Pre-sleep affect predicts subsequent REM frontal theta in nonlinear fashion.

Pre-sleep affect is thought to influence sleep, but associations with both sleep architecture and the electroencephalographic (EEG) power spectrum are mixed. In this pre-registered study, we assessed negative valence and arousal 1 h pre-sleep in 52 adults drawn from the community, then recorded one night of polysomnography (PSG) in participants' own homes. Pre-sleep affect was not associated with nonrapid eye movement (NREM) or rapid eye movement (REM) sleep architecture parameters, but we did observe inverted U-shaped relationships between both negative valence and arousal and REM frontal theta power, such that theta power was highest at moderate negative valence and arousal, and lowest at either affective extreme. When entered into a model together, both valence and arousal accounted for independent variance. Secondary analyses revealed a similar quadratic association with pre-sleep positive valence, suggesting a nonspecific effect of pre-sleep valence on REM frontal theta. Robustness checks confirmed that effects were not explained by homeostatic sleep pressure or sleep timing. Our results suggest that mixed findings in the literature may reflect different ends of a quadratic function, underscoring the importance of assessing how different components of pre-sleep affect relate to sleep.

Insomnia-related interpretational bias is associated with pre-sleep worry.

Cognitive models of insomnia highlight the role of biased cognition in sleep-related information, which is proposed to underlie pre-sleep worry, which in turn results in both subjective and objective sleep deficits. To test this hypothesis, the current study investigated interpretational bias, which is a tendency to interpret ambiguous stimuli in a threat-related (here: insomnia-related) manner. We specifically hypothesized that interpretational bias would be associated with (a) pre-sleep worry and (b) poor subjective and objective sleep. Interpretational bias was measured using the ambiguous scenario task, in which participants (n = 76, community sample) were presented with two types of scenarios (insomnia and anxiety related) that could be alternatively interpreted in a neutral manner. Participants additionally completed questionnaires to assess global sleep quality and pre-sleep worry, which were followed by 1-week sleep assessments (via diaries and actigraphy) to estimate specific, daily subjective and objective sleep parameters. The results showed that insomnia-related (but not anxiety-related) interpretational bias was positively associated with pre-sleep worry as well as overall sleep quality. However, these associations could be explained by general trait anxiety. We also found no connection to specific subjective or objective parameters of daily sleep, such as sleep onset latency. These findings support the cognitive-hyperarousal mechanism, where biased cognition (together with trait anxiety) underlies pre-sleep worry. The association with overall sleep quality, but not with specific, daily subjective or objective sleep parameters, may suggest that interpretational bias is specifically relevant for how individuals judge and describe their sleep quality.

Development and Validity of the Japanese Version of the Pre-Sleep Arousal Scale.

Hyperarousal, defined as increased levels of cortical activity and cognitive-emotional reactivity induced by stress, is suggested to be a key factor in insomnia. In particularly, pre-sleep arousal constitutes one of the major features of insomnia. The Pre-Sleep Arousal Scale is the best-known measure used to evaluate pre-sleep arousal. However, a well-validated Japanese version of the scale (PSAS-J) has not yet been established. The aim of this research was to develop and validate such a scale. A cross-sectional questionnaire-based study was conducted via the internet. In total, 237 of 300 participants (mean age 43.28 ± 11.19 years) completely responded to the questionnaires as followed: the PSAS-J, the Insomnia Severity Index, Ford Insomnia Response to Stress Test, and Dysfunctional Beliefs and Attitudes about Sleep Scale. In addition, the participants were divided into two groups: insomniacs and normal sleepers. As a result, the PSAS-J had a two-factor structure similar to that of the original version, i.e., somatic and cognitive arousal subscales. The internal consistency (α = 0.85 to 0.90) and test-retest reliability (r = 0.67 to 0.78) were high. Correlations between the PSAS-J and the above-mentioned scales ranged from 0.35 to 0.53. Discriminant validity showed that the PSAS-J was distinct from the Ford Insomnia Response to Stress Test and Dysfunctional Beliefs and Attitudes about Sleep Scale. The PSAS-J scores were significantly higher in insomniacs than in normal sleepers. Our results suggest that the PSAS-J has high reliability and validity and that this scale is adequate for assessing pre-sleep arousal.

Pilot testing a stretching regimen for prevention of night time nocturnal leg cramps.

Nocturnal leg cramps (NLC) are painful, involuntary muscle contractions that affect the quality of sleep. The aim of this study was to examine the feasibility and effectiveness of a stretching regimen in frail older adults aged over 75 years with NLC. The experimental group (n = 15) received an intervention, which they were instructed to perform three daily exercises to stretch the calves and hamstrings. After six weeks, frequency and pain intensity of NLC were both significantly decreased in the experimental group compared to the control group. A paired samples t-test reveals a statistically significant decrease in cramp frequency (t = 2.2, df 28, P = 0.04) and cramp intensity (t = 2.7, df 28, P = 0.01). Therefore, a six-week stretching regimen is likely to reduce the frequency and pain intensity of NLC in frail older adults aged over 75 years.

Am I (hyper)aroused or anxious? Clinical significance of pre-sleep somatic arousal in young adults.

Self-reported somatic arousal remains a challenging clinical construct, particularly because only a subset of patients report symptoms such as racing heart, palpitations or increased body temperature interfering with their sleep. It is unclear whether self-reported somatic arousal is a marker of hyperarousal or co-morbid clinical anxiety in individuals with insomnia. Participants included 196 young adults aged 20.2 ±â€…1.0 years old who were predominantly females (75%). About 39% of the sample reported subthreshold insomnia, and about 8% reported clinically significant insomnia, based on their Insomnia Severity Index. Participants completed the Pre-Sleep Arousal Scale, Beck Anxiety Inventory, Beck Depression Inventory, Arousal Predisposition Scale, and Ford Insomnia Response to Stress Test. Multivariable stepwise regression assessed which factors were independently associated with pre-sleep cognitive (Pre-Sleep Arousal Scale-Cognitive) and somatic (Pre-Sleep Arousal Scale-Somatic) arousal. Receiver-operating characteristic analysis assessed the predictive value to identify clinically significant anxiety (Beck Anxiety Inventory ≥ 20), insomnia (Insomnia Severity Index ≥ 15) and arousability (Arousal Predisposition Scale ≥ 32). Beck Anxiety Inventory (ß = 0.42) was the best single correlate of Pre-Sleep Arousal Scale-Somatic, while Insomnia Severity Index (ß = 0.33) was of Pre-Sleep Arousal Scale-Cognitive. A Pre-Sleep Arousal Scale-Somatic score of 12 or more identified those with clinically significant anxiety with 65% specificity and 65% sensitivity, while a cut-off score of 14 increased its sensitivity (86%). Self-reported pre-sleep somatic arousal may be an index of co-morbid clinical anxiety in individuals with insomnia. These findings aid clinicians with assessment and treatment, particularly in the absence of clinical guidelines indicating when somatically focused relaxation techniques should be included as part of multicomponent cognitive behavioural treatment of insomnia.

Self-reported sleep quantity, quality and sleep hygiene in elite athletes.

Sleep is essential for recovery and performance in elite athletes. While actigraphy-based studies revealed suboptimal sleep in athletes, information on their subjective experience of sleep is scarce. Relatively unexplored is also the extent to which athletes' sleep is adversely affected by environmental conditions and daytime behaviours, that is sleep hygiene. This study aimed to provide insight in sleep quantity, quality and its putative association with sleep hygiene. Participants were 98 elite (youth) athletes competing at the highest (inter-)national level. Sleep quantity, quality and sleep hygiene were assessed once covering a 1-month period by using established (sub)clinical questionnaires, and repeatedly during 7 consecutive days. Sleep quality was generally healthy, although 41% of all athletes could be classified as 'poor sleeper', and 12% were identified as having a sleep disorder. Daily self-monitoring revealed sleep durations of 8:11 ± 0:45 h, but elevated wake after sleep onset of 13 ± 19 min. Sleep quality, feeling refreshed, and morning vigor were moderate at best. Regarding sleep hygiene, general measures revealed irregular sleep-wake patterns, psychological strain and activating pre-sleep behaviours. At the daily level, blue-light exposure and late-evening consumption of heavy meals were frequently reported. General sleep hygiene revealed significant associations with sleep quality (0.45 < r > 0.50; P < 0.001). Results indicate that there is ample room for optimization, specifically in onset latency and in wake after sleep onset. Subtle improvements in sleep seem possible, and optimizing sleep hygiene, such as regular sleep-wake patterns and reducing psychological strain, may facilitate this sleep upgrading process.

Who is sleepier on the night shift? The influence of bio-psycho-social factors on subjective sleepiness of female nurses during the night shift.

Sleepiness is a common complaint during the night shift and may impair performance. The current study aims to identify bio-psycho-social factors associated with subjective sleepiness during the night shift. Ninety-two female nurses working rotating shifts completed a sociodemographic questionnaire, the Munich ChronoType Questionaire for shift workers, the Pittsburg Sleep Quality Index, and the Pre-sleep Arousal Scale. Subjective sleepiness was measured hourly during two night shifts using the Karolinska Sleepiness Scale, and activity monitors assessed sleep duration 24-h before each shift. Findings showed that increased sleepiness was associated with increased age in nurses with early chronotypes and with more children. High cognitive pre-sleep arousal, but not sleep, was associated with increased sleepiness, especially in late chronotypes. The impact of bio-psycho-social factors on night shift sleepiness is complex, and depends on mutual interactions between these factors. Nurses most prone to increased sleepiness must develop personal strategies for maintaining vigilance on the night shift. Practitioner Summary: This study aims to identify bio-psycho-social factors associated with subjective sleepiness of female nurses during the night shift. Increasing sleepiness was associated with increased age in nurses with early chronotypes and with more children. Increased cognitive pre-sleep arousal, but not sleep, was associated with increased sleepiness, especially in late chronotypes.

Cognitive processes in comorbid poor sleep and chronic pain.

We examined the unique and shared contributions of pain catastrophizing, cognitive pre-sleep arousal, and somatic pre-sleep arousal, to the prediction of insomnia severity in chronic pain. Forty-eight adults with chronic pain completed self-report measures of these study variables, health, and mood. Hierarchical regression showed that pain catastrophizing accounted for unique variance in insomnia severity, independent of pain intensity, depression, restless legs symptoms, and demographics. However, when cognitive and somatic pre-sleep arousal were also taken into account, the significance of cognitive pre-sleep arousal rendered pain catastrophizing non-significant. We identify research and clinical implications of this study.

Access to a pre-sleep protein snack increases daily energy and protein intake in surgical hospitalized patients.

BACKGROUND & AIM: In hospitalized patients, daily protein intake remains far below WHO requirements for healthy adults (0.8 g·kg-1·d-1) as well as ESPEN guidelines for patients (1.2-1.5 g·kg-1·d-1). Providing access to a pre-sleep protein dense snack between dinner and going to bed may serve as a great opportunity to increase daily energy and protein intake in hospitalized patients. However, it remains to be assessed whether protein provision prior to sleep effectively increases protein intake, or may reduce food intake throughout the remainder of the day(s). The present study evaluated the impact of giving access to a pre-sleep snack on daily energy and protein intake in patients throughout their hospitalization. METHODS: Patients admitted to the surgical wards of the Maastricht University Medical Centre+ were randomly allocated to usual care (n = 51) or given access to a pre-sleep snack (n = 50). The pre-sleep snack consisted of 103 g cheese cubes (30 g protein) provided between 7:30 and 9:30 PM, prior to sleep. All food provided and all food consumed was weighed and recorded throughout (2-7 days) hospitalization. Daily energy and protein intake and distribution were calculated. Data were analyzed by independent T-Tests with P < 0.05 considered as statistically significant. RESULTS: Daily energy intake was higher in the pre-sleep group (1353 ± 424 kcal d-1) when compared to the usual care group (1190 ± 402 kcal·d-1; P = 0.049). Providing patients access to a pre-sleep snack resulted in a 17% (11 ± 9 g) higher daily protein intake (0.81 ± 0.29 g·kg-1·d-1) when compared to the usual care group (0.69 ± 0.28 g·kg-1·d-1; P = 0.045). Protein intake at breakfast, lunch, and dinner did not differ between the pre-sleep and usual care groups (all P > 0.05). CONCLUSION: Providing access to a pre-sleep protein snack, in the form of protein dense food items such as cheese, represents an effective dietary strategy to increase daily energy and protein intake in hospitalized patients. Patients consuming pre-sleep protein snacks do not compensate by lowering energy or protein intake throughout the remainder of the days. Pre-sleep protein dense food provision should be implemented in hospital food logistics to improve the nutritional intake of patients. TRIAL REGISTER NO: NL8507 (https://trialsearch.who.int/).

The psychometric properties of the Turkish version of the Pre-sleep Arousal Scale.

Purpose: The aim of the present study was to examine the psychometric properties of the Turkish version of the Pre-sleep Arousal Scale (PSAS), which measures pre-sleep arousal, a significant predictor of insomnia symptoms. Methods: 651 participants were recruited via social media and the Internet. Confirmatory factor analysis was conducted in the total sample (65.28% females; Mage1 = 28.09 ± 14.00). Convergent, divergent, incremental, and known-groups validity and internal consistency coefficients were assessed in a subsample of 556 participants (62.77% females; Mage2 = 29.25 ± 14.81). A second separate sample of 88 participants (80.68% females; Mage3 = 22.19 ± 4.98) was used to evaluate three-week test-retest reliability. Results: The results of factor analysis confirmed the two-factor structure of the Turkish PSAS with cognitive (PSAS-C) and somatic (PSAS-S), similar to the original scale. The correlations of the PSAS with convergent and divergent measures showed that the Turkish form had good convergent and acceptable divergent validity. PSAS-C and PSAS-S were able to explain an 18% additional variance in insomnia severity beyond depression and anxiety, an 18% additional variance in depression beyond insomnia severity, and a 35% additional variance in anxiety beyond insomnia severity. Moreover, insomnia patients had significantly higher PSAS-C and PSAS-S scores than good sleepers. Finally, the PSAS, PSAS-C, and PSAS-S had satisfactory internal consistency coefficients (α = 0.92, 0.91, and 0.86, respectively) and three-week test-retest correlations (ICC = 0.82, 0.82, and 0.71, respectively). Conclusion: The Turkish form of the PSAS was a valid and reliable measure of pre-sleep arousal and can be utilized in sleep studies. Supplementary Information: The online version contains supplementary material available at 10.1007/s41105-023-00483-z.

Rasch analysis of the pre-sleep arousal scale in patients with acute insomnia disorder.

BACKGROUND: Hyperarousal plays an essential role in the initiation and maintenance of insomnia, highlighting the need for a tool that measure the hyperarousal state during the early course of insomnia. Pre-sleep Arousal Scale (PSAS) is a self-report questionnaire to evaluate subjective pre-sleep arousal of insomnia. The aim of this study was to examine the psychometric properties of the PSAS among patients with acute insomnia disorder (AID) using Rasch analysis. METHODS: Totally 170 patients with AID from 31 public hospitals in China were recruited and completed the test. The psychometric properties of the PSAS were tested using Rasch analysis by Winsteps v5.4.1.0, including unidimensionality, local item independence, item fit, category diagnostics, reliability, item-person maps and differential item functioning (DIF) by age and gender. RESULTS: According to Rasch analysis, somatic and cognitive subscales were unidimensional and basically demonstrated good item-fit statistics. 4-point Likert scale may be more appropriate for PSAS. All items have a good reliability and separation. No gender and age bias were detected for the scale. However, the person arousal level is not well matched to item difficulty. CONCLUSION: The present study further reveals appropriate psychometric properties of the PSAS in patients with AID and provides suggestions for refinements and supplements to the PSAS.

Pre-Sleep Arousal Scale (PSAS): Translation and Evaluation of Its Psychometric Properties in an Arabic Version.

Purpose: The Pre-Sleep Arousal Scale (PSAS) is a well-recognized instrument utilized for measuring cognitive and somatic arousal before sleep. Although the PSAS is useful, an Arabic version of the scale has not yet been developed and validated. The current study aimed to translate the PSAS into Arabic language and evaluate its psychometric properties, such as reliability and validity, in an Arabic-speaking population. Patients and Methods: A cross-sectional survey was conducted with 438 participants who completed the Arabic version of the PSAS, along with other validated measures of insomnia, anxiety, and sleep effort. Results: The results indicated that the Arabic version of the PSAS maintained the original scale's two-factor structure. The factor loadings for PSAS-Cognitive ranged from 0.57 to 0.75, and for PSAS-Somatic, from 0.45 to 0.70, with all loadings being statistically significant (p < 0.001). The Arabic version of the PSAS exhibited high internal consistency (McDonald's ω = 0.86; Cronbach's α = 0.86; Guttman's λ2 = 0.86; Greatest Lower Bound = 0.90) and test-retest reliability (ICC = 0.88) over two weeks. The PSAS demonstrated good concurrent and convergent validity. We documented significant large differences between individuals with "no insomnia" and those with "insomnia" symptoms across cognitive, somatic, and total pre-sleep arousal (all p <0.001). The insomnia group consistently scored higher scores for PSAP and its subscales. Conclusion: These findings suggest that the Arabic version of the PSAS is a reliable and valid tool for assessing pre-sleep arousal in Arabic-speaking individuals.

Executive dysfunction, negative pre-sleep cognitions, and sleep problems: examining a cyclical model.

Sleep is integral to cognitive functioning, and disturbances in sleep patterns can impair cognition. This study investigated the relationships between executive functions, sleep problems, and negative pre-sleep cognitions, proposing a model for their interaction. We assessed 107 adults using the Bedtime Counterfactual Processing Questionnaire and the Glasgow Content of Thoughts Inventory for negative pre-sleep cognitions, the Insomnia Severity Index and the Pittsburgh Sleep Quality Index for sleep problems, and the Free Research Executive Evaluation test battery for executive functions. Regression and mediation analyses were conducted to examine both direct and indirect relationships between these variables. Higher executive functions were associated with fewer negative pre-sleep cognitions, which in turn predicted fewer sleep problems. However, the anticipated direct effect of sleep problems on executive functioning was not supported, indicating a more complex interplay. Notably, pre-sleep cognition mediated the relationship between executive functions and sleep problems, indirectly affecting sleep problems through its connection with executive functions. While the findings support the mediation model of executive functions, negative pre-sleep cognitions, and sleep problems, the proposed cyclical model was not fully substantiated. This suggests that additional factors may influence the dynamics of this relationship, offering potential avenues for future research and interventions targeting sleep disorders and cognitive well-being enhancement.

A Comprehensive Assessment of Bedtime Routines and Strategies to Aid Sleep Onset in College Students: A Web-Based Survey.

College students often experience sleep-wake alterations. Different factors can contribute to insomnia symptoms in this population. The present study aims at investigating pre-sleep behaviours and strategies used to aid sleep onset in young college students and their association with insomnia symptoms. A total of 548 Italian college students (mean age = 23.48 years, range = 19-30 years, 80.5% female) completed a web-based survey on pre-sleep behaviours and sleep-onset facilitators, insomnia symptoms and sleep hygiene, anxiety and depression, and coping strategies. The use of electronic devices at bedtime and as a sleep-onset facilitator was predominant. Students using specific behaviours as sleep-onset facilitators were characterised by more psychological difficulties and poorer sleep. In multivariable linear regression analysis, the frequency of using medications and melatonin, regardless of motivations, was associated with higher insomnia symptoms. The use of specific sleep-onset facilitators positively correlated with the severity of insomnia symptoms. Many students engage in behaviours that are considered sleep-interfering and that are often employed in an attempt to facilitate sleep onset without benefits. Overall, the motivational factors behind pre-sleep behaviours need to be addressed in preventive programs targeting young college students.

Cross-sectional analyses of factors associated with the presence and aggravation of chronic insomnia by symptom subtypes.

Aim: The aim of this study was to investigate the association of psychological and chronobiological factors with the presence and severity of chronic insomnia by symptom subtypes and their impacts on daytime dysfunctions. Methods: Participants of the present web-based epidemiological study were classified as follows: difficulty initiating sleep (DIS) (n = 91); difficulty maintaining sleep (DMS) (n = 13); early morning awakening (EMA) (n = 48); DIS + DMS (n = 67); DIS + EMA (n = 23); DMS + EMA (n = 24); triplet of DIS, DMS, and EMA symptoms (TRP) (n = 69); and normal sleepers (n = 4590). The Insomnia Severity Index (ISI), Hospital Anxiety and Depression Scale (HADS), Munich Chronotype Questionnaire (MCTQ), insomnia-related psychological measures (including the Ford Insomnia Response to Stress Test [FIRST] and the Dysfunctional Beliefs and Attitudes about Sleep Scale [DBAS]), and the cognitive and somatic domains of the Pre-Sleep Arousal Scale (PSAS) were evaluated. Results: The presence of DIS and DIS + DMS were significantly associated with an evening preference, and EMA and EMA + DMS with a morning preference, while TRP showed no significant association with either chronotype. The increase in DBAS scores was associated with higher ISI scores in all subtypes. Meanwhile, the associations of each psychological measure varied among insomnia subtypes, with the association of PSAS cognitive arousal to DIS and PSAS somatic arousal to both DMS + EMA and TRP. Pathological HADS score was associated with all subtypes. Conclusion: Chronotypes may be associated with the presence of some insomnia subtypes; however, only psychological factors were speculated to contribute to the aggravation of all subtypes. All insomnia subtypes possibly contribute to the formation of depression.

Neurophysiological and behavioral synchronization in group-living and sleeping mice.

Social interactions profoundly influence animal development, physiology, and behavior. Yet, how sleep-a central behavioral and neurophysiological process-is modulated by social interactions is poorly understood. Here, we characterized sleep behavior and neurophysiology in freely moving and co-living mice under different social conditions. We utilized wireless neurophysiological devices to simultaneously record multiple individuals within a group for 24 h, alongside video acquisition. We first demonstrated that mice seek physical contact before sleep initiation and sleep while in close proximity to each other (hereafter, "huddling"). To determine whether huddling during sleep is a motivated behavior, we devised a novel behavioral apparatus allowing mice to choose whether to sleep in close proximity to a conspecific or in solitude, under different environmental conditions. We also applied a deep-learning-based approach to classify huddling behavior. We demonstrate that mice are willing to forgo their preferred sleep location, even under thermoneutral conditions, to gain access to social contact during sleep. This strongly suggests that the motivation for prolonged physical contact-which we term somatolonging-drives huddling behavior. We then characterized sleep architecture under different social conditions and uncovered a social-dependent modulation of sleep. We also revealed coordination in multiple neurophysiological features among co-sleeping individuals, including in the timing of falling asleep and waking up and non-rapid eye movement sleep (NREMS) intensity. Notably, the timing of rapid eye movement sleep (REMS) was synchronized among co-sleeping male siblings but not co-sleeping female or unfamiliar mice. Our findings provide novel insights into the motivation for physical contact and the extent of social-dependent plasticity in sleep.

Transient insomnia versus chronic insomnia: a comparison study of sleep-related psychological/behavioral characteristics.

OBJECTIVES: Vulnerability to transient insomnia is regarded as a predisposing factor for chronic insomnia. However, most individuals with transient insomnia do not develop chronic insomnia. The current study investigated the differential contributing factors for these two conditions to further the understanding of this phenomenon. METHOD: Chronic insomnia patients and normal sleepers with high and low vulnerability to transient insomnia completed measures of pre-sleep arousal, dysfunctional sleep beliefs, and sleep-related safety behaviors. RESULTS: Both cognitive and somatic pre-sleep arousals were identified as significant predictors for transient insomnia. Dysfunctional beliefs regarding worry about insomnia and cognitive arousal were predictors for chronic insomnia. Sleep-related safety behavior, although correlated with insomnia severity, was not a significant predictor for both conditions. CONCLUSIONS: Dysfunctional beliefs associated with worry and losing control over sleep are the most critical factors in differentiating chronic insomnia from transient insomnia. These factors should be addressed to help prevent individuals with high sleep vulnerability from developing chronic sleep disturbance.

Insomnia is a key risk factor for persistent anxiety and depressive symptoms: A 12-month longitudinal cohort study during the COVID-19 pandemic.

BACKGROUND: Insomnia is a risk factor for affective disorders. This study examined whether individuals with insomnia symptoms early in the pandemic, either pre-existing or new-onset, were more vulnerable to anxiety and depressive symptoms over time than those who maintained normal sleep. Additionally, sleep-related factors such as pre-sleep arousal were assessed for their influence on clinically significant anxiety and depression risk. METHODS: Using a global online survey with 3-, 6-, and 12-month follow-ups between April 2020 and May 2021, data from 2069 participants (M = 46.16 ± 13.42 years; 75.3 % female) with pre-existing, new-onset, or no insomnia symptoms was examined using mixed-effects and logistic regression models. RESULTS: New-onset and pre-existing insomnia predicted persistent anxiety and depressive symptoms longitudinally (p's < 0.001), over other known risk factors, including age, sex, and previous psychiatric diagnoses. Anxiety and depressive symptoms in both insomnia groups remained above clinically significant thresholds at most time points, whereas normal sleepers remained subclinical. Pre-sleep arousal was found to increase the risk of clinically significant anxiety (OR = 1.05) and depressive symptoms (OR = 1.09) at 12-months. Sleep effort contributed to anxiety (OR = 1.06), whereas dysfunctional sleep-related beliefs and attitudes predicted clinically significant depression (OR = 1.22). LIMITATIONS: Insomnia group categorization was based on self-report at baseline supported by a validated measure. High participant attrition was observed at 3-months (53 %; n = 971), but retention remained steady till 12-months (63 %, n = 779). CONCLUSIONS: Insomnia is a modifiable risk factor for persistent anxiety and depressive symptoms that needs to be addressed in mental healthcare. Additionally, pre-sleep arousal may be an important transdiagnostic process linking insomnia with affective disorders.

The influence of cognitive activity on subsequent daytime nap: A deep neural network model based on sleep spindles.

OBJECTIVES: Understanding the influence of cognitive activity on subsequent sleep has both theoretical and applied implications. This study aims to investigate the effect of pre-sleep cognitive activity, in the context of avoiding emotional interference, on macro-sleep and sleep spindles. METHODS: In a within-subjects design, participants' sleep electroencephalography was collected in both the with and without pre-sleep cognitive activity conditions. Subsequent macro-sleep (i.e., sleep stage distribution and sleep parameters) and spindle characteristics (i.e., density, amplitude, duration, and frequency) were analyzed. In addition, a novel machine learning framework (i.e., deep neural network, DNN) was used to discriminate between cognitive activity and control conditions. RESULTS: There were no significant differences in macro-sleep and sleep spindles between the cognitive activity and control conditions. Spindles-based DNN models achieved over 96% accuracy in differentiating between the two conditions, with fast spindles performing better than full-range and slow spindles. CONCLUSIONS: These results suggest a weak but positive effect of pre-sleep cognitive activity on subsequent sleep. It sheds light on a possible low-cost and easily accessible sleep intervention strategy for clinical and educational purposes.

Pre-sleep feeding, sleep quality, and markers of recovery in division I NCAA female soccer players.

Pre-sleep nutrition habits in elite female athletes have yet to be evaluated. A retrospective analysis was performed with 14 NCAA Division I female soccer players who wore a WHOOP, Inc. band - a wearable device that quantifies recovery by measuring sleep, activity, and heart rate metrics through actigraphy and photoplethysmography, respectively - 24 h a day for an entire competitive season to measure sleep and recovery. Pre-sleep food consumption data were collected via surveys every 3 days. Average pre-sleep nutritional intake (mean ± sd: kcals 330 ± 284; cho 46.2 ± 40.5 g; pro 7.6 ± 7.3 g; fat 12 ± 10.5 g) was recorded. Macronutrients and kcals were grouped into high and low categories based upon the 50th percentile of the mean to compare the impact of a high versus low pre-sleep intake on sleep and recovery variables. Sleep duration (p = 0.10, 0.69, 0.16, 0.17) and sleep disturbances (p = 0.42, 0.65, 0.81, 0.81) were not affected by high versus low kcal, PRO, fat, CHO intake, respectively. Recovery (p = 0.81, 0.06, 0.81, 0.92), RHR (p = 0.84, 0.64, 0.26, 0.66), or HRV (p = 0.84, 0.70, 0.76, 0.93) were also not affected by high versus low kcal, PRO, fat, or CHO consumption, respectively. Consuming a small meal before bed may have no impact on sleep or recovery.