Intraindividual sleep variability and its association with insomnia identity and poor sleep

ObjectiveInsomnia identity refers to the conviction that one has insomnia, which can occur independently of poor sleep. Night-to-night variability in sleep (termed intraindividual variability [IIV]) may contribute to insomnia identity yet remain undetected via conventional mean analyses. This study compared sleep IIV across four subgroups: noncomplaining good sleepers (NG), complaining poor sleepers (CP), complaining good sleepers (CG), and noncomplaining poor sleepers (NP).MethodsThis study analyzed 14 days of sleep diary data from 723 adults. Participants were classified according to presence/absence of a sleep complaint and presence/absence of poor sleep. A 2 × 2 multivariate analysis of covariance (MANCOVA) was performed to explore differences on five measures of sleep IIV: intraindividual standard deviation in total sleep time (iSD TST), sleep onset latency (iSD SOL), wake after sleep onset (iSD WASO), number of nightly awakenings (iSD NWAK), and sleep efficiency (iSD SE).ResultsMANCOVA revealed significant main effects of poor sleep, sleep complaint, and their interaction on sleep IIV. Poor sleepers exhibited greater IIV across all sleep parameters compared to good sleepers. Similarly, individuals with a sleep complaint exhibited greater IIV compared to individuals with no complaint. The interaction revealed that iSD SOL was significantly greater among CP than NP, and iSD NWAK was significantly greater among CG than NG.ConclusionsGreater night-to-night variability in specific sleep parameters was present among complaining versus noncomplaining sleepers in good and poor sleep subgroups. These findings suggest certain aspects of sleep consistency may be salient for treatment-seeking individuals based on their quantitative sleep status.     

Cognitive performance and sleep quality in the elderly suffering from chronic insomnia. Relationship between objective and subjective measures

OBJECTIVE: The objective of the present study was to evaluate the relationship between objective and subjective sleep quality and objective and subjective evaluation of cognitive performance in older adults suffering of chronic insomnia (using or not benzodiazepines, BZs) or self-reported good sleepers. METHODS: Three groups of participants 55 years and older were evaluated: 20 insomnia sufferers using BZs chronically, 20 drug-free insomnia sufferers and 20 good sleepers. Objective sleep (PSG) and subjective sleep (sleep diaries, SD) were measured. Objective measures of cognitive performance (attention/concentration, verbal/visual memory, executive function and psychomotor speed) and subjective perception of daily performance were evaluated. RESULTS: Correlational analysis revealed that objective and subjective measures of daytime performance are differentially related to sleep quality for the three groups. An objective good night of sleep is associated with better cognitive performance in good sleepers and drug-free individuals. On the other hand, the impression of having slept well is related to better cognitive performance in good sleepers and chronic insomnia sufferers using BZs. CONCLUSION: Daytime performance and sleep quality are related, but differently so for a good sleeper, an insomnia sufferer without treatment, or one using BZs to alleviate sleep difficulties.     

Sleep quality during the COVID-19 pandemic: not one size fits all

BackgroundThe COVID-19 pandemic imposes a long period of stress on people worldwide and has been shown to significantly affect sleep duration across different populations. However, decreases in sleep quality rather than duration are associated with adverse mental health effects. Additionally, the one third of the general population suffering from poor sleep quality was underrepresented in previous studies. The current study aimed to elucidate effects of the COVID -19 pandemic on sleep quality across different levels of pre-pandemic sleep complaints and as a function of affect and worry.MethodParticipants (n = 667) of the Netherlands Sleep Registry (NSR) were invited for weekly online assessment of the subjective severity of major stressors, insomnia, sleep times, distress, depression, and anxiety using validated scales.AnalysisTo investigate the overall impact of the COVID-19 pandemic on the sleep quality of people with and without a history of insomnia, we performed a mixed model analysis using pre-pandemic insomnia severity, negative affect, and worry as predictors.ResultsThe effect of COVID -19 on sleep quality differs critically across participants, and depends on the pre-pandemic sleep quality. Interestingly, a quarter of people with pre-pandemic (clinical) insomnia experienced a meaningful improvement in sleep quality, whereas 20% of pre-pandemic good sleepers experienced worse sleep during the lockdown measures. Additionally, changes in sleep quality throughout the pandemic were associated with negative affect and worry.ConclusionOur data suggests that there is no uniform effect of the lockdown on sleep quality. COVID-19 lockdown measures more often worsened sleep complaints in pre-pandemic good sleepers, whereas a subset of people with pre-pandemic severe insomnia symptoms underwent a clinically meaningful alleviation of symptoms in our sample.     

'Young old' and 'old old' poor sleepers with and without insomnia complaints

OBJECTIVE: Sleep, psychological adjustment, health and insomnia complaints were examined in 277 community-dwelling seniors in order to identify characteristics that distinguish poor sleepers with complaints (likely to seek treatment) and those without complaints (unlikely to seek treatment). METHODS: Two weeks of sleep diaries and other sleep-related measures were collected. Young old (65-74 years) and old old (75+) participants were categorized as: good sleepers, poor sleepers with complaints (complainers), and poor sleepers without complaints (noncomplainers). RESULTS: In both age groups, complainers had poorer sleep than noncomplainers. Complainers also reported more depressive symptoms and had poorer health than noncomplainers. The old old slept longer each night, but took longer to fall asleep, napped more, and were more likely to complain of insomnia than the young old; otherwise, the young old/old old distinction did not explain sleep differences among the three types of sleepers. CONCLUSIONS: Implications for treating late-life insomnia include greater inclusion of the old old in treatment outcome research and more focus on the development of integrated intervention and prevention strategies that target health, depressive symptoms, and sleep.     

Hyperarousal and insomnia

Primary or psychophysiological insomnia has alternatively been viewed as either a predominantly psychological problem or as a predominantly physiological problem. Several early studies of patients were not able to document physiological differences, but more recent studies have found that many patients with primary insomnia take longer than control subjects to fall asleep on daytime nap tests despite feeling fatigued and they have elevated metabolic rate throughout both night and day. Other recent studies have found that increasing physiological arousal level for a week in normal sleepers produced the major secondary symptoms reported by insomniacs. In contrast, producing the disturbed sleep of insomniacs in a group of normal sleepers did not produce the typical pattern of secondary symptoms. Taken together, evidence is presented which supports the contention that primary insomniacs suffer from a disorder of hyperarousal and that the elevated arousal produces the poor sleep and other symptoms reported by patients. It is therefore suggested that new treatment strategies directed at reduction of arousal level be considered in these patients.     

Sleep movements and poor sleep in patients with non-specific somatic complaints--II. Affective disorders and sleep quality

Nocturnal motor activity of 67 poor sleepers referred to the Rehabilitation Research Centre (RRC) and of 16 healthy subjects were recorded to distinguish poor sleepers without affective disorders from those with affective disorders. All subjects slept on the static charge sensitive bed (SCSB) in a single room of the patient dormitory. All subjects filled out a sleep questionnaire about their subjective sleep quality. After comprehensive rehabilitation consultations the poor sleepers were divided into two subgroups: those with and those without affective disorders. Complaints about insomnia and sleep disorders distinguished poor sleepers from healthy controls but the subgroups of poor sleepers did not differ in the estimation of the quality of sleep. However, when the distribution of body movements through the night was considered, the dynamic of nocturnal motor activity typified poor sleepers with affective symptoms.     

How is good and poor sleep in older adults and college students related to daytime sleepiness, fatigue, and ability to concentrate?

We compared good sleepers with minimally and highly distressed poor sleepers on three measures of daytime functioning: self-reported fatigue, sleepiness, and cognitive inefficiency. In two samples (194 older adults, 136 college students), we tested the hypotheses that (1) poor sleepers experience more problems with daytime functioning than good sleepers, (2) highly distressed poor sleepers report greater impairment in functioning during the day than either good sleepers or minimally distressed poor sleepers, (3) daytime symptoms are more closely related to psychological adjustment and to psychologically laden sleep variables than to quantitative sleep parameters, and (4) daytime symptoms are more closely related to longer nocturnal wake times than to shorter sleep times. Results in both samples indicated that poor sleepers reported more daytime difficulties than good sleepers. While low- and high-distress poor sleepers did not differ on sleep parameters, highly distressed poor sleepers reported consistently more difficulty in functioning during the day and experienced greater tension and depression than minimally distressed poor sleepers. Severity of all three daytime problems was generally significantly and positively related to poor psychological adjustment, psychologically laden sleep variables, and, with the exception of sleepiness, to quantitative sleep parameters. Results are used to discuss discrepancies between experiential and quantitative measures of daytime functioning.     

Nocturnal cognitive arousal is associated with objective sleep disturbance and indicators of physiologic hyperarousal in good sleepers and individuals with insomnia disorder

BackgroundCognitive arousal is central to models of sleep disturbance and insomnia, but findings remain mixed regarding whether cognitive arousal is associated with objective sleep disturbance and physiologic hyperarousal. This study explored associations of objective nocturnal wakefulness and indicators of physiologic hyperarousal with cognitive arousal in healthy sleepers and individuals with insomnia.MethodsIn sum, 52 adults (51.9% women; 18 with insomnia disorder, 34 healthy sleepers) underwent two overnight polysomnography (PSG) studies (adaptation + baseline nights) and a multiple sleep latency test (MSLT). Baseline depression was assessed and presleep cognitive arousal and somatic arousal were recorded for each night. Multivariate regression was used to evaluate associations of PSG sleep parameters with insomnia, cognitive arousal, and somatic arousal.ResultsAnalyses showed that high levels of nocturnal cognitive arousal were associated with prolonged sleep latency, lower sleep efficiency, and shorter total sleep time by PSG on both nights. An association between nocturnal cognitive arousal and wake after sleep onset was observed on night one only. Moreover, greater nocturnal cognitive arousal was associated with greater likelihood of obtaining short sleep and with longer MSLT sleep latencies. Insomnia diagnosis, depression, and somatic arousal were not associated with PSG sleep parameters or MSLT latency.ConclusionsHeightened cognitive arousal at night is linked to objective sleep disturbances and indicators of physiologic hyperarousal at night and during the day. For patients with insomnia, cognitive arousal may contribute to the 24-hr physiologic hyperarousal. Cognitive arousal may be a critical therapeutic target for severe or treatment-resistant sleep disturbance.     

Pre-sleep arousal and sleep quality during the COVID-19 lockdown in Italy

ObjectiveThe COVID-19 pandemic has strongly affected daily habits and psychological wellbeing, and many studies point to large modifications in several sleep and sleep-related domains. Nevertheless, pre-sleep arousal during the pandemic has been substantially overlooked. Since hyperarousal represents one of the main factors for the development and the perpetuation of chronic insomnia disorder, the assessment of variables associated with high levels of pre-sleep arousal during the pandemic is clinically relevant. The study aimed to assess the prevalence and predictors of perceived sleep quality and pre-sleep arousal in an Italian sample during the COVID-19 lockdown.MethodsWe used an online survey to collect self-reported sociodemographic, environmental, clinical, sleep, and sleep-related data. Our final sample included 761 participants.ResultsBeyond a high frequency of poor sleep quality, depressive and stress symptoms, our results show that almost half of the sample suffered from clinically relevant levels of at least one component (ie, cognitive, somatic) of pre-sleep arousal. Subjects with greater pre-sleep arousal exhibited poorer sleep quality. Also, sleep quality was strongly associated with somatic and cognitive pre-sleep arousal. Regarding the predictors of sleep and sleep-related measures, depressive and event-related stress symptoms were the main factors associated with both poor sleep quality and pre-sleep arousal components. Moreover, specific sociodemographic and environmental variables were uniquely related to sleep quality, cognitive or somatic pre-sleep arousal.ConclusionsThese findings suggest that the assessment of specific sleep-related factors (ie, pre-sleep arousal), together with more global measures of sleep quality, may be crucial to depict the complex impact of the pandemic on sleep, and to help prevent and counteract the spread of insomnia symptoms.