Sleep quality in the general population: psychometric properties of the Pittsburgh Sleep Quality Index,derived from a German community sample of 9284 people

BackgroundThe Pittsburgh Sleep Quality Index (PSQI) is frequently used to assess sleep problems in patients. The aim of this study was to provide reference values for this questionnaire, to test psychometric properties, and to analyze associations with psychological, sociodemographic, and behavioral factors.MethodsA German community sample comprising 9284 adult residents (aged 18–80 years) was surveyed using the PSQI and several other questionnaires.ResultsAccording to the generally accepted cut-off (PSQI > 5), 36% of the general population slept badly. Females reported significantly more sleep problems than males (mean scores: M = 5.5 vs. M = 4.4, respectively; effect size d = 0.35), but there was no linear association between age and sleep quality. Sleep problems were correlated with fatigue, quality of life (physical as well as mental), physical complaints, anxiety, and lack of optimism. Sleep quality was also strongly associated with socioeconomic status, professional situation (poorest sleep quality in unemployed people), and obesity. In addition to the results of the PSQI total score, mean scores of specific components of sleep quality were presented (sleep latency, sleep duration, and use of sleep medication).ConclusionThe PSQI proved to be a suitable instrument for measuring sleep quality. Gender differences, psychological factors, and obesity should be taken into account when groups of patients are compared with respect to sleep problems.     

Clinical significance of mobile health assessed sleep duration and variability in bipolar disorder

ObjectiveSleep disturbances are prevalent, persistent, and impairing features of bipolar disorder. However, the near-term and cumulative impact of the severity and variability of sleep disturbances on symptoms and functioning remains unclear. We examined self-reported daily sleep duration and variability in relation to mood symptoms, medication adherence, cognitive functioning, and concurrent daily affect.MethodsForty-one outpatients diagnosed with bipolar disorder were asked to provide daily reports of sleep duration and affect collected via ecological momentary assessment with smartphones over eleven weeks. Measures of depressive and manic symptoms, medication adherence, and cognitive function were collected at baseline and concurrent assessment of affect were collected daily. Analyses examined whether sleep duration or variability were associated with baseline measures and changes in same-day or next-day affect.ResultsGreater sleep duration variability (but not average sleep duration) was associated with greater depressive and manic symptom severity, and lower medication adherence at baseline, and with lower and more variable ratings of positive affect and higher ratings of negative affect. Sleep durations shorter than 7–8 h were associated with lower same-day ratings of positive and higher same-day ratings of negative affect, however this did not extend to next-day affect.ConclusionsGreater cumulative day-to-day sleep duration variability, but not average sleep duration, was related to more severe mood symptoms, lower self-reported medication adherence and higher levels of negative affect. Bouts of short- or long-duration sleep had transient impact on affect. Day-to-day sleep variability may be important to incorporate into clinical assessment of sleep disturbances in bipolar disorder.     

Associations between poor sleep quality and different measures of obesity

ObjectivePoor sleep may be a risk factor for obesity. Previous studies have mainly investigated the effects of sleep duration on body mass index, but research considering overall sleep quality and other anthropometric measures is scarce. The aim of this study was to examine the association between sleep quality and different measures of obesity (general obesity, abdominal obesity, body composition) in a population-based sample of adults.MethodsThe study included 753 participants aged 35–65 years from the BiDirect Study, conducted in Münster, Germany. Participants completed the Pittsburgh Sleep Quality Index (PSQI) on sleep characteristics. Weight, height, and waist circumference were measured by trained study nurses. Body composition (fat mass and fat-free mass) was assessed using bioelectrical impedance analysis. The cross-sectional relationship between sleep quality and measures of obesity was investigated using logistic regression analysis.ResultsAmong the participants, 65.3% reported good (PSQI ≤ 5) and 34.7% poor (PSQI > 5) sleep quality. We observed a significant association of poorer sleep quality assessed by the continuous PSQI score with general obesity and high body fat (for both, odds ratio = 1.07, 95% confidence interval = 1.01–1.13), adjusted for socio-demographic and lifestyle factors. Further adjustment for depressive symptoms and somatic comorbidities attenuated the relationship. The observed association was mainly driven by the PSQI components sleep latency, sleep disturbances, and daytime dysfunction.ConclusionsThe present study suggests that poor sleep quality may predict obesity and high body fat mass among adults. However, a causal relationship still has to be confirmed by prospective studies with objective measurements of sleep and obesity.     

The relationship between sleep disturbance,symptoms and daytime functioning in psoriasis: a prospective study integrating actigraphy and experience sampling methodology

Objective/backgroundSleep disturbance is common in individuals with psoriasis and appears to be related to both physical and psychological factors. We sought to examine whether psoriasis symptoms, night-time arousal and low mood predicted subsequent objective and self-reported sleep; and whether objective and self-reported sleep predicted next-day psoriasis symptoms and day-time functioning.Participants/MethodsA total of 19 individuals (Female: 11 [57.9%], median age: 39 years) with chronic plaque psoriasis and poor sleep quality (mean Pittsburgh Sleep Quality Index, PSQI = 9.11) participated. Momentary assessments of psoriasis symptoms, mood and daytime functioning were completed at five pseudo-random intervals each day for 15 days using time-stamped digital diary entry. Objective sleep was estimated using wrist-worn actigraphy. Self-reported sleep and night-time arousal were assessed each morning using validated measures.Results and conclusionsTwo-level random intercept models showed that increased night-time arousal was associated with poorer diary-reported sleep. Neither self-reported nor objective sleep parameters were associated with daytime psoriasis symptoms in bi-directional analyses. Diary-reported sleep predicted next-day functioning, specifically sleepiness, concentration, and fatigue. Actigraphy-defined total sleep time predicted next-day fatigue. Night-time arousal is associated with poorer self-reported sleep in people with psoriasis, and sleep predicts next-day functioning. Contrary to our hypothesis, sleep disturbance does not appear to be associated with momentary assessments of psoriasis symptoms.     

Disturbed sleep is associated with increased C-reactive protein in young women

Evidence links disturbed sleep with an exaggerated inflammatory response and increased risk of adverse health outcomes. An emerging risk factor for many adverse health outcomes is chronic, low-grade inflammation. An exaggerated inflammatory response could provide a biological link between disturbed sleep and adverse health outcomes. The relationship between sleep and chronic, low-grade inflammation has been sparsely examined in otherwise healthy, young women. We evaluated cross-sectional relationships between self-reported sleep and three inflammatory markers. Participants were community dwelling nonpregnant women (N = 43, 28.2 ± 5.2 years of age). Measures included the Pittsburgh Sleep Quality Index (PSQI), sleep diaries, and serum levels of IL-6, TNF-α and C-reactive protein. Poor sleep quality and continuity were associated with higher CRP levels after controlling for covariates. No significant relationships were observed between PSQI scores and IL-6 or TNF-α; sleep duration was not related to any of the inflammatory markers. Poor sleep, in young adulthood, may contribute to the chronic, low-grade inflammation associated with an increased risk for future adverse health outcomes. Future work should longitudinally evaluate how these relationships may affect development of gender-specific diseases in apparently healthy young women.     

Comparing and contrasting therapeutic effects of cognitive-behavior therapy for older adults suffering from insomnia with short and long objective sleep duration

Study objectivesThis study evaluated the efficacy of a brief group-based program of cognitive-behavior therapy for insomnia (CBTi) for older adults suffering from chronic insomnia with short objective sleep relative to those with long sleep duration.MethodNinety-one adults (male = 43, mean age = 63.34, standard deviation (SD) = 6.41) with sleep maintenance insomnia were selected from a community-based sample. The participants were classified as short sleepers (SS; <6 h total sleep time) or long sleepers (LS; ≥6 h total sleep time) based on one night of home-based polysomnography. Participants were randomly allocated to a 4-week, group-based treatment program of CBTi (N = 30 SS; N = 33 LS) or to a wait-list control condition (N = 9 SS, N = 19 LS). One-week sleep diaries, actigraphy, and a comprehensive battery of questionnaires were used to evaluate the efficacy of CBTi for those with short objective sleep relative to those with long sleep duration. Outcome measures were taken at pretreatment, posttreatment, and a 3-month follow-up.ResultsCBTi produced robust and durable improvements in quality of sleep, including reduced wake after sleep onset and improved sleep efficiency. Participants reported a reduction of scores on the Insomnia Severity Index, Flinders Fatigue Scale, Epworth Sleepiness Scale, Daytime Feeling and Functioning Scale, Sleep Anticipatory Anxiety Questionnaire, the Dysfunctional Beliefs and Attitudes about Sleep Scale, and gains on the Sleep Self-Efficacy Scale. All improvements were significant relative to their respective SS or LS wait-list group. The benefits of CBTi were comparable with those who had short and long objective sleep before the treatment.ConclusionsOlder adults suffering from chronic insomnia with short objective sleep received comparable therapeutic benefits following CBTi relative to those with long objective sleep duration.     

Sleep profile in a population of community-dwelling nonagenarians: data from the Mugello study

Background

Very few studies have investigated sleep characteristics in the oldest-old individuals (aged ≥85 years) and data collected often rely on self-reported information. This study had three aims: (i) to objectively assess, using a wearable device, the sleep characteristics of a large community of oldest-old subjects; (ii) to assess differences in sleep parameters between self-reported ‘good sleepers’ and ‘bad sleepers’; (iii) to assess whether there was a relationship between sleep parameters and cognitive status in this community-dwelling population.

Methods

There were 178 subjects (74.2% women, median age 92 years) included in the ‘Mugello study’, who wore an armband 24 h/day for at least two consecutive nights to estimate sleep parameters. The perceived sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI), the cognitive status through the Mini-Mental State Examination. Continuous variables were compared between men/women, and good/bad sleepers with the independent t-test or Mann–Whitney U-test, according to data distribution. Chi-square test was used for categorical/dichotomous variables. An ordinal logistic regression model was used to study the possible association between sleep parameters and cognitive function.

Results

Participants spent in bed nearly 9 h, with a total sleep time of 7 h, a sleep onset latency of 17 min, and a sleep efficiency of 83%. Sleep onset latency was significantly associated with different cognitive levels when age and education level were considered. No significant difference in sleep parameters estimated using the SenseWear armband were found between poor (n = 136, 76.4%) and good sleepers (n = 42, 23.6%), identified according to the PSQI.

Conclusions

In this study, actigraphic measurements revealed that subjects with a cognitive decline were more prone to increased sleep onset latency. Sleep quality assessed using the PSQI was not coherent with actigraphic measurements in this sample, supporting the need for objective measures when investigating sleep quality in the oldest-old population.     

Self-reported sleep quality and dysfunctional sleep-related beliefs in young and older adults: changes in times of COVID-19 lockdown

ObjectiveThis study examined changes due to COVID-19 lockdown in young and older adults’ self-reported sleep quality and dysfunctional sleep-related beliefs.MethodsAdults involved in studies prior to the pandemic were contacted during the COVID-19 lockdown. Seventeen young adults (age range: 18–35 years) and 21 older adults (age range: 65–90 years) agreed to participate. Participants were interviewed by phone (between 27th April and 4^th May, 2020) to complete the Pittsburgh Sleep Quality Index (PSQI) and the Dysfunctional Beliefs About Sleep (DBAS) questionnaire they had been administered before the pandemic.ResultsIn terms of mean changes, the results showed null effect sizes for changes in self-reported sleep quality for both age groups. In young adults, a medium effect size emerged for changes in sleep latency, which increased during lockdown. No changes in any of the self-reported sleep quality dimensions emerged in older adults. In both age groups, the effect sizes for changes in dysfunctional sleep-related beliefs were negligible. In older adults, however, changes in self-reported sleep quality were largely associated with changes in dysfunctional sleep-related beliefs.ConclusionsOur results suggest that self-reported sleep quality and dysfunctional sleep-related beliefs were not affected by the COVID-19 lockdown in young or older adults. They also suggest that it might be useful to consider changes in dysfunctional sleep-related beliefs to better capture the impact of stressful events (such as a period of quarantine) on sleep quality, especially where older adults are concerned.     

Subjective versus objective sleep outcomes in older adults with and without uncoupled sleep following online cognitive behavioural therapy for insomnia

Background

Uncoupled sleep is a phenomenon characterised by a disconnect between sleep pattern and sleep complaint. This study examined the impact of uncoupled sleep on dysfunctional sleep beliefs and objective and subjective sleep outcomes in community-dwelling older adults following digitally delivered Cognitive Behavioural Therapy for Insomnia (CBT-I) to assess how these groups respond to CBT-I.

Methods

Objective sleep was measured using wrist actigraphy, subjective sleep quality via sleep diaries and the Pittsburgh Sleep Quality Index (PSQI). Dysfunctional sleep beliefs were assessed by the Dysfunctional Beliefs and Attitudes about Sleep scale (DBAS-16). All measurements were taken prior to and following a 4-week online CBT-I program. Linear mixed model and generalised linear mixed model analyses were conducted to examine objective and subjective sleep onset latency, total sleep time, wake after sleep onset and number of awakenings as well as PSQI and DBAS-16 scores, respectively.

Results

Out of 80 enrolled participants, 62 participants (55 females, 89%; 16 complaining good sleepers, 26 complaining poor sleepers, 11 non-complaining good sleepers, and nine non-complaining poor sleepers) completed the study. CBT-I reduced dysfunctional sleep beliefs across all sleeper classifications. Objective and self-reported changes in sleep parameters were demonstrated in complaining poor sleepers without uncoupled sleep. Complaining good sleepers with uncoupled sleep only reported a decrease in the number of subjective sleep awakenings. There were no changes in sleep outcomes in non-complaining good and non-complaining poor sleepers.

Conclusions

Online CBT-I was effective in improving the sleep outcomes of individuals who had both subjective and objective poor sleep. However, as the online CBT-I reduced dysfunctional sleep beliefs in all sleep groups, further examination of dysfunctional sleep beliefs and whether they mediate the outcomes of digital CBT-I in older adults will need to be conducted.     

Bidirectional,Temporal Associations of Sleep with Positive Events,Affect, and Stressors in Daily Life Across a Week

Background

Sleep is intricately tied to emotional well-being, yet little is known about the reciprocal links between sleep and psychosocial experiences in the context of daily life.

Purpose

The aim of this study is to evaluate daily psychosocial experiences (positive and negative affect, positive events, and stressors) as predictors of same-night sleep quality and duration, in addition to the reversed associations of nightly sleep predicting next-day experiences.

Methods

Daily experiences and self-reported sleep were assessed via telephone interviews for eight consecutive evenings in two replicate samples of US employees (131 higher-income professionals and 181 lower-income hourly workers). Multilevel models evaluated within-person associations of daily experiences with sleep quality and duration. Analyses controlled for demographics, insomnia symptoms, the previous day’s experiences and sleep measures, and additional day-level covariates.

Results

Daily positive experiences were associated with improved as well as disrupted subsequent sleep. Specifically, positive events at home predicted better sleep quality in both samples, whereas greater positive affect was associated with shorter sleep duration among the higher-income professionals. Negative affect and stressors were unrelated to subsequent sleep. Results for the reversed direction revealed that better sleep quality (and, to a lesser degree, longer sleep duration) predicted emotional well-being and lower odds of encountering stressors on the following day.

Conclusions

Given the reciprocal relationships between sleep and daily experiences, efforts to improve well-being in daily life should reflect the importance of sleep.

     

Increases in duration of first uninterrupted sleep period are associated with improvements in PSQI-measured sleep quality

Objective

Urology clinical trials assessing bladder function have relied on the self-reported duration of the first uninterrupted sleep period (FUSP) as a proxy outcome for sleep, but the relationship between this measure and more conventional self-reported measures of sleep is unknown. In this study, we examined the association between changes in FUSP and a widely used self-reported measure of sleep, the Pittsburgh Sleep Quality Index (PSQI).

Methods

We conducted post hoc (secondary) analyses of unpublished data from a previously published randomized clinical trial (NCT00477490) of desmopressin (a medication used to treat nocturia) and examined relationships between baseline and 4-week change in FUSP and PSQI global and subscale scores for participants (N = 580 to N = 606) having complete data.

Results

Data indicated strong associations between change in PSQI global score and FUSP change in six of seven subscale scores. A reduction of 1.8 points in the PSQI global score was associated with a 72-min lengthening of FUSP.

Conclusions

Results suggest that FUSP is a potentially valuable metric that correlates with changes in perceived sleep duration, depth, quality for the entire night, efficiency, latency, and daytime function. An increase in FUSP was related to improvement in nearly all PSQI subscales. The validity of this measure in the general population remains to be determined.     

Positive affect, psychological well-being, and good sleep

OBJECTIVE: To discover whether positive affect and purpose in life (eudaimonic well-being) are associated with good sleep independently of health problems and socioeconomic status, and to evaluate their role in mediating the influence of psychosocial risk factors on poor sleep. METHODS: A cross-sectional study was carried out with 736 men and women aged 58-72 years, with positive affect assessed by aggregating ecological momentary samples. Sleep problems were assessed with the Jenkins Sleep Problems Scale, and psychosocial risk factors were measured by standardized questionnaires. RESULTS: Both positive affect and eudaimonic well-being were inversely associated with sleep problems after adjustment for age, gender, household income, and self-rated health (P<.001). Negative psychosocial factors including financial strain, social isolation, low emotional support, negative social interactions, and psychological distress were also related to reported sleep problems. The strength of these associations was reduced by 20-73% when positive affect and eudaimonic well-being were taken into account, suggesting that effects were partly mediated by positive psychological states. CONCLUSIONS: These results suggest that both positive affect and eudaimonic well-being are directly associated with good sleep and may buffer the impact of psychosocial risk factors. The relationships are likely to be bidirectional, with disturbed sleep engendering lower positive affect and reduced psychological well-being, and positive psychological states promoting better sleep.     

Sleep disturbance mediates the association between psychological distress and immune status among HIV-positive men and women on combination antiretroviral therapy

OBJECTIVES: This study examined the relationship between psychological distress, subjective sleep disturbance and immune status among HIV-positive men and women. METHODS: Fifty-seven participants (41 men, 16 women) without AIDS-related illness and currently on combination antiretroviral therapy were recruited through community advertisement and physician referral. Participants completed the Impact of Events Scale (IES) to assess symptoms of psychological distress and the Pittsburgh Sleep Quality Index (PSQI) to assess quality of sleep over the past month. T-lymphocyte subpopulations were also assessed from early morning blood samples. RESULTS: Participants reporting greater psychological distress also reported more pronounced sleep disruption. Higher levels of distress and greater sleep disturbance were also significantly related to lower T-cytotoxic/suppressor (CD3+CD8+) cell counts. Path analysis revealed that the association between distress level and CD3+CD8+ cell counts was mediated by poorer subjective sleep quality. CONCLUSIONS: These findings suggest that psychological distress may impact upon the immune system through its effects on sleep quality.     

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.     

Disparities in sleep characteristics by race/ethnicity in a population-based sample: Chicago Area Sleep Study

BackgroundPrior studies report less favorable sleep characteristics among non-Whites as compared with non-Hispanic Whites. However, few population-based studies have used objective measures of sleep duration, especially in more than two racial/ethnic groups. We tested whether objectively estimated sleep duration and self-reported sleep quality varied by race and whether differences were at least partially explained by the variability in clinical, psychological, and behavioral covariates.MethodsAdults aged 35–64 years who self-identified as White, Black, Asian, or Hispanic were randomly sampled from Chicago, IL, and the surrounding suburbs. Our analytic sample included adults who had an apnea–hypopnea index <15 after one night of screening and who completed seven nights of wrist actigraphy for determination of sleep duration, sleep percentage, minutes of wake after sleep onset, and sleep fragmentation (n = 495). Daytime sleepiness was estimated using the Epworth Sleepiness Scale (ESS), and sleep quality was estimated from the Pittsburgh Sleep Quality Index (PSQI).ResultsFollowing statistical adjustment for age, gender, education, work schedule (ie, day vs. night shift), smoking status, depressive symptoms, body mass index (BMI), hypertension, and diabetes, sleep duration (minutes) was significantly (all p < 0.01) shorter in Black (mean = 399.5), Hispanic (mean = 411.7), and Asian (mean = 409.6) participants than in White participants (mean = 447.4). All remaining sleep characteristics were significantly less favorable among Black participants as compared with White participants. Asian participants also reported significantly more daytime sleepiness than did White participants.ConclusionsDifferences in sleep characteristics by race/ethnicity are apparent in a sample of adults with a low probability of sleep apnea and following adjustment for known confounders.     

What keeps low-SES children from sleeping well: the role of presleep worries and sleep environment

ObjectivesChildren in families of low socioeconomic status (SES) have been found to have poor sleep, yet the reasons for this finding are unclear. Two possible mediators, presleep worries and home environment conditions, were investigated as indirect pathways between SES and children's sleep.Participants/MethodsThe participants consisted of 271 children (M (age) = 11.33 years; standard deviation (SD) = 7.74 months) from families varying in SES as indexed by the income-to-needs ratio. Sleep was assessed with actigraphy (sleep minutes, night waking duration, and variability in sleep schedule) and child self-reported sleep/wake problems (eg, oversleeping and trouble falling asleep) and sleepiness (eg, sleeping in class and falling asleep while doing homework). Presleep worries and home environment conditions were assessed with questionnaires.ResultsLower SES was associated with more subjective sleep/wake problems and daytime sleepiness, and increased exposure to disruptive sleep conditions and greater presleep worries were mediators of these associations. In addition, environmental conditions served as an intervening variable linking SES to variability in an actigraphy-derived sleep schedule, and, similarly, presleep worry was an intervening variable linking SES to actigraphy-based night waking duration. Across sleep parameters, the model explained 5–29% of variance.ConclusionsSleep environment and psychological factors are associated with socioeconomic disparities, which affect children's sleep.     

Association between sleep quality and subjective cognitive decline: evidence from a community health survey

ObjectivesLittle is known concerning whether subjective cognitive decline (SCD) is associated with sleep quality. This study aimed to identify the association between self-reported quality of sleep and SCD in a large population of middle-aged and older adults in Korea.MethodsWe conducted this study based on data collected from the 2018 Korean Community Health Survey. Individuals aged 40 years and older who responded to the Behavioral Risk Factor Surveillance System (BRFSS) and Pittsburgh Sleep Quality Index (PSQI) assessments and did not lack data about multiple covariates were included. A total of 37,712 respondents with SCD and 135,119 those without SCD were included. Sleep quality was estimated using the PSQI, which includes seven self-reported components for sleep health assessment. SCD was assessed using the BRFSS. Logistic regression models adjusted for confounders were used to examine whether each component of the sleep quality index was related to SCD. Additional analysis of the correlation between quantified scores for each component and SCD-related functional limitations as ordinal variables was performed.ResultsThe mean age was 62.7 years in the SCD group and 56.4 years in the control group. In total, 13,777 (28.9%) respondents were male in the SCD group and 62,439 (50.7%) in the control group. The adjusted odds ratios of SCD were 1.25 for very bad sleep quality, 1.26 for long sleep latency, 1.16 for <5 h of sleep duration, 1.08 for <65% habitual sleep efficiency, 2.29 for high sleep disturbance, 1.26 for use of sleep medication ≥3 times a week, and 2.47 for high daytime dysfunction due to sleep problems compared to good sleep conditions. Furthermore, a higher score for each component of the sleep quality index correlated with greater SCD-related functional limitations.ConclusionsOur study provides evidence that poor sleep quality is closely related to both SCD and SCD-related functional limitations.     

Sleep and sadness: exploring the relation among sleep,cognitive control,and depressive symptoms in young adults

BackgroundSleep disturbance is a common feature of depression. However, recent work has found that individuals who are vulnerable to depression report poorer sleep quality compared to their low-risk counterparts, suggesting that sleep disturbance may precede depression. In addition, both sleep disturbance and depression are related to deficits in cognitive control processes. Thus we examined if poor sleep quality predicts subsequent increases in depressive symptoms and if levels of cognitive control mediated this relation.MethodsThirty-five undergraduate students participated in two experimental sessions separated by 3 weeks. Participants wore an actigraph watch between sessions, which provided an objective measure of sleep patterns. We assessed self-reported sleep quality and depressive symptoms at both sessions. Last, individuals completed an exogenous cuing task, which measured ability to disengage attention from neutral and negative stimuli during the second session.ResultsUsing path analyses, we found that both greater self-reported sleep difficulty and more objective sleep stability measures significantly predicted greater difficulty disengaging attention (i.e., less cognitive control) from negative stimuli. Less cognitive control over negative stimuli in turn predicted increased depression symptoms at the second session. Exploratory associations among the circadian locomotor output cycles kaput gene, CLOCK, single nucleotide polymorphism (SNP), rs11932595, as well as sleep assessments and depressive symptoms also are presented.ConclusionsThese preliminary results suggest that sleep disruptions may contribute to increases in depressive symptoms via their impact on cognitive control. Further, variation in the CLOCK gene may be associated with sleep quality.     

Interpersonal distress is associated with sleep and arousal in insomnia and good sleepers

Objective

The interpersonal environment is strongly linked to sleep. However, little is known about interpersonal distress and its association with sleep. We examined the associations among interpersonal distress, objective and subjective sleep in people with and without insomnia.

Methods

Participants in this cross-sectional observational study included men and women with insomnia (n = 28) and good sleeper controls (n = 38). Interpersonal distress was measured with the Inventory of Interpersonal Problems. Sleep parameters included insomnia severity, self-reported presleep arousal, and sleep quality; and polysomnographically-assessed sleep latency (SL), total sleep time (TST), wake after sleep onset (WASO), percent delta (stage 3 + 4 NREM), percent REM, and EEG beta power. Hierarchical linear regression was used to assess the relationship between distress from interpersonal problems and sleep and the extent to which relationships differed among insomnia patients and controls.

Results

More interpersonal distress was associated with more self-reported arousal and higher percentage of REM. More interpersonal distress was associated with greater insomnia severity and more cognitive presleep arousal for individuals with insomnia, but not for controls. Contrary to expectations, interpersonal distress was associated with shorter sleep latency in the insomnia group. Results were attenuated, but still significant, after adjusting for depression symptoms.

Conclusion

Distress from interpersonal problems is associated with greater self-reported arousal and higher percent REM. Individuals with insomnia who report more distress from interpersonal problems have greater insomnia severity and cognitive presleep arousal, perhaps due to rumination. These findings extend our knowledge of the association between interpersonal stressors and sleep. Assessment and consideration of interpersonal distress could provide a novel target for insomnia treatment.     

Subjective and objective sleep indices in women with irritable bowel syndrome

Patients with irritable bowel syndrome (IBS) commonly report sleep disturbances. This study examined self-report (Pittsburgh Sleep Quality Inventory) sleep quality and polysomnography (PSG) sleep variables in 18 women with mild-to-moderate IBS, 18 with severe IBS and 38 with age- and gender-matched controls. All women were studied on two consecutive nights in a sleep research laboratory where PSG data were collected. Retrospective and daily measures were obtained of self-reported sleep quality, psychological distress and gastrointestinal symptoms across one menstrual cycle. Self-report measures of psychological distress and sleep quality were significantly worse in the IBS-severe (IBS-S) group compared with controls. Rapid eye movement (REM) latency was higher in the two IBS groups on Night 1 than the control group (P = 0.06). Percentage time in REM was highest in the IBS-S on Night 2. All groups demonstrated greater sleep disruption on Night 1 (adaptation) when compared with Night 2. These results highlight the importance of considering the 'first-night effect' in those with IBS and the lack of concordance between self-report and objective indices of sleep in women with IBS.