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

Sleep During the COVID-19 Pandemic: Longitudinal Observational Study Combining Multisensor Data With Questionnaires

BACKGROUND

The COVID-19 pandemic prompted various containment strategies, such as work-from-home policies and reduced social contact, which significantly altered people's sleep routines. While previous studies have highlighted the negative impacts of these restrictions on sleep, they often lack a comprehensive perspective that considers other factors, such as seasonal variations and physical activity (PA), which can also influence sleep.

OBJECTIVE

This study aims to longitudinally examine the detailed changes in sleep patterns among working adults during the COVID-19 pandemic using a combination of repeated questionnaires and high-resolution passive measurements from wearable sensors. We investigate the association between sleep and 5 sets of variables: (1) demographics; (2) sleep-related habits; (3) PA behaviors; and external factors, including (4) pandemic-specific constraints and (5) seasonal variations during the study period.

METHODS

We recruited working adults in Finland for a 1-year study (June 2021-June 2022) conducted during the late stage of the COVID-19 pandemic. We collected multisensor data from fitness trackers worn by participants, as well as work and sleep-related measures through monthly questionnaires. Additionally, we used the Stringency Index for Finland at various points in time to estimate the degree of pandemic-related lockdown restrictions during the study period. We applied linear mixed models to examine changes in sleep patterns during this late stage of the pandemic and their association with the 5 sets of variables.

RESULTS

The sleep patterns of 27,350 nights from 112 working adults were analyzed. Stricter pandemic measures were associated with an increase in total sleep time (TST) (β=.003, 95% CI 0.001-0.005; P<.001) and a delay in midsleep (MS) (β=.02, 95% CI 0.02-0.03; P<.001). Individuals who tend to snooze exhibited greater variability in both TST (β=.15, 95% CI 0.05-0.27; P=.006) and MS (β=.17, 95% CI 0.03-0.31; P=.01). Occupational differences in sleep pattern were observed, with service staff experiencing longer TST (β=.37, 95% CI 0.14-0.61; P=.004) and lower variability in TST (β=-.15, 95% CI -0.27 to -0.05; P<.001). Engaging in PA later in the day was associated with longer TST (β=.03, 95% CI 0.02-0.04; P<.001) and less variability in TST (β=-.01, 95% CI -0.02 to 0.00; P=.02). Higher intradaily variability in rest activity rhythm was associated with shorter TST (β=-.26, 95% CI -0.29 to -0.23; P<.001), earlier MS (β=-.29, 95% CI -0.33 to -0.26; P<.001), and reduced variability in TST (β=-.16, 95% CI -0.23 to -0.09; P<.001).

CONCLUSIONS

Our study provided a comprehensive view of the factors affecting sleep patterns during the late stage of the pandemic. As we navigate the future of work after the pandemic, understanding how work arrangements, lifestyle choices, and sleep quality interact will be crucial for optimizing well-being and performance in the workforce.

Irregular sleep is linked to poorer mental health: A pooled analysis of eight studies

OBJECTIVES

Greater sleep disturbances on average are a risk factor for impaired mental health. Recent research has shown that more intraindividual variability (i.e., inconsistency) in sleep (hereafter called "sleep intraindividual variability") may also be uniquely related to mental health, even above the influence of mean sleep patterns averaged across days. The current study examined associations between sleep intraindividual variability and symptoms of anxiety, depression, and insomnia across different facets of sleep intraindividual variability (sleep duration, efficiency, and timing) and sleep measurement types (sleep diary and actigraphy).

METHODS

We pooled eight datasets (N = 3053 participants) that assessed repeated measures of sleep diary- and/or actigraphy-determined sleep across multiple days, as well as one-time measures of mental health or sleep disorder symptoms (i.e., anxiety, depression, and insomnia). Multilevel regression analyses were conducted to examine associations between sleep intraindividual variability and mental health or sleep disorder symptoms.

RESULTS

Greater diary- and actigraphy-determined sleep duration intraindividual variability was associated with more depression symptoms (diary: b=0.02, p < .001; actigraphy: b=0.03, p = .006) and more insomnia symptoms (diary: b=0.02, p < .001; actigraphy: b=0.02, p < .001). Greater diary-determined sleep efficiency intraindividual variability was associated with fewer anxiety symptoms (b=-0.23, p = .019) and fewer insomnia symptoms (b=-0.15, p < .001). Greater diary- and actigraphy-determined sleep midpoint intraindividual variability was associated with more insomnia symptoms (diary: b=0.41, p = .044; actigraphy: b=0.66, p = .021).

CONCLUSIONS

More inconsistent sleep duration and sleep timing may be a correlate of poorer mental health. Future experimental work should examine whether stabilizing sleep patterns can improve mental health outcomes.

Negative attention bias and attentional control as mechanisms in the association between insomnia and depression in young people

Evidence supports a causal role of insomnia in the development and maintenance of depression, yet mechanisms underlying this association in young people are not well established. Attention biases have been implicated separately in the sleep and depression fields and represents an important candidate mechanism. Poor sleep may lead to a negative attention bias (characteristic of depression) by impacting attentional control. This study assessed the hypothesis that attentional control and negative attention bias would sequentially mediate the relationship between insomnia and depressive symptoms in an unselected sample of young people (17-24 years). Concerns have been raised regarding the psychometric properties of tasks used to measure attention bias, and a Dual-Probe Task is emerging as a more reliable measure. Participants (N = 275, Male = 59, Mage = 19.40) completed the Dual-Probe Task, a behavioural measure of attentional control, and self-report measures of insomnia and depression. Participants completed a one-week sleep diary. Results were consistent with negative attention bias, but not attentional control, as a mechanism which partially accounts for the relationship between sleep (i.e., insomnia severity, sleep duration, sleep efficiency, sleep latency) and depression. This study highlights sleep and negative attention bias as potentially modifiable risk factors to reduce depressive symptoms in young people.

Familial risk for depression is associated with reduced physical activity in young adults: evidence from a wrist-worn actigraphy study

Depression is characterized by reduced physical activity and sleep-wake cycle disturbances, often considered important features of the disease. While a few studies have suggested that self-reported reduced physical activity and sleep-wake cycle disturbances might both be linked to depression vulnerability, actigraphy-based measures in vulnerable samples remain largely unexplored. This study relied on actigraphy-based parameters to test whether these disturbances characterize depression vulnerability. Seven-day actigraphy data were collected from 20 (13 female) university students with a high vulnerability to depression, which was determined by the presence of a family history of the condition but no current symptoms, and 32 (21 female) controls with neither a family history of depression nor current depressive symptoms. Daily physical activity, namely gross motor activity, was quantified as average daily acceleration and time spent engaging in moderate-vigorous physical activity (MVPA). The sleep-wake cycle and circadian rhythms were assessed as total sleep duration per night (in hours), sleep within sleep period time (in hours), sleep efficiency (%), and relative amplitude (i.e., the difference between the activity during the day and the night, which reflects circadian rhythms amplitude). Results showed that individuals with a familial risk for depression exhibited reduced daily acceleration and time spent in MVPA relative to the control group, particularly on the weekend during their free time away from scheduled activities. On the other hand, the two groups were comparable in terms of sleep estimates. Taken together, reduced physical activity, but not sleep-wake disturbances, seem to be associated with vulnerability to depression and might be a viable target for identification and prevention efforts.

Prevalence of Sleep Disturbance Potential-Associated Factors among Undergraduate Pharmacy Students in Saudi Arabia

Background

Many studies across the globe have observed the significant effect of sleep disturbance on the academic achievement of medical students. Objective: This research was conducted to define the prevalence of sleep disturbance and to discover the consequences and management of this condition among undergraduate pharmacy students of Mohammed Al-Mana College for Medical Sciences (MACHS).

Methods

We conducted a questionnaire-based online survey among different levels of MACHS pharmacy students.

Results

A total of 165 students participated in the study, of whom 132 (80%) were females and 33 (20%) were males. Most of the participants, 142 (86.06%), were staying with their parents, whereas few of them were staying alone (23; 13.94%). While a handful of them, 29 (17.58%), did not have their bedrooms, most of them had their bedrooms (136; 82.42%). When asked about drinking caffeine-rich products in the afternoon or at night, most of them responded "sometimes" (78; 47.27%), followed by the category "always" (61; 36.97%), "rarely" (15; 9.09%), and then the category of students who responded "not at all" (11; 6.67%). Overall, 35 (21.21%) of the study participants had a smoking habit, 72 (43.63%) tried to treat their sleep disturbance, whereas 42 (25.45%) were getting treatment for insomnia.

Conclusion

Most pharmacy students at MACH College, especially females, have sleep problems. Mostly, the prevalence is common during exam periods, and it mildly affects their grade point average.

An Examination of Sleep as a Mediator of the Relationship between Childhood Adversity and Depression in Hispanic and Non-Hispanic Young Adults

The current study integrates previous research on adverse childhood experiences (ACEs) and long-term health outcomes to examine associations between ACEs, sleep duration, and depression in a diverse, mostly healthy, sample of young adults. We examine whether sleep duration mediates the association between ACEs and depression among young adults, and whether ethnicity may moderate observed relationships between ACEs, sleep duration and depression. Data were collected from 518 young adults (66.8% female, Mage=19.79 years, SDage=3.43 years) enrolled in undergraduate Psychology courses at a large Southwestern university. Participants primarily reported their racial/ethnic background as Non-Hispanic White (60.6%) and Hispanic/Latino (25.1%). Participants self-reported their ACEs exposure, sleep characteristics, and depressive symptoms. In addition to calculating overall exposure to ACEs, scores for the specific dimensions of adversity were also calculated (Abuse, Neglect, Exposure to Violence). Results supported a mediation model whereby higher reports of ACEs were associated with depressive symptoms both directly and through sleep duration. Results were not moderated by ethnicity. Findings provide support for sleep duration as one potential pathway through which ACEs may be associated with depressive symptoms in young adulthood, and suggest that this pathway is similar in Hispanic and non-Hispanic young adults.

Assessing 'readiness' by tracking fluctuations in daily sleep duration and their effects on daily mood, motivation, and sleepiness

STUDY OBJECTIVES

Consumer sleep trackers issue daily guidance on 'readiness' without clear empirical basis. We investigated how self-rated mood, motivation, and sleepiness (MMS) levels are affected by daily fluctuations in sleep duration, timing, and efficiency and overall sleep regularity. We also determined how temporally specific these associations are.

METHODS

119 healthy university students (64 female, mean age = 22.54 ± 1.74 years) wore a wearable sleep tracker and undertook twice-daily smartphone-delivered ecological momentary assessment of mood, motivation, and sleepiness at post-wake and pre-bedtime timings for 2-6 weeks. Naps and their duration were reported daily. Nocturnal sleep on 2471 nights were examined using multilevel models to uncover within-subject and between-subject associations between sleep duration, timing, efficiency, and nap duration on following day MMS ratings. Time-lagged analyses examined the temporal specificity of these associations. Linear regression models investigated associations between MMS ratings and sleep variability, controlling for sleep duration.

RESULTS

Nocturnal sleep durations were short (6.03 ± 0.71 h), and bedtimes were late (1:42AM ± 1:05). Within-subjects, nocturnal sleep longer than a person's average was associated with better mood, higher motivation, and lower sleepiness after waking. Effects of such longer sleep duration lingered for mood and sleepiness till the pre-bedtime window (all Ps < .005) but did not extend to the next day. Between-subjects, higher intraindividual sleep variability, but not sleep duration, was associated with poorer mood and lower motivation after waking. Longer average sleep duration was associated with less sleepiness after waking and lower motivation pre-bedtime (all Ps < .05). Longer naps reduced post-nap sleepiness and improved mood. Controlling for nocturnal sleep duration, longer naps also associated with lower post-waking sleepiness on the following day.

CONCLUSIONS

Positive connections between nocturnal sleep and nap duration with MMS are temporally circumscribed, lending credence to the construction of sleep-based, daily 'readiness' scores. Higher sleep duration variability lowers an individual's post waking mood and motivation.

CLINICAL TRIAL ID

ClinicalTrials.gov NCT04880629.

Longitudinal assessment of the sleep suicide link in Veterans: methods and study protocol

Although sleep disruption has emerged as a theoretically consistent and empirically supported suicide risk factor, the mechanistic pathways underlying the sleep-suicide link are less understood. This paper describes the methodology of a study intended to examine longitudinal mechanisms driving the link between sleep and suicide in Veterans at elevated suicide risk. Participants will be 140 Veterans hospitalized for suicide attempt or ideation with plan and intent or those identified through the Suicide Prevention Coordinator (SPC) office as being at acute risk. After study enrollment, actigraphy and ecological momentary assessment (EMA) data will be collected for 8 weeks, with follow-up assessments occurring at 2, 4, 6, 8, and 26 weeks. Participants respond to EMA questionnaires, derived from psychometrically validated assessments targeting emotional reactivity, emotion regulation, impulsivity, suicide risk, and sleep timing constructs, five times a day. First and last daily EMA target sleep parameters including sleep quantity, quality, timing, nightmares, and nocturnal awakenings. During follow-up assessments, participants will complete self-report assessments and interviews consistent with EMA constructs and the Iowa Gambling Task. The primary outcome for aim 1 is suicide ideation severity and for the primary outcome for aim 2 is suicide behavior. Findings from this study will improve our understanding of the dynamic interactions among sleep disturbance, emotion reactivity/regulation, and impulsivity to inform conceptual Veteran sleep-suicide mechanistic models. Improved models will be critical to optimizing the precision of suicide prevention efforts that aim to intervene and mitigate risk in Veteran populations, especially during a period of acute risk.

Association of Academic Stress, Acne Symptoms and Other Physical Symptoms in Medical Students of King Khalid University

Academic stress has varied effects on medical student life due to multiple factors, like study load, competition, frequent assessment, social pressure, etc. The authors of this paper conducted research to find the academic stress level and its sequel over acne and other physical symptoms on the medical students of King Khalid University (KKU), Saudi Arabia. A total of 168 participant responses were analyzed. Data collection was performed using a self-administered online questionnaire through the university website portal. The study tool was comprised of four sections: demographic characteristics, academic stress, acne symptoms, and other physical symptoms. Statistical analysis was performed using SPSS software. A high proportion of females (88.7%) participated in the study. Upon categorization of overall academic stress, it was found that a majority of the medical students were moderately stressed (58.34%). The response on the academic stress scale revealed that exams are the major cause of stress among students. The Mean ± SD of academic stress, acne symptoms, and physical symptoms differ significantly at <0.01 level of significance. Overall academic stress showed a significant positive association with acne (<0.01) and physical symptoms (<0.01). The strength of this study is the fact that its categorization of stress caused by academics has not been done elsewhere. In addition, the impact of acne and physical symptoms has not been found in recent literature. Keeping the outcome of the present study in mind, it is suggested to arrange timely counselling sessions in medical colleges which can alert medical students to remain conscious about the consequences of stress.

Dynamic Regulatory Processes in the Transition from Suicidal Ideation to Action in Adults Leaving Inpatient Psychiatric Care: An Intensive Longitudinal Study Protocol (Preprint)

Background

US suicide rates have risen steadily in the past decade, and suicide risk is especially high in the months after discharge from inpatient psychiatric treatment. However, suicide research has lagged in examining dynamic within-person processes that contribute to risk over time among individuals known to be at high risk of suicide. Almost no research has examined how affective, cognitive, and physiological processes change over minutes, hours, or days to confer risk of suicidal behavior in daily life.

Objective

This protocol describes a longitudinal study designed to examine real-world changes in risk of suicide across multiple assessment domains. Specifically, the study involves following adults known to be at high risk of suicide after discharge from inpatient psychiatric care using self-report, interview, actigraphy, and behavioral methods to identify proximal contributors to suicidal thoughts and behaviors. First, we hypothesize that negative affective experiences, which are featured in most major suicide theories, will comprise a latent factor indicative of psychache (emotional pain), which will predict increases in suicidal thinking over time. Second, we hypothesize that poor inhibitory control in the context of negative affective stimuli, as well as emotion-related impulsivity, will predict the transition from suicidal thinking to suicidal behavior over time. Third, we hypothesize that short sleep duration will precede within-person increases in suicidal ideation as well as increased odds of suicidal behavior among those reporting suicidal thoughts.

Methods

The desired sample size is 130 adults with past-week suicidal thoughts or behaviors who are receiving inpatient psychiatric treatment. Participants will complete a battery of measures while on the inpatient unit to assess negative affective experiences, emotion-related impulsivity, inhibitory control, typical sleep patterns, and relevant covariates. After discharge from inpatient care, participants will complete 4 weeks of signal-contingent ecological momentary assessment surveys, as well as mobile behavioral measures of inhibitory control, while wearing an actigraphy device that will gather objective data on sleep. Participants will complete interviews regarding suicidal thoughts and behaviors at 4 and 8 weeks after discharge.

Results

The study was funded by the National Institutes of Health in November 2020. Recruitment began in April 2021. Data analysis will begin after completion of data collection.

Conclusions

This study will elucidate how affective, cognitive, and physiological risk factors contribute (or do not contribute) to within-person fluctuations in suicide risk in daily life, with important implications for extant theories of suicide. Of import, the examined risk factors are all modifiable; thus, the results will inform identification of key targets for just-in-time, flexible, personalized, digital interventions that can be used to decrease emotional distress and prevent suicide among those at highest risk.

International Registered Report Identifier (IRRID)

DERR1-10.2196/38582

Science Forum: Sex differences and sex bias in human circadian and sleep physiology research

Growing evidence shows that sex differences impact many facets of human biology. Here we review and discuss the impact of sex on human circadian and sleep physiology, and we uncover a data gap in the field investigating the non-visual effects of light in humans. A virtual workshop on the biomedical implications of sex differences in sleep and circadian physiology then led to the following imperatives for future research: (1) design research to be inclusive and accessible, (2) implement recruitment strategies that lead to a sex-balanced sample, (3) use data visualization to grasp the effect of sex, (4) implement statistical analyses that include sex as a factor and/or perform group analyses by sex, where possible, (5) make participant-level data open and available to facilitate future meta-analytic efforts.

Digital health tools for the passive monitoring of depression: a systematic review of methods

The use of digital tools to measure physiological and behavioural variables of potential relevance to mental health is a growing field sitting at the intersection between computer science, engineering, and clinical science. We summarised the literature on remote measuring technologies, mapping methodological challenges and threats to reproducibility, and identified leading digital signals for depression. Medical and computer science databases were searched between January 2007 and November 2019. Published studies linking depression and objective behavioural data obtained from smartphone and wearable device sensors in adults with unipolar depression and healthy subjects were included. A descriptive approach was taken to synthesise study methodologies. We included 51 studies and found threats to reproducibility and transparency arising from failure to provide comprehensive descriptions of recruitment strategies, sample information, feature construction and the determination and handling of missing data. The literature is characterised by small sample sizes, short follow-up duration and great variability in the quality of reporting, limiting the interpretability of pooled results. Bivariate analyses show consistency in statistically significant associations between depression and digital features from sleep, physical activity, location, and phone use data. Machine learning models found the predictive value of aggregated features. Given the pitfalls in the combined literature, these results should be taken purely as a starting point for hypothesis generation. Since this research is ultimately aimed at informing clinical practice, we recommend improvements in reporting standards including consideration of generalisability and reproducibility, such as wider diversity of samples, thorough reporting methodology and the reporting of potential bias in studies with numerous features.

Evaluation of Sleep Habits, Generalized Anxiety, Perceived Stress, and Research Outputs Among Postgraduate Research Students in Hong Kong During the Coronavirus (COVID-19) Pandemic

Purpose

The current study aimed to evaluate the impact of coronavirus (COVID-19) pandemic on sleep hygiene, anxiety levels, perceived stress, and research output among postgraduate research students in Hong Kong.

Methods

An online survey was developed and distributed to Hong Kong postgraduate research students. The sleep hygiene, anxiety levels, and perceived stress during the outbreak of COVID-19 were assessed. Questions about COVID-19’s impact on research outputs were asked.

Results

A total of 108 (response rate, 72%) full-time postgraduate students (PhD, 64%; M Phil, 8%; and Masters, 28%) participated. Approximately 83% of students reported poor sleep hygiene. Similarly, nearly 76% of students reported mild to severe levels of self-perceived anxiety levels. Most of the respondents (89%) expressed a moderate level of perceived stress. Sleep hygiene scores were moderately associated with anxiety levels (r = 0.384, p < 0.01) and perceived stress scores (r = 0.423, p < 0.01). Perceived stress was strongly correlated with anxiety levels (r = 0.601, p < 0.01). A hierarchical regression analysis revealed a significant association between respondents’ ethnicity (B = −0.923, p = 0.003), past medical history (such as hypertension, diabetes, and musculoskeletal disorders) (B = 1.112, p = 0.005), or poor sleep hygiene (B = 0.259, p = 0.000) and high levels of perceived stress. Additionally, prior medical history (such as hypertension, diabetes, and musculoskeletal disorders) (B = 1.957, p = 0.001) and poor sleep hygiene (B = 0.312, p = 0.000) were found to be strongly related to anxiety levels among postgraduate research students.

Conclusion

This is the first study that highlights poor sleep hygiene, moderate-to-severe levels of anxiety, and perceived stress during the COVID-19 pandemic in postgraduate research students in Hong Kong. These findings will help educators to prepare strategies to alleviate the stress and psychological problems in postgraduate students.

Measuring sleep regularity: theoretical properties and practical usage of existing metrics

STUDY OBJECTIVES

Sleep regularity predicts many health-related outcomes. Currently, however, there is no systematic approach to measuring sleep regularity. Traditionally, metrics have assessed deviations in sleep patterns from an individual's average; these traditional metrics include intra-individual standard deviation (StDev), interdaily stability (IS), and social jet lag (SJL). Two metrics were recently proposed that instead measure variability between consecutive days: composite phase deviation (CPD) and sleep regularity index (SRI). Using large-scale simulations, we investigated the theoretical properties of these five metrics.

METHODS

Multiple sleep-wake patterns were systematically simulated, including variability in daily sleep timing and/or duration. Average estimates and 95% confidence intervals were calculated for six scenarios that affect the measurement of sleep regularity: "scrambling" the order of days; daily vs. weekly variation; naps; awakenings; "all-nighters"; and length of study.

RESULTS

SJL measured weekly but not daily changes. Scrambling did not affect StDev or IS, but did affect CPD and SRI; these metrics, therefore, measure sleep regularity on multi-day and day-to-day timescales, respectively. StDev and CPD did not capture sleep fragmentation. IS and SRI behaved similarly in response to naps and awakenings but differed markedly for all-nighters. StDev and IS required over a week of sleep-wake data for unbiased estimates, whereas CPD and SRI required larger sample sizes to detect group differences.

CONCLUSIONS

Deciding which sleep regularity metric is most appropriate for a given study depends on a combination of the type of data gathered, the study length and sample size, and which aspects of sleep regularity are most pertinent to the research question.

Sleep quality in the chronic stage of concussion is associated with poorer recovery: A systematic review

Background

Recovery from a concussion varies based on a multitude of factors. One such factor is sleep disturbances. In our prior review, it was observed that in the acute phase, sleep disturbances are predictive of poor outcomes following a concussion. The literature gap remains on how sleep in the chronic phase of recovery affects outcomes.

Objective

To examine the association between sleep quality during the chronic stage of concussion and post-concussion outcomes. Literature Survey: Literature searches were performed during 1 July to 1 August 2019 in selected databases along with searching grey literature. Out of the 733 results, 702 references were reviewed after duplicate removal.

Methods

Three reviewers independently reviewed and consented on abstracts meeting eligibility criteria ( n = 35). The full-text articles were assessed independently by two reviewers. Consensus was achieved, leaving four articles. Relevant data from each study was extracted using a standard data-extraction table. Quality appraisal was conducted to assess potential bias and the quality of articles.

Results

One study included children (18–60 months) and three studies included adolescents and/or adults (ranging 12–35 years). The association between sleep and cognition (two studies), physical activity (one study), and emotion symptoms (one study) was examined. Sleep quality was associated with decreased cognition and emotional symptoms, but not with meeting physical activity guidelines six months post-concussion injury.

Conclusions

The heterogeneity in age of participants and outcomes across studies and limited number of included studies made interpretations difficult. Future studies may consider if addressing sleep quality following concussion will improve outcomes.

The effect of sleep-wake intraindividial variability in digital cognitive behaviour therapy for insomnia: A mediation analysis of a large-scale RCT

Study Objectives

Digital cognitive behavioral therapy for insomnia (dCBT-I) is an effective treatment for insomnia. However, less is known about mediators of its benefits. The aim of the present study was to test if intraindividual variability in sleep (IIV) was reduced with dCBT-I, and whether any identified reduction was a mediator of dCBT-I on insomnia severity and psychological distress.

Methods

In a two-arm randomized controlled trial (RCT), 1720 adults with insomnia (dCBT-I = 867; patient education about sleep = 853) completed the Insomnia Severity Index (ISI), the Hospital Anxiety and Depression Scale (HADS) and sleep diaries, at baseline and 9-week follow-up. Changes in IIV were analyzed using linear mixed modeling followed by mediation analyses of ISI, HADS, and IIV in singular sleep metrics and composite measures (behavioral indices (BI-Z) and sleep disturbance indices (SI-Z)).

Results

dCBT-I was associated with reduced IIV across all singular sleep metrics, with the largest between-group effect sizes observed for sleep onset latency (SOL). Reduced IIV for SOL and wake after sleep onset had the overall greatest singular mediating effect. For composite measures, SI-Z mediated change in ISI (b = −0.74; 95% confidence interval (CI) −1.04 to −0.52; 13.3%) and HADS (b = −0.40; 95% CI −0.73 to −0.18; 29.2%), while BI-Z mediated minor changes.

Conclusion

Reductions in IIV in key sleep metrics mediate significant changes in insomnia severity and especially psychological distress when using dCBT-I. These findings offer important evidence regarding the therapeutic action of dCBT-I and may guide the future development of this intervention.

Clinical trials

Name: Overcoming Insomnia: Impact on Sleep, Health and Work of Online CBT-I

Registration number: NCT02558647

URL: https://clinicaltrials.gov/ct2/show/NCT02558647?cond=NCT02558647&draw=2&rank=1

Sleep quality relates to emotional reactivity via intracortical myelination

A good quality and amount of sleep are fundamental to preserve cognition and affect. New evidence also indicates that poor sleep is detrimental to brain myelination. In this study, we test the hypothesis that sleep quality and/or quantity relate to variability in cognitive and emotional function via the mediating effect of interindividual differences in proxy neuroimaging measures of white matter integrity and intracortical myelination. By employing a demographically and neuropsychologically well-characterized sample of healthy people drawn from the Human Connectome Project (n = 974), we found that quality and amount of sleep were only marginally linked to cognitive performance. In contrast, poor quality and short sleep increased negative affect (i.e. anger, fear, and perceived stress) and reduced life satisfaction and positive emotionality. At the brain level, poorer sleep quality and shorter sleep duration related to lower intracortical myelin in the mid-posterior cingulate cortex (p = 0.038), middle temporal cortex (p = 0.024), and anterior orbitofrontal cortex (OFC, p = 0.034) but did not significantly affect different measures of white matter integrity. Finally, lower intracortical myelin in the OFC mediated the association between poor sleep quality and negative emotionality (p < 0.05). We conclude that intracortical myelination is an important mediator of the negative consequences of poor sleep on affective behavior.

Physical Activity Level, Insomnia and Related Impact in Medical Students in Poland

BACKGROUND

Specific academic environment and time spent on learning may lead to sleep deprivation and a sedentary lifestyle. Insomnia is the most common sleep complaint. The purposes of this study were to describe the prevalence of insomnia in medical students, and to examine physical activity levels and other behavioral factors associated with insomnia in this population group.

METHODS

We included 308 medical students from Poland. The International Physical Activity Questionnaire (IPAQ) was used to assess physical activity levels and the Athens Insomnia Scale (AIS) was used to assess insomnia among students. A multifactor model of analysis was used to analyze variables related to insomnia.

RESULTS

A share of 19.2% of medical students were inactive. Insomnia was reported by 36.8% of students. In the multifactorial model, variables such as smoking cigarettes (ß = 0.21, p < 0.001), consuming energy drinks several times a month (ß = 0.21, p = 0.024), or daily stress (ß = 0.44, p < 0.001) had a negative impact on the quality of sleep of medical students.

CONCLUSIONS

Most medical students are physically active, however, approximately one-third of the medical students experience insomnia. This sleep problem is reported more often in students who experience daily stress or smoke cigarettes.

Day-to-day variability in sleep parameters and depression risk: a prospective cohort study of training physicians

While 24-h total sleep time (TST) is established as a critical driver of major depression, the relationships between sleep timing and regularity and mental health remain poorly characterized because most studies have relied on either self-report assessments or traditional objective sleep measurements restricted to cross-sectional time frames and small cohorts. To address this gap, we assessed sleep with a wearable device, daily mood with a smartphone application and depression through the 9-item Patient Health Questionnaire (PHQ-9) over the demanding first year of physician training (internship). In 2115 interns, reduced TST (b = -0.11, p < 0.001), later bedtime (b = 0.068, p = 0.015), along with increased variability in TST (b = 0.4, p = 0.0012) and in wake time (b = 0.081, p = 0.005) were associated with more depressive symptoms. Overall, the aggregated impact of sleep variability parameters and of mean sleep parameters on PHQ-9 were similar in magnitude (both r² = 0.01). Within individuals, increased TST (b = 0.06, p < 0.001), later wake time (b = 0.09, p < 0.001), earlier bedtime (b = - 0.07, p < 0.001), as well as lower day-to-day shifts in TST (b = -0.011, p < 0.001) and in wake time (b = -0.004, p < 0.001) were associated with improved next-day mood. Variability in sleep parameters substantially impacted mood and depression, similar in magnitude to the mean levels of sleep parameters. Interventions that target sleep consistency, along with sleep duration, hold promise to improve mental health.

A meta-analysis of the relationship between subjective sleep and depressive symptoms in adolescence

BACKGROUND

Adolescence is a risk period for the development of mental illness, as well as a time for pronounced change in sleep behaviour. While prior studies, including several meta-analyses show a relationship between sleep and depressive symptoms, there were many inconsistences found in the literature.

OBJECTIVE

To investigate the relationship between subjective sleep and depressive symptoms.

METHODS

Following PRISMA guidelines, we conducted a literature search that yielded forty-nine recent studies (2014-2020) with adolescent samples aged 9 to 25-year-olds, and more than double the sample size of previous meta-analyses (N = 318,256).

RESULTS

In a series of meta-analyses, we show that while several common categories of subjective sleep are associated with depressive symptoms in adolescents, the strength of this relationship varies. Measures of sleep perception: poor sleep quality (r = 0.41), insomnia (r = 0.37), sleep disturbances (r = 0.36), wake after sleep onset (r = 0.31), and daytime sleepiness (r = 0.30) correlated more strongly with depressive symptoms, than measures of sleep behaviour: sleep latency (r = 0.22), and sleep duration (r = -0.19).

CONCLUSIONS

These findings suggest that in studies of depressive symptoms it may be important to assess an adolescent's perception about their sleep, in addition to their sleep/wake behaviours.

Relationship between Mental Health, the CLOCK Gene, and Sleep Quality in Surgical Nurses: A Cross-Sectional Study

Nursing is a high-risk occupation with high exposure to stress. The physical and mental health of nurses is directly related to the quality of medical services. Therefore, the sleep quality of nurses should not be ignored. In this study, the method of cluster random sampling was adopted from May to September 2019, and a questionnaire survey was conducted among 521 surgical nurses from five affiliated hospitals of Xinjiang Medical University. The relationship between mental health and sleep quality was analyzed, and 20% of the participants with sleep disorders were randomly selected. The sleep disorders used 1 : 1 matching, finally providing a sample with 60 cases and 60 controls for measurement of the CLOCK gene (rs1801260, rs6850524), to analyze the effect of the interaction between mental health and the CLOCK gene on sleep. The mental health and sleep quality of the surgical nurses were evaluated using the Symptom Checklist 90 (SCL-90) and Pittsburgh Sleep Quality Index (PSQI). The study found that surgical nurses had poor sleep, and there were differences associated with age, years working, frequency of night shifts, and incidence of sleep disorders under marital status (p < 0.05). The PSQI scores of the positive psychological symptoms were higher than those of the negative psychological symptoms. The rank sum test was used to compare the sleep quality scores of different genotypes in CLOCK rs1801260 and rs6850524; the results indicated that the PSQI scores were different among different genotypes at the rs1801260 and rs6850524 loci. The logistic regression results suggested that CLOCK gene rs1801260 (TC) and positive psychological symptoms were influential factors for sleep disorders, and the interaction of positive psychological symptoms∗rs1801260 (TT) was a risk factor for sleep disorders (OR = 10.833, 95% CI: 2.987-39.288). The sleep quality of nurses is not only affected by demographic characteristics but also affected by mental health status and the CLOCK gene.

Association of job stress, CLOCK gene polymorphism and their interaction with poor sleep quality

Job stress and the Circadian Locomotor Output Cycles Kaput (CLOCK) gene could affect circadian rhythm and sleep quality. The main aim of our present study was to investigate the association of job stress, CLOCK gene polymorphism and their interaction with sleep quality in a non-clinical Chinese Han population, which has not been reported to date. Using a cross-sectional design, 450 subjects were recruited in Beijing. Sleep quality was measured with the Pittsburgh Sleep Quality Index (PSQI) and job stress was measured with the Work Stress Scale. CLOCK gene rs11932595 polymorphism was genotyped in 297 blood samples. Correlation analysis showed a close but different association of high job stress with the PSQI and its components. Analysis of variance showed significant main effects of the CLOCK gene rs11932595 polymorphism. G-allele carriers had a higher score in the PSQI, sleep duration, sleep latency and sleep disturbances. Further interaction analyses showed an ordinal interaction on sleep duration, and a disordinal interaction on daytime dysfunction. Specifically, G-allele carriers had poorer sleep duration than AA homozygotes when in high job stress, while the two subgroups displayed similar sleep duration when in low job stress, conforming to the diathesis-stress model. In comparison to G-allele carriers, AA homozygotes experienced less daytime dysfunction when in low job stress whereas more daytime dysfunction when in high job stress, fitting with the differential susceptibility model. As genetic links have been revealed, our investigation might be conducive for elucidating aetiological factors for sleep quality and targets for implementing interventions to attain good sleep quality.

Intraindividual variability in sleep and comorbid medical and mental health conditions

STUDY OBJECTIVES

Intraindividual variability (IIV) in sleep may be a risk factor for disease above the influence of mean sleep. Associations between IIV in sleep and risk for a comprehensive set of common medical and mental health conditions have not been assessed in a representative sample.

METHODS

This study examined mean and IIV in total sleep time (TST), sleep quality (SQ), sleep efficiency (SE), and circadian midpoint (CM) in 771 adults recruited for an epidemiological study. Participants completed 14 days of sleep diaries to assess TST, SQ, SE, and CM, after which they reported on medical conditions and mental health symptoms. Data were analyzed using logistic regression, and models controlled for gender, body mass index, age, and race.

RESULTS

Lower mean TST, SQ, and SE were related to increased odds of having gastrointestinal problems, depression, and anxiety. IIV in TST was related to increased odds of having neurological, breathing, and gastrointestinal problems, as well as pain and depression; all results held controlling for mean sleep and adjusting for false discovery rate. IIV in SQ and SE was not associated with odds of having any medical or mental health conditions after adjusting for false discovery rate, nor was IIV in CM or mean CM.

CONCLUSIONS

Confirming previous research, mean TST, SQ, and SE are related to risk for gastrointestinal problems, depression, and anxiety. IIV in TST may be a unique facet of disturbed sleep that is associated with increased risk for a diverse cluster of medical and mental health conditions.

The Interplay Between Tobacco Dependence and Sleep Quality Among Young Adults

Objective/Background: Sleep disturbances are considered among the negative consequences of smoking. However, the relationship between sleep quality and smoking among young adults, a population in which the prevalence of smoking is highest, has scarcely been examined. The current study aimed at examining differences in sleep indices, assessed by both subjective and objective (actigraphy) measures, between smokers and nonsmokers, and whether such differences are associated with levels of nicotine dependence. Participants: Eighty-six young (19-28 years old) volunteers, of them 46 nonsmokers (69.6% women) and 40 regular smokers (70.0% women) smoking at least 10 cigarettes a day. Methods: The participants completed the State-Trait Anxiety Inventory, Beck Depression Inventory, Brief Questionnaire on Smoking Urges, the Fagerstrom Test for Nicotine Dependence, and the Pittsburgh Sleep Quality Index. Their sleep was monitored objectively for one week using an actigraph. Results: Smokers' self-reported sleep quality was similar to that of nonsmokers. However, actigraphy data pointed to lower sleep continuity in smokers compared to nonsmokers as reflected by increased wake time after sleep onset (Mean ± SD: 18.56 ± 15.29 vs. 11.21 ± 11.19, p < .01) and decreased sleep efficiency (Mean ± SD: 95.63 ± 3.53 vs. 97.23 ± 2.62, p < .012). Total sleep time and sleep onset latency did not differ between the groups. Notably, severity of nicotine dependence was negatively associated with sleep efficiency (β = -.32; p < .05). Conclusion: Young adult smokers have lower sleep continuity without necessarily subjectively experiencing their sleep as poor. Nevertheless, their lower sleep continuity is related to their level of nicotine dependence.

Sleep as a Target for Optimized Response to Smoking Cessation Treatment

Declining national rates of current tobacco use to an all-time low of 15.1% represents a public health victory. Undermining this progress, however, are smoking rates of up to 50% among high-risk, low-income populations. Current FDA-approved treatments for nicotine dependence are ineffective with between 70-95% of treatment-seekers relapsing within the first year of attempted abstinence. Thus, identification of novel intervention targets to optimize response to currently available treatments for nicotine dependence is a critical next step. One such target may be sleep insomnia. Insomnia is a clinically verified nicotine withdrawal symptom but, to date, addressing insomnia or other sleep disturbance symptoms as an adjunctive smoking cessation therapy has yet to be fully considered. To this end, this manuscript presents a narrative review of: (1) sleep continuity and architecture in smokers versus nonsmokers; (2) effects of nicotine abstinence on sleep; (3) possible mechanisms linking sleep with smoking cessation outcomes; (4) plausible adjunctive sleep therapies to promote smoking cessation; (5) possible treatments for unhealthy sleep in smokers; and (6) directions for future research. Taken together, this will provide conceptual support for sleep therapy as an adjunctive treatment for smoking cessation.

Implications

This narrative literature review presents a comprehensive discussion of the relationship between habitual sleep and cigarette smoking. The extent to which unhealthy sleep in smokers may be a viable intervention target for promoting response to smoking cessation treatment is considered. Ultimately, this review provides conceptual support for sleep therapy as an adjunctive treatment for smoking cessation.

Circadian clock genes and circadian phenotypes in patients with myocardial infarction

PURPOSE

Human physiological activities and diseases are under the control of the circadian rhythm. There are strong epidemiological associations between disrupted circadian rhythms, sleep duration and diseases. Sleep disorders are associated with vascular outcomes, such as myocardial infarction (MI).

METHODS

We conducted an association study of genotype-phenotype interaction, to determine which circadian clock gene variants might be associated with the circadian phenotypes in patients with MI. In the present study, we analyzed the allele frequencies of 10 single nucleotide polymorphisms in four circadian clock genes in two independent samples: MI patients and controls. Chronotype was assessed using the Morningness - Eveningness Questionnaire (MEQ) and daytime sleepiness using the Epworth Sleepiness Scale (ESS).

RESULTS

Chronotype was associated with the ARNTL genetic variant rs12363415 in MI patients. The polymorphisms rs11932595 of the CLOCK gene and rs934945 of the PER2 gene were associated with daytime sleepiness in the patient group.

CONCLUSION

Our data suggest that genetic variations in some circadian clock genes might be related to circadian phenotype (i.e., chronotype and daytime sleepiness) in patients with myocardial infarction.

Love is a physiological motivation (like hunger, thirst, sleep or sex)

The multitude of terms associated with love has given rise to a false perception of love. In this paper, only maternal and romantic love are considered. Love is usually regarded as a feeling, motivation, addiction, passion, and, above all, an emotion. This confusion has consequences in the lives of human beings, leading not only to divorces, suicides, femicides but possibly also to a number of mental illnesses and suffering. Therefore, it is crucial to first clarify what is meant by emotion, motivation and love. This work aims to finally place love within the category of physiological motivations, such as hunger, thirst, sleep, or sex, on the basis that love is also essential for human survival, especially in childhood. Love is presented from an evolutionary perspective. Some other similarities between love and other physiological motivations are pointed out, such as its importance for appropriate human development, both its ontogeny and its permanence, and the long-lasting consequences of abuse and neglect. There are summarized reasons that account for this, such as the fact that physiological motivations are essential for survival and that love is an essential motivation for the survival of human offspring. Other reasons are that minimum changes in the quantity and quality of love alters development, that there can be a variety of neurophysiological and behavioural states within a motivation, and that motivations (also love) appear and change throughout development. Also, motivations and love sometimes may lead to an addictive behaviour. Finally, it is recognized that once physiological motivations (and love) appear, they become permanent. In a third section, some potential social, cultural, clinical and scientific consequences of the proposed consideration of love as a motivation are discussed. Accordingly, love's recognition as a motivation in the clinical field would imply a better understanding of its disorders and its inclusion in classifications manuals such as The Diagnostic and Statistical Manual of Mental Disorders (DSM), or in the International Classification of Diseases (ICD). Considering love as a motivation rather than an emotion could also impact the results of scientific research (an example is included). A comprehensive understanding of these questions could potentially allow for a new therapeutic approach in the treatment of mental illness, while offering an all-inclusive evolutionary explanation of cultural phenomena such as the origin and diffusion of both language and art. Love should be understood as a physiological motivation, like hunger, sleep or sex, and not as an emotion as it is commonly considered.

Advanced melatonin onset relative to sleep in women with unmedicated major depressive disorder

Studies on circadian timing in depression have produced variable results, with some investigations suggesting phase advances and others phase delays. This variability may be attributable to differences in participant diagnosis, medication use, and methodology between studies. This study examined circadian timing in a sample of unmedicated women with and without unipolar major depressive disorder. Participants were aged 18-28 years, had no comorbid medical conditions, and were not taking medications. Eight women were experiencing a major depressive episode, nine had previously experienced an episode, and 31 were control participants with no history of mental illness. Following at least one week of actigraphic sleep monitoring, timing of salivary dim light melatonin onset (DLMO) was assessed in light of <1 lux. In currently depressed participants, melatonin onset occurred significantly earlier relative to sleep than in controls, with a large effect size. Earlier melatonin onset relative to sleep was also correlated with poorer mood for all participants. Our results indicate that during a unipolar major depressive episode, endogenous circadian phase is advanced relative to sleep time. This is consistent with the early-morning awakenings often seen in depression. Circadian misalignment may represent a precipitating or perpetuating factor that could be targeted for personalized treatment of major depression.

Predicting the Effect of a Predictor When Controlling for Baseline

The present simulation study indicates that a method where the regression effect of a predictor (X) on an outcome at follow-up (Y1) is calculated while adjusting for the outcome at baseline (Y0) can give spurious findings, especially when there is a strong correlation between X and Y0 and when the test-retest correlation between Y0 and Y1 is relatively weak. Researchers wishing to avoid spurious findings and Type 1 errors should be aware of this phenomenon and are recommended to verify found effects by an unadjusted effect of X on the Y1-Y0 difference.

Sleep and eating disorders among adults enrolled in a commercial weight loss program: associations with self-report and objective sleep measures

PURPOSE

Some research suggests that eating disorders are related to poor sleep health. To increase knowledge on the relation between sleep and eating disorders, we used a multi-method approach to examine associations between sleep, chronotype, and eating disorder psychopathology.

METHODS

We investigated associations between ED psychopathology, both diagnostic categories (ascertained through self-report data) and dimensional measures, and self-report and ambulatory measures of sleep. Adults currently enrolled in a commercial weight loss program completed self-report measures as well as 1 week of ambulatory sleep monitoring and sleep diaries.

RESULTS

Participants with full- or sub-threshold bulimia nervosa and binge eating disorder reported significantly lower subjective sleep health and greater eveningness. Additionally, greater severity of eating disorder psychopathology was associated with lower subjective sleep health and greater eveningness. Eating disorder psychopathology was generally not related to objective sleep measures. Regarding diary measures, global eating disorder psychopathology was negatively correlated with subjective reports of feeling rested.

CONCLUSION

Eating disorder psychopathology is associated with participants' subjective sense of sleep quality, but appears to have little relation to objective sleep characteristics. Level of evidence Level V, descriptive study.

Sleep in Offspring of Parents With Mood Disorders

Background: Sleep problems in childhood are an early predictor of mood disorders among individuals at high familial risk. However, the majority of the research has focused on sleep disturbances in already diagnosed individuals and has largely neglected investigating potential differences between weeknight and weekend sleep in high-risk offspring. This study examined sleep parameters in offspring of parents with major depressive disorder or bipolar disorder during both weeknights and weekends. Methods: We used actigraphy, sleep diaries, and questionnaires to measure several sleep characteristics in 73 offspring aged 4-19 years: 23 offspring of a parent with major depressive disorder, 22 offspring of a parent with bipolar disorder, and 28 control offspring. Results: Offspring of parents with major depressive disorder slept, on average, 26 min more than control offspring on weeknights (95% confidence interval, 3 to 49 min, p = 0.027). Offspring of parents with bipolar disorder slept, on average, 27 min more on weekends than on weeknights compared to controls, resulting in a significant family history × weekend interaction (95% confidence interval, 7 to 47 min, p = 0.008). Conclusions: Sleep patterns in children and adolescents were related to the psychiatric diagnosis of their parent(s). Future follow-up of these results may clarify the relations between early sleep differences and the risk of developing mood disorders in individuals at high familial risk.

Psychometric Analysis Of The Sleep Hygiene Index And Correlation With Stress And Anxiety Among Saudi University Students

AIMS

This study aimed to assess the psychometric properties of the Sleep Hygiene Index (SHI) instrument in screening poor sleep hygiene practices among Saudi university students. As a secondary goal, the association of sleep hygiene practices with stress and anxiety scores were assessed.

METHODS

Two-hundred and four healthy college and university students aged 18 to 25 years participated in this cross-sectional questionnaire-based survey. Participants were asked to complete the English version of the SHI instrument, the Perceived Stress Scale (PSS-10), the Generalized Anxiety Disorder (GAD-7) scale, and to provide demographic details.

RESULTS

The average scores for the SHI, the GAD-7, and the PSS-10 were 6.6, 5.3, and 16.2, respectively. The internal consistency of the SHI was adequate (McDonald's Omega 0.76). The corrected item-total correlations for all the items were fair (range, 0.31-0.50). A statistically significant positive correlation/association of the SHI scores with the PSS score, GAD-7, and self-reported poor sleep were obtained in this sample of Saudi university students. Factor analysis favored a 4-factor model of the SHI in the study sample.

CONCLUSION

The SHI scale demonstrated an adequate level of internal consistency as a self-reported instrument in the assessment of sleep hygiene among Saudi university students. In addition, poor sleep hygiene was correlated with stress and anxiety scores.

The association study of CLOCK gene polymorphisms with antidepressant effect in Chinese with major depressive disorder

AIM

Major depressive disorder (MDD) is a common psychiatric disorder with a complicated pathogenesis and genetic predisposition. The objective of this article is to explore the relationship between the four SNPs of circadian locomotor output cycles kaput (CLOCK) gene (rs11932595, rs12504300, rs3805148, rs534654) and the efficacy of antidepressants. Materials & methods: This study enrolled a total of 600 patients, who met the DSM-V diagnostic criteria for MDD. All subjects were treated with single selective serotonin reuptake inhibitors. The HAMD₁₇ and adverse reaction scale (TESS/UKU) were used to assess the efficacy of antidepressants and adverse effects. The PCR and DNA sequencing analysis were used to genotype loci of CLOCK gene.

RESULTS

The antidepressants efficacy of subjects with rs11932595 AA genotype was significantly higher than those with GG+GA genotypes (p = 0.035). But this p-value was not significant after false discovery rate (FDR) adjustment.

CONCLUSION

The variant of CLOCK gene may be associated with the efficacy of selective serotonin reuptake inhibitors in Chinese Han MDD patients.

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

OBJECTIVE

Insomnia 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).

METHODS

This 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).

RESULTS

MANCOVA 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.

CONCLUSIONS

Greater 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.

Sleep, Sleep Disorders, and Circadian Health following Mild Traumatic Brain Injury in Adults: Review and Research Agenda

A rapidly expanding scientific literature supports the frequent co-occurrence of sleep and circadian disturbances following mild traumatic brain injury (mTBI). Although many questions remain unanswered, the preponderance of evidence suggests that sleep and circadian disorders can result from mTBI. Among those with mTBI, sleep disturbances and clinical sleep and circadian disorders contribute to the morbidity and long-term sequelae across domains of functional outcomes and quality of life. Specifically, along with deterioration of neurocognitive performance, insufficient and disturbed sleep can precede, exacerbate, or perpetuate many of the other common sequelae of mTBI, including depression, post-traumatic stress disorder, and chronic pain. Further, sleep and mTBI share neurophysiologic and neuroanatomic mechanisms that likely bear directly on success of rehabilitation following mTBI. For these reasons, focus on disturbed sleep as a modifiable treatment target has high likelihood of improving outcomes in mTBI. Here, we review relevant literature and present a research agenda to 1) advance understanding of the reciprocal relationships between sleep and circadian factors and mTBI sequelae and 2) advance rapidly the development of sleep-related treatments in this population.

Mechanisms underlying the association between insomnia, anxiety, and depression in adolescence: Implications for behavioral sleep interventions

There is robust evidence of an association between insomnia, anxiety, and depression in adolescence. The aim of this review is to describe and synthesize potential mechanisms underlying this association and explore implications for the design of adolescent behavioral sleep interventions. Specifically, we examine whether insomnia symptoms are a mechanism for the development of internalizing symptoms in adolescence and whether sleep interventions are an effective treatment for both insomnia and internalizing symptoms in adolescence because they target the shared mechanisms underlying these disorders. Research using different methodologies points to the role of sequential, parallel, and interacting mechanisms. In this paper, we review a wide range of relevant biological (i.e., polymorphisms and dysregulation in serotonin, dopamine, and circadian clock genes; alterations in corticolimbic and mesolimbic brain circuits; cortisol reactivity to stress; inflammatory cytokine dysregulation; biased memory consolidation; changes in sleep architecture), psychological (i.e., cognitive inflexibility, interpretational biases, judgment biases, negative attribution styles, worry, rumination, biased attention to threat, dysfunctional beliefs and attitudes about sleep, misperception of sleep deficit), and social mechanisms (i.e., reduced and impaired social interactions, unhelpful parenting behaviors, family stress) and propose an integrative multilevel model of how these phenomena may interact to increase vulnerability to both insomnia and internalizing disorders. Several 'biopsychosocial' mechanisms hold promise as viable treatment targets for adolescent behavioral sleep interventions, which may reduce both insomnia and internalizing symptoms.

Quality of Sleep and Depression in College Students: A Systematic Review

Background

Nowadays, sleep-related problems are a prevalent occurrence among university students. Poor sleep quality is one of the most studied aspects of sleep complaints, affecting from 10% to 50% of this population. Poor sleep quality consequences are many and have a profound impact in the student's psychobiological health. University students live through a period of psychological challenge and adaptation, since the transition from high school to professional life. Abrupt autonomy challenges students to deal with many choices, from their academic and social life to their intimate habits. Frequently, sleep hygiene is neglected, or they are unable to use proper coping mechanisms, resulting in disturbing consequences that could impact their lives as adults. Research has found a significant association between sleep quality and depression or depressive symptoms, but this relationship is still somewhat difficult to interpret.

Objective

The objective of this review is to appraise the current knowledge around the relationship of sleep with depression in this group of young adults. Data Source: Articles included in Medline database.

Methods

After a careful search, the articles selected aimed mainly college students. The studies had sleep quality and depression objectively assessed, focused in the relationship between both, and addressed possible influencing factors.

Results

The current literature still supports a bidirectional relationship between sleep and depression, however, the importance of sleep quality is becoming a very relevant variable.

Conclusion

Education and the application of policies regarding sleep hygiene may prevent, in some cases, the development of depression and improve the quality of sleep in other cases. Future research should clarify the relationship between sleep problems and depression in a way they could be prevented or, at least, minimalized with effective and achievable interventions.

Genetic Markers of Sleep and Sleepiness

The circadian clock interacts with the sleep homeostatic drive in humans. Chronotype and sleep parameters show substantial heritability, underscoring a genetic component to these measures. This article reviews the genetic underpinnings of chronotype and of sleep, including sleepiness, sleep quality and latency, and sleep timing and duration in healthy adult sleepers, drawing on candidate gene and genome-wide association studies. Notably, both circadian and noncircadian genes associate with individual differences in chronotype and in sleep parameters. The article concludes with a brief discussion of future research directions.

The prevalence and association of stress with sleep quality among medical students

Introduction: Medical students tend to reduce their sleep, in an effort to adjust and cope with their workload and stressful environment. This study estimated the prevalence of and the relationship between poor sleep quality and stress among medical students.

Methods: This cross-sectional study was conducted using a stratified random sample of male and female medical students in King Saud bin Abdulaziz University for Health Sciences in Riyadh, Saudi Arabia. A self-administered questionnaire was distributed to assess sleep quality using the Pittsburgh Sleep Quality Index, and the stress level by using the Kessler Psychological Distress Scale.

Results: A high prevalence of poor sleep quality (76%) and stress (53%) were found, with a statistically significant association (p < 0.001). Logistic regression indicated that students who are not suffering from stress are less likely to have poor sleep quality (OR = 0.28, p < 0.001), and the risk of having poor sleep quality is almost four times higher in students whose cumulative grade point average (GPA) is less than 4.25 (OR = 3.83, p = 0.01).

Conclusion: The study documents a statistically significant association between stress and poor sleep quality. A recommendation for the management of medical college is to establish academic counseling centers focusing in promoting good sleep hygiene and strengthening students’ study skills and coping with their stressful environment.

Sleep Quantity and Quality during Acute Concussion: A Pilot Study

STUDY OBJECTIVES

A number of subjective and objective studies provide compelling evidence of chronic post-concussion changes in sleep, yet very little is known about the acute effects of concussion on sleep quality and quantity. Therefore, the purpose of this prospective pilot study was to use actigraphy to examine the changes in sleep quality and quantity acutely following concussion at home rather than in a hospital or sleep laboratory.

METHODS

Seventeen young adults (7 with acute concussion, 10 controls) were recruited for this study. All participants completed two 5-day testing sessions separated by 30 days from intake (controls) or day of injury (concussion). Participants wore actigraphs and kept a sleep journal. Sleep parameter outcomes included nighttime total sleep time (nTST), 24-h total sleep time (TST), wake after sleep onset (WASO), and sleep efficiency (SE). The coefficient of variation (CV) for each sleep parameter was computed for each session.

RESULTS

nTST and TST CV was significantly greater in the concussion group. There is the additional indication that individuals with a concussion may require and obtain more sleep shortly after injury and subsequently have a shorter duration of sleep at 1 mo post-injury. This pattern was not seen in the measures of sleep quality (WASO, SE).

CONCLUSIONS

Individuals with a concussion demonstrated increased nighttime sleep duration variability. This increase persisted at 1 mo post-injury and may be associated with previously documented self-reports of poor sleep quality lasting months and years after a concussion. Additionally, this increase may predispose individuals to numerous negative health outcomes if left untreated.

Analgesics Self-Medication and its Association with Sleep Quality among Medical Undergraduates

INTRODUCTION

Self medication especially with analgesics is a common practice among undergraduate medical students. Variation in analgesic self medication prevalence and pattern is often seen due to geographical and target population differences. The mutual influence of pain and sleep quality might persuade students self medication behaviour.

AIM

To assess analgesic self medication and its association with sleep quality among the medical undergraduates.

MATERIALS AND METHODS

A cross-sectional questionnaire based study was conducted from December 2015 to February 2016 among 320 medical undergraduates. The information about socio-demographic profile, symptoms, types of analgesics, source of information and reason for analgesic self medication was collected. The sleep quality of students was assessed by Pittsburgh Sleep Quality Index (PSQI). The qualitative variables were expressed as percentages. Odds Ratio (OR) with 95% Confidence Interval (CI) was also calculated. Chi-square test was used.

RESULTS

Analgesic self medication prevalence was 49.7%, more prevalence seen among males, seniors, urban residents and students of working parents. Headache (48.4%) was the most common cause and paracetamol (79.7%) was most frequent drug used, based on knowledge obtained through textbook and internet (47.1%). Mildness of symptoms (49.1%) was the most important motivation behind self medication. Analgesic use was more (57.4%) among "poor sleepers" compared to "normal sleepers" (45.2%).

CONCLUSION

Despite having easy accessibility to expert consultations, high prevalence of analgesic self medication among medical students and its association with poor sleep quality is a distressing issue. This indicates an urgent need of awareness programmes about harmful effects of self medication and healthy sleep practices.

Cognitive remission: a novel objective for the treatment of major depression?

BACKGROUND

Cognitive dysfunction in major depressive disorder (MDD) encompasses several domains, including but not limited to executive function, verbal memory, and attention. Furthermore, cognitive dysfunction is a frequent residual manifestation in depression and may persist during the remitted phase. Cognitive deficits may also impede functional recovery, including workforce performance, in patients with MDD. The overarching aims of this opinion article are to critically evaluate the effects of available antidepressants as well as novel therapeutic targets on neurocognitive dysfunction in MDD.

DISCUSSION

Conventional antidepressant drugs mitigate cognitive dysfunction in some people with MDD. However, a significant proportion of MDD patients continue to experience significant cognitive impairment. Two multicenter randomized controlled trials (RCTs) reported that vortioxetine, a multimodal antidepressant, has significant precognitive effects in MDD unrelated to mood improvement. Lisdexamfetamine dimesylate was shown to alleviate executive dysfunction in an RCT of adults after full or partial remission of MDD. Preliminary evidence also indicates that erythropoietin may alleviate cognitive dysfunction in MDD. Several other novel agents may be repurposed as cognitive enhancers for MDD treatment, including minocycline, insulin, antidiabetic agents, angiotensin-converting enzyme inhibitors, S-adenosyl methionine, acetyl-L-carnitine, alpha lipoic acid, omega-3 fatty acids, melatonin, modafinil, galantamine, scopolamine, N-acetylcysteine, curcumin, statins, and coenzyme Q10. The management of cognitive dysfunction remains an unmet need in the treatment of MDD. However, it is hoped that the development of novel therapeutic targets will contribute to 'cognitive remission', which may aid functional recovery in MDD.

Body Mass Index Moderates the Association between Sleep Quality and Vigilance on a Test of Inhibitory Control

OBJECTIVE

Sleep problems are common among college students and related to numerous adverse outcomes including impaired cognitive performance. Obesity may confer an elevated risk of cognitive deficits with poor sleep given its relationship with poorer sleep quality and impaired cognition. Thisstudy examined whether the relationship between reduced sleep quality and poorer vigilance and inhibitory control were moderated by elevated body mass index (BMI).

METHOD

Participants were 85 college students who completed a computerized task of inhibitory control that required vigilance (go/no-go [GNG] task) and the Pittsburgh Sleep Quality Index, a measure of sleep quality.

RESULTS

Poor sleep quality was observed in 63.5% of the sample and was related to more omission errors on the GNG task and increased BMI. Results further revealed that BMI moderated the relationship between sleep quality and performance on the GNG task such that individuals in the severely obese range of BMI had more omission errors with poorer sleep quality, while there was no association between sleep and GNG performance among normal weight and overweight individuals.

CONCLUSIONS

These findings highlight the likely contribution of obesity to decreased vigilance with poor sleep. Future research is needed to confirm these findings using objective measures of sleep quality (e.g., actigraphy, polysomnography).