backgroundPatients with multiple sclerosis (MS) frequently report sleep complaints. The ketogenic diet (KD) is safe and tolerable in MS patients. Our aim was: 1) to investigate the effects of KD on sleep complaints in patients affected by relapsing-remitting MS and 2) to verify if sleep changes can positively impact on psychological status and quality of life (QoL) in these patients. Patients/methodsFrom January 2020 to November 2022, we consecutively enrolled 21 non-disabled or minimally disabled MS patients. We collected information regarding: 1) anthropometric measures; 2) psychological status by the Depression Anxiety Stress Scale-21; 3) QoL by the Multiple Sclerosis Quality of Life-54 (MSQOL-54); 4) subjective sleep complaints, i.e. sleep quality, by the Pittsburgh Sleep Quality Index (PSQI), and excessive daytime sleepiness (EDS), by the Epworth Sleepiness Scale (ESS). ResultsAfter 6 months of KD therapy, anthropometric measures considerably changed, psychological status significantly improved, and almost all the MSQOL-54 subscales ameliorated. Regarding sleep, we observed that the global PSQI (T0: 7.7 ± 3.1 versus T1: 4.4 ± 3.1, p = 0.002) and the ESS (T0: 7.5 ± 3.9 versus T1: 4.9 ± 3.2, p = 0.001) scores significantly decreased after KD therapy. At T1, only the global PSQI score was an independent predictor of anxiety, stress, and mental health. ConclusionsFor the first time, we demonstrated that KD may improve sleep complaints in MS patients. In addition, KD seems to have a positive impact on psychological status and QoL of MS patients, mainly through improving sleep quality. Further controlled studies with larger sample sizes are needed to confirm these preliminary results.

New insights and potential clinical implications of the odds ratio product.

The odds ratio product (ORP) is a continuous metric of sleep depth that ranges from 0 (very deep sleep) to 2. 5 (full wakefulness). Its advantage over the conventional method recommended by AASM is that it discloses different levels of stage wake (sleep propensity) and different sleep depths within the same sleep stage. As such, it can be used to identify differences in sleep depth between subjects, and in the same subjects under different circumstances, when differences are not discernible by conventional staging. It also identifies different sleep depths within stage rapid-eye-movement sleep, with possible implications to disorders during this stage. Epoch-by-epoch ORP can be displayed graphically across the night or as average values in conventional sleep stages. In addition, ORP can be reported as % of recording time in specific ORP ranges (e.g., deciles of the total ORP range) where it produces distinct distribution patterns (ORP-architecture) that have been associated with different clinical disorders and outcomes. These patterns offer unique research opportunities to identify different mechanisms and potential therapy for various sleep complaints and disorders. In this review I will discuss how ORP is measured, its validation, differences from delta power, and the various phenotypes, and their postulated mechanisms, identified by ORP architecture and the opportunities for research to advance management of sleep-disordered breathing, insomnia and idiopathic hypersomnia.