Circadian time of morning light administration and therapeutic response in winter depression

Circadian markers as a predictor of response in the treatment of depression-A systematic review

Despite many available treatment options for depression, response rates remain suboptimal. To improve outcome, circadian markers may be suitable as markers of treatment response. This systematic review provides an overview of circadian markers that have been studied as predictors of response in treatment of depression. A search was performed (EMBASE, PUBMED, PSYCHINFO) for research studies or articles, randomized controlled trials and case report/series with no time boundaries on March 2, 2024 (PROSPERO: CRD42021252333). Other criteria were; an antidepressant treatment as intervention, treatment response measured by depression symptom severity and/or occurrence of a clinical diagnosis of depression and assessment of a circadian marker at baseline. 44 articles, encompassing 8,772 participants were included in the analysis. Although additional research is needed with less variation in types of markers and treatments to provide definitive recommendations, circadian markers, especially diurnal mood variation and chronotype, show potential to implement as response markers in the clinic.

Sleep-wake timing and chronotype in perinatal periods: longitudinal changes and associations with insomnia symptoms, sleep-related impairment, and mood from pregnancy to 2 years postpartum

Across the perinatal transition, existing research focuses mainly on significant changes in sleep duration and quality, neglecting sleep timing. This study investigated change trajectories of sleep timing and chronotype from late pregnancy to 2 years postpartum and examined longitudinal associations of chronotype with symptoms of insomnia, daytime sleep-related impairment, and mood. Data were from a two-arm randomised controlled trial testing parent-focused wellbeing interventions. Participants were a community sample of nullipara without severe sleep/mental health conditions. Participants self-reported bedtime, rise-time, chronotype, insomnia symptoms, sleep-related impairment, depression, and anxiety at seven time points: gestation Weeks 30 and 35, and postpartum Months 1.5, 3, 6, 12 and 24. Trajectories were estimated using mixed-effects models with continuous time, quadratic splines, and a knot at childbirth, controlling for age and group allocation. A total of 163 participants (mean [SD] age 33.35 [3.42] years) took part. Bedtime and rise-times delayed during late pregnancy (~8 and ~20 min, respectively) but became progressively earlier (~20 and ~60 min, respectively) over the 2 postpartum years. Chronotype became more eveningness in late pregnancy, and more morningness after childbirth, however changes were small. Controlling for sleep duration and efficiency, greater morningness was associated with significantly less symptoms of insomnia and sleep-related impairment over time (all p < 0.001); longitudinal associations between chronotype and symptoms of depression and anxiety were non-significant (all p > 0.65). Sleep-wake timing and chronotype became progressively earlier from pregnancy to 2 years postpartum. Morningness chronotype may be sleep-protective during the transition from pregnancy to parenthood. Mechanisms underlying these associations require further research.

Patterns in behavioural sleep variables and social jetlag in elderly people of Western Odisha

In humans, sleep is an essential physiological process for life and survival. The main objective of the current study is to determine the behavioural sleep patterns and social jetlag in elderly adults. The second objective is to define the relationship among subjective sleep quality, mid-sleep timings, social jetlag, and sunlight exposure. We recruited 945 female and 1047 male participants aged ≥ 60 years from 65 rural villages in the Sambalpur district of Odisha, India. The Munich Chrono Type Questionnaire (MCTQ) is a self-reported questionnaire that measures a person's behavioral sleep variables, including social jetlag and chronotype, whereas the Pittsburgh Sleep Quality Index (PSQI) measures the subjective sleep quality of an individual. We employed MCTQ and PSQI to obtain behavioral sleep variables and subjective sleep quality in the recruited subjects. The behavioral sleep variables were compared using a paired t-test on both work and work-free days. In addition, the behavioral sleep variables as a function of gender were compared using an independent Student's t-test. In the current study, most of the elderly individuals reported both midpoint of sleep on workdays (MSW) and midpoint of sleep on work-free days (MSF) between 00:01-03:00. The averages of mid-sleep timings between workdays and work-free days were not statistically significant. Data on MSFsc (midpoint of sleep on work-free days sleep corrected) indicated that most elderly adults (99.6%) are morning type; they go to bed early and wake up early. The elderly participants from the rural population of Sambalpur district in western Odisha had the least social jetlag and exhibited good subjective sleep quality. It would be worthwhile to find out the determinants of these positive features apropos social jetlag and behavioural sleep patterns.

Circadian rhythms and mood disorders: Time to see the light

The importance of time is ever prevalent in our world, and disruptions to the normal light/dark and sleep/wake cycle have now become the norm rather than the exception for a large part of it. All mood disorders, including seasonal affective disorder (SAD), major depressive disorder (MDD), and bipolar disorder (BD), are strongly associated with abnormal sleep and circadian rhythms in a variety of physiological processes. Environmental disruptions to normal sleep/wake patterns, light/dark changes, and seasonal changes can precipitate episodes. Moreover, treatments that target the circadian system have proven to be therapeutic in certain cases. This review will summarize much of our current knowledge of how these disorders associate with specific circadian phenotypes, as well as the neuronal mechanisms that link the circadian clock with mood regulation. We also discuss what has been learned from therapies that target circadian rhythms and how we may use current knowledge to develop more individually designed treatments.

Associations of the timing of sleep and meals with the presence of gastroesophageal reflux disease in community-dwelling women in Japan

BACKGROUND

It has been suspected that circadian rhythms may play a part in the pathogenesis of gastrointestinal diseases including gastroesophageal reflux disease (GERD). The present study aimed to examine the cross-sectional association of the timing of sleep and meals with the presence of GERD in community-dwelling women in Japan.

METHODS

In total, 605 women responded to a self-administered questionnaire asking for information on GERD symptoms, sleep habits, sleep disturbances and the timing of meals. GERD symptoms were evaluated using the Frequency Scale for the Symptoms of GERD, and participants with a score of more than seven points were classified as having GERD.

RESULTS

In total, 104 (17.2%) women were found to have GERD. Later bedtime on both weekdays and weekends and later midpoint of sleep were significantly associated with the odds ratios (OR) of GERD after controlling for covariates: ORs for each 1 h delay were 1.31 (95% confidence interval [CI] = 1.03-1.68), 1.38 (95% CI = 1.08-1.75) and 1.43 (95% CI = 1.06-1.95). Having lunch at irregular times was significantly associated with the increased OR of GERD (1.99; 95% CI = 1.02-3.91). Longer overnight fasting duration and longer time intervals from the midpoint of sleep to breakfast and lunch were significantly associated with decreased OR of GERD (ORs for each 1 h increase were 0.73 [95% CI = 0.56-0.95], 0.64 [95% CI = 0.46-0.88] and 0.70 [95% CI = 0.51-0.96]).

CONCLUSIONS

These data suggest that the timing of sleep and timing of meals relative to the sleep/wake cycle are associated with the presence of GERD.

Melatonin secretion patterns are associated with cognitive vulnerability and brain structure in bipolar depression

Circadian rhythm disruption is a core symptom of bipolar disorder (BD), also reflected in altered patterns of melatonin release. Reductions of grey matter (GM) volumes are well documented in BD. We hypothesized that levels and timing of melatonin secretion in bipolar depression could be associated with depressive psychopathology and brain GM integrity. The onset of melatonin secretion under dim light conditions (DLMO) and the amount of time between DLMO and midsleep (i.e. phase angle difference; PAD) were used as circadian rhythm markers. To study the time course of melatonin secretion, an exponential curve fitting the melatonin values was calculated, and the slope coefficients (SLP) were obtained for each participant. Significant differences were found between HC and BD in PAD measures and melatonin profiles. Correlations between PAD and depressive psychopathology were identified. Melatonin secretion patterns were found to be associated with GM volumes in the Striatum and Supramarginal Gyrus in BD. Our findings emphasized the role of melatonin secretion role as a biological marker of circadian synchronization in bipolar depression and provided a novel insight for a link between melatonin release and brain structure.

Change in Seasonal Beliefs Mediates the Durability Advantage of Cognitive-Behavioral Therapy Over Light Therapy for Winter Depression

In treating an acute episode of winter depression, cognitive-behavioral therapy for seasonal affective disorder (CBT-SAD) and light therapy are comparably efficacious, with improvement in depression symptoms during CBT-SAD mediated by reduced seasonal beliefs (i.e., maladaptive thoughts about the seasons, light availability, and weather). Here, we tested whether the enduring benefit of CBT-SAD over light therapy following treatment is associated with offsetting seasonal beliefs during CBT-SAD. Currently depressed adults with Major Depression, Recurrent with Seasonal Pattern (N = 177) were randomized to 6 weeks of light therapy or group CBT-SAD and followedup one and two winters after treatment. Outcomes measured during treatment and at each follow-up included depression symptoms on the Structured Clinical Interview for the Hamilton Rating Scale for Depression-SAD Version and Beck Depression Inventory-Second Edition. Candidate mediators measured at pre-, mid-, and posttreatment were SAD-specific negative cognitions (Seasonal Beliefs Questionnaire; SBQ); general depressogenic cognitions (Dysfunctional Attitudes Scale; DAS); brooding rumination (Ruminative Response Scale-Brooding subscale; RRS-B); and chronotype (Morningness-Eveningness Questionnaire; MEQ). Latent growth curve mediation models found a significant positive path from treatment group to the slope of SBQ during treatment, with CBT-SAD showing larger improvements in seasonal beliefs with overall change in seasonal beliefs in the medium-effect range, and significant positive paths from SBQ slope to depression scores at the first and second winter follow-ups, indicating greater change towards more flexible seasonal beliefs during active treatment was associated with less severe depression symptoms following treatment. Estimated indirect effects (treatment group → SBQ change * SBQ change → outcome) were also significant at each follow-up for each outcome with βindirect ranging from .091 to .162. Models also found significant positive paths from treatment group to the slope of MEQ and RRS-B during treatment, with light therapy showing a greater increase in "morningness" and CBT-SAD showing a greater decrease in brooding during active treatment; however, neither construct emerged as a mediator of follow-up depression scores. Change in seasonal beliefs during treatment mediates both the acute antidepressant and long-term effects of CBT-SAD and explains lower depression severity following CBT-SAD relative to light therapy.

Circadian Disruption and Mental Health: The Chronotherapeutic Potential of Microbiome-Based and Dietary Strategies

Mental illness is alarmingly on the rise, and circadian disruptions linked to a modern lifestyle may largely explain this trend. Impaired circadian rhythms are associated with mental disorders. The evening chronotype, which is linked to circadian misalignment, is a risk factor for severe psychiatric symptoms and psychiatric metabolic comorbidities. Resynchronization of circadian rhythms commonly improves psychiatric symptoms. Furthermore, evidence indicates that preventing circadian misalignment may help reduce the risk of psychiatric disorders and the impact of neuro-immuno-metabolic disturbances in psychiatry. The gut microbiota exhibits diurnal rhythmicity, as largely governed by meal timing, which regulates the host's circadian rhythms. Temporal circadian regulation of feeding has emerged as a promising chronotherapeutic strategy to prevent and/or help with the treatment of mental illnesses, largely through the modulation of gut microbiota. Here, we provide an overview of the link between circadian disruption and mental illness. We summarize the connection between gut microbiota and circadian rhythms, supporting the idea that gut microbiota modulation may aid in preventing circadian misalignment and in the resynchronization of disrupted circadian rhythms. We describe diurnal microbiome rhythmicity and its related factors, highlighting the role of meal timing. Lastly, we emphasize the necessity and rationale for further research to develop effective and safe microbiome and dietary strategies based on chrononutrition to combat mental illness.

Associations Between Multidimensional Sleep Health Parameters and Adolescents' Self-reported Light Exposure in the Free-living Environment

The objective of this study was to characterize the associations between light exposure in the free-living environment and multiple dimensions of sleep health of typically developing adolescents. Fifty-six (29 girls, 27 boys) typically developing adolescents (mean age = 13.59, SD = 0.89, range = 12-17 years) participated. For six consecutive nights, sleep was assessed in the home environment using actigraphy. During the same period, participants were asked to fill out a daily sleep log and a daily light exposure log, and to complete questionnaires regarding their alertness and subjective sleep satisfaction. Longer self-reported exposure to daylight in the morning was associated with longer objectively measured sleep duration. Longer self-reported exposures to electronic devices in the evening were associated with later objectively measured sleep onset and offset times, shorter sleep duration, and greater day-to-day sleep variability. Longer morning exposure to outdoor light was associated with a longer sleep duration. Self-reported light exposure was not associated with sleep satisfaction, alertness/sleepiness, or sleep efficiency. Among the covariates, circadian preference accounted for the highest percentage of variance. Adolescents' sleep health is associated with the self-reported duration of exposure to daylight in the morning and to electronic devices in the evening.

Seasonality of brain function: role in psychiatric disorders

Seasonality patterns are reported in various psychiatric disorders. The current paper summarizes findings on brain adaptations associated with seasonal changes, factors that contribute to individual differences and their implications for psychiatric disorders. Changes in circadian rhythms are likely to prominently mediate these seasonal effects since light strongly entrains the internal clock modifying brain function. Inability of circadian rhythms to accommodate to seasonal changes might increase the risk for mood and behavior problems as well as worse clinical outcomes in psychiatric disorders. Understanding the mechanisms that account for inter-individual variations in seasonality is relevant to the development of individualized prevention and treatment for psychiatric disorders. Despite promising findings, seasonal effects are still understudied and only controlled as a covariate in most brain research. Rigorous neuroimaging studies with thoughtful experimental designs, powered sample sizes and high temporal resolution alongside deep characterization of the environment are needed to better understand the seasonal adaptions of the human brain as a function of age, sex, and geographic latitude and to investigate the mechanisms underlying the alterations in seasonal adaptation in psychiatric disorders.

Circadian Rhythms Disrupted by Light at Night and Mistimed Food Intake Alter Hormonal Rhythms and Metabolism

Availability of artificial light and light-emitting devices have altered human temporal life, allowing 24-hour healthcare, commerce and production, and expanding social life around the clock. However, physiology and behavior that evolved in the context of 24 h solar days are frequently perturbed by exposure to artificial light at night. This is particularly salient in the context of circadian rhythms, the result of endogenous biological clocks with a rhythm of ~24 h. Circadian rhythms govern the temporal features of physiology and behavior, and are set to precisely 24 h primarily by exposure to light during the solar day, though other factors, such as the timing of meals, can also affect circadian rhythms. Circadian rhythms are significantly affected by night shift work because of exposure to nocturnal light, electronic devices, and shifts in the timing of meals. Night shift workers are at increased risk for metabolic disorder, as well as several types of cancer. Others who are exposed to artificial light at night or late mealtimes also show disrupted circadian rhythms and increased metabolic and cardiac disorders. It is imperative to understand how disrupted circadian rhythms alter metabolic function to develop strategies to mitigate their negative effects. In this review, we provide an introduction to circadian rhythms, physiological regulation of homeostasis by the suprachiasmatic nucleus (SCN), and SCN-mediated hormones that display circadian rhythms, including melatonin and glucocorticoids. Next, we discuss circadian-gated physiological processes including sleep and food intake, followed by types of disrupted circadian rhythms and how modern lighting disrupts molecular clock rhythms. Lastly, we identify how disruptions to hormones and metabolism can increase susceptibility to metabolic syndrome and risk for cardiovascular diseases, and discuss various strategies to mitigate the harmful consequences associated with disrupted circadian rhythms on human health.

A 1-week sleep and light intervention improves mood in premenstrual dysphoric disorder in association with shifting melatonin offset time earlier

To test the hypothesis that 1 week of combined sleep and light interventions (SALI), which phase-advance (shift earlier) melatonin circadian rhythms, improves mood significantly more than phase-delay (shift later) SALI. After a 2-month diagnostic evaluation for premenstrual dysphoric disorder (PMDD per DSM-5 criteria) in a university clinical research setting, 44 participants enrolled in baseline studies were randomized in the luteal phase at home to (A) a phase-advance intervention (PAI): 1 night of late-night wake therapy (LWT: sleep 9 pm-1 am) followed by 7 days of the morning (AM) bright white light (BWL), or (B) a phase-delay intervention (PDI): 1 night of early-night wake therapy (EWT: sleep 3-7 am) plus 7 days of the evening (PM) BWL. After a month of no intervention, participants underwent the alternate intervention. Outcome measures were mood, the melatonin metabolite, 6-sulfatoxymelatonin (6-SMT), and actigraphy (to assess protocol compliance). At baseline, atypical depression correlated positively with phase delay in 6-SMT offset time (r = .456, p = .038). PAI advanced 6-SMT offset from baseline more than PDI (p < .05), and improved raw mood scores more than PDI (p < .05). As hypothesized, percent improvement in mood correlated positively with a phase advance from baseline in 6-SMT offset time (p < .001). Treatment with 1 night of advanced/restricted sleep followed by 7 days of AM BWL (PAI) was more efficacious in reducing PMDD depression symptoms than a PDI; mood improvement occurred in association with phase advance in 6-SMT offset time. Combined SALIs offer safe, efficacious, rapid-acting, well-tolerated, non-pharmacological, non-hormonal, affordable, repeatable home interventions for PMDD. Clinical Trials.gov NCT # NCT01799733.

Linking dietary intake, circadian biomarkers, and clock genes on obesity: A study protocol

Background

The prevalence of obesity continues to rise, and although this is a complex disease, the screening is made simply with the value of the Body Mass Index. This index only considers weight and height, being limited in portraying the multiple existing obesity phenotypes. The characterization of the chronotype and circadian system as an innovative phenotype of a patient's form of obesity is gaining increasing importance for the development of novel and pinpointed nutritional interventions.

Objective

The present study is a prospective observational controlled study conducted in Portugal, aiming to characterize the chronotype and determine its relation to the phenotype and dietary patterns of patients with obesity and healthy participants.

Methods

Adults with obesity (study group) and healthy adults (control group), aged between 18 and 75, will be enrolled in this study. Data will be collected to characterize the chronotype, dietary intake, and sleep quality through validated questionnaires. Body composition will also be assessed, and blood samples will be collected to quantify circadian and metabolic biomarkers.

Discussion

This study is expected to contribute to a better understanding of the impact of obesity and dietary intake on circadian biomarkers and, therefore, increase scientific evidence to help future therapeutic interventions based on chronobiology, with a particular focus on nutritional interventions.

Different levels of circadian (de)synchrony -- where does it hurt?

A network of cellular timers ensures the maintenance of homeostasis by temporal modulation of physiological processes across the day. These so-called circadian clocks are synchronized to geophysical time by external time cues (or zeitgebers). In modern societies, natural environmental cycles are disrupted by artificial lighting, around-the-clock availability of food or shiftwork. Such contradictory zeitgeber input promotes chronodisruption, i.e., the perturbation of internal circadian rhythms, resulting in adverse health outcomes. While this phenomenon is well described, it is still poorly understood at which level of organization perturbed rhythms impact on health and wellbeing. In this review, we discuss different levels of chronodisruption and what is known about their health effects. We summarize the results of disrupted phase coherence between external and internal time vs. misalignment of tissue clocks amongst each other, i.e., internal desynchrony. Last, phase incoherence can also occur at the tissue level itself. Here, alterations in phase coordination can emerge between cellular clocks of the same tissue or between different clock genes within the single cell. A better understanding of the mechanisms of circadian misalignment and its effects on physiology will help to find effective tools to prevent or treat disorders arising from modern-day chronodisruptive environments.

Different levels of circadian (de)synchrony -- where does it hurt?

A network of cellular timers ensures the maintenance of homeostasis by temporal modulation of physiological processes across the day. These so-called circadian clocks are synchronized to geophysical time by external time cues (or zeitgebers). In modern societies, natural environmental cycles are disrupted by artificial lighting, around-the-clock availability of food or shift work. Such contradictory zeitgeber input promotes chronodisruption, i.e., the perturbation of internal circadian rhythms, resulting in adverse health outcomes. While this phenomenon is well described, it is still poorly understood at which level of organization perturbed rhythms impact on health and wellbeing. In this review, we discuss different levels of chronodisruption and what is known about their health effects. We summarize the results of disrupted phase coherence between external and internal time vs. misalignment of tissue clocks amongst each other, i.e., internal desynchrony. Last, phase incoherence can also occur at the tissue level itself. Here, alterations in phase coordination can emerge between cellular clocks of the same tissue or between different clock genes within the single cell. A better understanding of the mechanisms of circadian misalignment and its effects on physiology will help to find effective tools to prevent or treat disorders arising from modern-day chronodisruptive environments.

The trilateral interactions between mammalian target of rapamycin (mTOR) signaling, the circadian clock, and psychiatric disorders: an emerging model

Circadian (~24 h) rhythms in physiology and behavior are evolutionarily conserved and found in almost all living organisms. The rhythms are endogenously driven by daily oscillatory activities of so-called "clock genes/proteins", which are widely distributed throughout the mammalian brain. Mammalian (mechanistic) target of rapamycin (mTOR) signaling is a fundamental intracellular signal transduction cascade that controls important neuronal processes including neurodevelopment, synaptic plasticity, metabolism, and aging. Dysregulation of the mTOR pathway is associated with psychiatric disorders including autism spectrum disorders (ASD) and mood disorders (MD), in which patients often exhibit disrupted daily physiological rhythms and abnormal circadian gene expression in the brain. Recent work has found that the activities of mTOR signaling are temporally controlled by the circadian clock and exhibit robust circadian oscillations in multiple systems. In the meantime, mTOR signaling regulates fundamental properties of the central and peripheral circadian clocks, including period length, entrainment, and synchronization. Whereas the underlying mechanisms remain to be fully elucidated, increasing clinical and preclinical evidence support significant crosstalk between mTOR signaling, the circadian clock, and psychiatric disorders. Here, we review recent progress in understanding the trilateral interactions and propose an "interaction triangle" model between mTOR signaling, the circadian clock, and psychiatric disorders (focusing on ASD and MD).

Elucidating treatment targets and mediators within a confirmatory efficacy trial: study protocol for a randomized controlled trial of cognitive-behavioral therapy vs. light therapy for winter depression

Background

This study is a confirmatory efficacy trial of two treatments for winter seasonal affective disorder (SAD): SAD-tailored group cognitive-behavioral therapy (CBT-SAD) and light therapy (LT). In our previous efficacy trial, post-treatment outcomes for CBT-SAD and LT were very similar, but CBT-SAD was associated with fewer depression recurrences two winters later than LT (27.3% in CBT-SAD vs. 45.6% in LT). CBT-SAD engaged and altered a specific mechanism of action, seasonal beliefs, which mediated CBT-SAD’s acute antidepressant effects and CBT-SAD’s enduring benefit over LT. Seasonal beliefs are theoretically distinct from LT’s assumed target and mechanism: correction of circadian phase. This study applies the experimental therapeutics approach to determine how each treatment works when it is effective and to identify the best candidates for each. Biomarkers of LT’s target and effect include circadian phase angle difference and the post-illumination pupil response. Biomarkers of CBT-SAD’s target and effect include decreased pupillary and sustained frontal gamma-band EEG responses to seasonal words, which are hypothesized as biomarkers of seasonal beliefs, reflecting less engagement with seasonal stimuli following CBT-SAD. In addition to determining change mechanisms, this study tests the efficacy of a “switch” decision rule upon recurrence to inform clinical decision-making in practice.

Methods

Adults with SAD (target N = 160) will be randomzied to 6-weeks of CBT-SAD or LT in winter 1; followed in winter 2; and, if a depression recurrence occurs, offered cross-over into the alternate treatment (i.e., switch from LT➔CBT-SAD or CBT-SAD➔LT). All subjects will be followed in winter 3. Biomarker assessments occur at pre-, mid-, and post-treatment in winter 1, at winter 2 follow-up (and again at mid-/post-treatment for those crossed-over), and at winter 3 follow-up. Primary efficacy analyses will test superiority of CBT-SAD over LT on depression recurrence status (the primary outcome). Mediation analyses will use parallel process latent growth curve modeling.

Discussion

Consistent with the National Institute of Mental Health’s priorities for demonstrating target engagement at the level of Research Domain Criteria-relevant biomarkers, this work aims to confirm the targets and mechanisms of LT and CBT-SAD to maximize the impact of future dissemination efforts.

Trial registration

ClinicalTrials.gov identifier: NCT03691792. Registered on October 2, 2018. 

Translation and validation of the SCRAM questionnaire in a German adolescent inpatient sample

Sleep, depressive symptoms and circadian preference are highly interconnected processes. Evidence suggests that, especially in adolescence, all processes should be considered in the assessment and treatment of patients with clinically relevant psychopathology. The SCRAM (Sleep, Circadian Rhythms, and Mood) questionnaire was developed and validated in a student sample as a promising tool to conjointly measure and separate sleep, circadian preference and depression symptomatology. The present study aims to validate a German version of the SCRAM questionnaire in an adolescent psychiatric inpatient sample. A two-step analytic strategy consisting of an exploratory factor analysis EFA followed by confirmatory factor analyses (CFA) was conducted. The EFA was run in the first half of the sample (n = 422, M = 14.92, SD = 1.67). To validate the factor structure of the EFA and the original study, two CFA`s were performed in the second half of the adolescent sample (n = 438, M = 15.07, SD = 1.68). The EFA analysis revealed a 4-factor model with 12 items. Two Sleep items and one Morningness item had cross-factor loadings. The fit indices in the CFA were good using the factor model of the original study, whereas the 4-factor model of the EFA did not converge. The German SCRAM factor model seems structurally sound in an adolescent inpatient sample, but questions remain regarding the role of diagnosis, gender, external correlates, and examining the change scores of the SCRAM scores with treatment. Before this application, further research is needed to replicate the factor structure, investigate test-retest reliability, predictive and discriminant validity and test in more generalizable samples.

CME: Light Therapy: Why, What, for Whom, How, and When (And a Postscript about Darkness)

Light therapy has become established as an evidence-based treatment for Seasonal Affective Disorder. Light impacts the timing and stability of circadian rhythms as expressed in sleep, mood, alertness, and cognition. Forty years of clinical trials and open treatment have led to guidelines for patient selection, using light alone or in combination with antidepressants (or lithium for bipolar depression). Mood and sleep disturbances can also respond to adjunct light therapy in a broader set of psychiatric, neurologic and medical illnesses. We specify criteria for choice of treatment devices: optimum dose (10,000 lux), spectrum (white light), exposure duration (30-60 minutes) and timing (early morning). Protocol adjustment requires continual monitoring with attention to rate of improvement and management of potential side effects.

Association of Delayed Sleep/Wake Rhythm with Depression During the First COVID-19 Lockdown in France

PURPOSE

The containment of the population during the COVID-19 pandemic led to the emergence or recurrence of psychiatric conditions and sleep disorders. The influence of sleep/wake rhythm on mental health is well known. The objective of our study was to evaluate the link between the shift in sleep/wake rhythm and the presence of depressive symptoms during the March to May 2020 lockdown in the French population.

PARTICIPANTS AND METHODS

Participants (n = 2513) were recruited via newspapers and social networks in March 2020. We evaluated i) the chronotype before and during the lockdown, assessed by the change in mid-sleep time on work-free days corrected for sleep debt on workdays (delta MSFsc); ii) morningness-eveningness circadian preference (Horne & Ostberg questionnaire); iii) depressive symptoms (Patient Health Questionnaire-9, PHQ-9). The delta MSFsc and the PHQ-9 score were compared between circadian preference types. A multivariate model adjusted for age, sex, circadian preference, housing type, and marital status was used to assess the influence of delta MSFsc on the PHQ-9 score in the whole population.

RESULTS

The population consisted of 77% women, of median (IQR) age 39 (30-48) years. Compared with the pre-lockdown period, the median (IQR) MSFsc was shifted by 30 (0-66) min during the lockdown, with a significant difference between evening [60 (15-120) min], morning [15 (0-46) min] and neutral [30 (0-70) min] circadian type individuals, p < 0.001. One-third of all participants had moderate to severe depressive symptoms (PHQ-9 ≥ 10). A 1-hour shift in MSFsc was associated with a 0.50-point increase [95% CI (0.28; 0.72), p < 0.001] in the PHQ-9.

CONCLUSION

A phase delay in the chronotype was observed in the general population during lockdown. Such disruption was associated with depressive symptoms but the direction of the relationship remains hypothetical. The impact on mental health of preventive measures targeting the sleep/wake rhythm in this context needs further evaluation.

Social Jetlag Is Associated With Impaired Metabolic Control During a 1-Year Follow-Up

Previous studies have identified social jetlag (SJL) as a risk factor for non-communicable chronic diseases (NCCDs), but its association with metabolic control over time is unclear in the literature. Therefore, we examined the influence of SJL on metabolic parameters and blood pressure (BP) in patients with NCCDs over a 1-year follow-up. This retrospective, longitudinal study included 625 individuals (age: 56.0 +12.0 years; 76% female) with NCCDs [type 2 diabetes mellitus (TD2), systemic arterial hypertension (SHA), obesity, or dyslipidemia]. SJL was calculated based on the absolute difference between mid-sleep time on weekends and weekdays. Current metabolic parameters and BP of the patients were compared with data from a year prior. Generalized estimating equations (GEE) and multiple linear regression analyses were used to examine the association among SJL, metabolic parameters, and BP. Multiple linear regression analyses adjusted for confounders showed that SJL was positively associated with the delta difference of fasting glucose (β = 0.11, p = 0.02) and triglyceride levels (β = 0.09, p = 0.04) among all subjects with NCCDs, and with fasting glucose (β = 0.30, p = 0.0001) and triglyceride levels (β = 0.22, p = 0.01) in the TD2 group. GEE analysis demonstrated an isolated effect of SJL on diastolic BP. High SJL impaired clinical and metabolic control in individuals with NCCDs, leading to a worse profile after a 1-year follow-up, particularly among type II diabetics.

Targeting circadian PER2 as therapy in myocardial ischemia and reperfusion injury

The cycle of day and night dominates life on earth. Therefore, almost all living organisms adopted a molecular clock linked to the light-dark cycles. It is now well established that this molecular clock is crucial for human health and wellbeing. Disruption of the molecular clockwork directly results in a myriad of disorders, including cardiovascular diseases. Further, the onset of many cardiovascular diseases such as acute myocardial infarction exhibits a circadian periodicity with worse outcomes in the early morning hours. Based on these observations, the research community became interested in manipulating the molecular clock to treat cardiovascular diseases. In recent years, several exciting discoveries of pharmacological agents or molecular mechanisms targeting the molecular clockwork have paved the way for circadian medicine's arrival in cardiovascular diseases. The current review will outline the most recent circadian therapeutic advances related to the circadian rhythm protein Period2 (PER2) to treat myocardial ischemia and summarize future research in the respective field.

Polysomnography in seasonal affective disorder: A systematic review and meta-analysis

BACKGROUND

. Although sleep disturbances are ubiquitous in depression, studies assessing sleep architecture lead to conflicting results, possibly because of the heterogeneity in this disorder. We aimed to focus on Seasonal Affective Disorder (SAD), which is directly associated with circadian and sleep homeostasis impairments.

METHODS

. A systematic search was conducted in July 2019. Original papers reporting data about night sleep architecture using polysomnography (PSG), in SAD or remitted-SAD and controls, were included.

RESULTS

. Seven studies were retained and included 183 individuals, including 109 patients with SAD and 74 healthy controls. The random-effects meta-analysis showed that rapid eye movement sleep (REM) was significantly increased in SAD compared to controls (REM amount: SMD=1[0.11,1.88], p = 0.027; REM percentage: SMD=0.71[0.02,1.40], p = 0.045). Remitted SAD patients, compared to controls, also had a significantly increased REM sleep (REM amount: SMD=1.84[0.78,2.90], p<0.001; REM percentage: SMD=1.27[0.51,2.03], p = 0.001) and a significantly decreased REM latency (SMD=-0.93[-1.73,-0.13], p = 0.022). No differences were observed for total sleep time, sleep efficiency, and slow-wave-sleep.

LIMITATIONS

. Most studies had small sample size, with no placebo group and with open designs.

CONCLUSIONS

. REM sleep amount and latency appear altered both during the acute and remitted phase of SAD, representing trait markers with interesting diagnosis and therapeutic implications.

Supplemental light exposure improves sleep architecture in people with type 2 diabetes

AIMS

People with type 2 diabetes (T2D) suffer from sleep disorders, with the mechanism not clearly understood. In T2D, the light transducing retinal photoreceptors that regulate sleep behaviours are dysfunctional; hence, we determine here whether supplemental light exposure ameliorates sleep quality and daytime sleepiness in T2D.

METHODS

Supplemental light (10,000 Lux, polychromatic) was self-administered for 30 min every morning for 14 days by ten participants with T2D with no diabetic retinopathy (DR). The effectiveness of supplemental light was assessed by comparing subjective sleep questionnaire (PSQI and ESS) scores and salivary dim light melatonin onset (DLMO) before and after the light exposure as well as with a self-maintained sleep diary during the light exposure.

RESULTS

Compared to the baseline, supplemental light significantly improved the excessive daytime sleepiness score (p = 0.004) and phase-advanced the DLMO on average by ~ 23 min. Sleep diary analyses showed that afternoon nap duration significantly shortened over the first week of supplemental light exposure (p = 0.019). Afternoon naps and midnight awakening were significantly longer in diabetic participants with thinner perifoveal retina.

CONCLUSIONS

In this case series, we provide initial evidence that supplemental bright light improves daytime sleepiness in T2D with no DR, with the critical period of light exposure showing a beneficial effect after one week. We infer that supplemental light augments photoreceptor signalling in T2D and therefore optimises circadian photoentrainment leading to improved sleep. Our findings inform the development of tailored light therapy protocols in future clinical trials for improving sleep architecture in diabetes.

The effects of bright light treatment on affective symptoms in people with dementia: a 24-week cluster randomized controlled trial

BACKGROUND

The majority of people with dementia have behavioral and psychological symptoms of dementia (BPSD), including depression, anxiety and agitation. These may be elicited or aggravated by disrupted circadian rhythms. Bright light treatment (BLT) is a promising non-pharmacological approach to the management of BPSD, but previous research has yielded mixed results.

METHODS

Eight nursing home dementia units (1 unit = 1 cluster) with 78 patients were invited to participate in a cluster randomized controlled trial from September 2017 to April 2018 investigating the effects of BLT on sleep and circadian rhythms (primary outcome) and BPSD (secondary outcome). Ceiling mounted LED-panels were installed in the intervention group (four units), providing light at 1000 lx and 6000 K (vertically at 1.2 m) between 10 a.m. and 3 p.m., with lower values in the mornings and evenings. Standard indoor light was used in the control group (four units). BPSD were assessed with The Cornell Scale for Depression in Dementia (CSDD) and the Neuropsychiatric Inventory Nursing Home Version (NPI-NH). Data collection took place at baseline and after 8, 16 and 24 weeks. Multilevel regression models with and without false discovery rate correction were used for the analysis, with baseline values and dementia stage entered as covariates.

RESULTS

Sixty-nine patients were included in the study at baseline. Compared to the control group, the intervention group had a larger reduction on the composite scores of both the CSDD (95% CI = - 6.0 - - 0.3) and the NPI-NH (95% CI = - 2.2 - - 0.1), as well as on the NPI-NH Affect sub-syndrome, and the CSDD Mood related signs sub-scale at follow-up after 16 weeks. With FDR correction, the group difference was significant on the CSDD Mood related signs sub-scale (95% CI = - 2.7 - - 0.8) and the NPI-NH Affect sub-syndrome (95% CI = - 1.6 - - 0.2). No differences were found between conditions at weeks 8 or 24.

CONCLUSION

Compared to the control condition, affective symptoms were reduced after 16 weeks in the group receiving BLT, suggesting BLT may be beneficial for nursing home patients with dementia.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03357328 . Retrospectively registered on November 29, 2017.

A scoping review of chronotype and temporal patterns of eating of adults: tools used, findings, and future directions

Circadian rhythms, metabolic processes and dietary intake are inextricably linked. Timing of food intake is a modifiable temporal cue for the circadian system and may be influenced by numerous factors, including individual chronotype - an indicator of an individual's circadian rhythm in relation to the light-dark cycle. This scoping review examines temporal patterns of eating across chronotypes and assesses tools that have been used to collect data on temporal patterns of eating and chronotype. A systematic search identified thirty-six studies in which aspects of temporal patterns of eating, including meal timings; meal skipping; energy distribution across the day; meal frequency; time interval between meals, or meals and wake/sleep times; midpoint of food/energy intake; meal regularity; and duration of eating window, were presented in relation to chronotype. Findings indicate that, compared with morning chronotypes, evening chronotypes tend to skip meals more frequently, have later mealtimes, and distribute greater energy intake towards later times of the day. More studies should explore the difference in meal regularity and duration of eating window amongst chronotypes. Currently, tools used in collecting data on chronotype and temporal patterns of eating are varied, limiting the direct comparison of findings between studies. Development of a standardised assessment tool will allow future studies to confidently compare findings to inform the development and assessment of guidelines that provide recommendations on temporal patterns of eating for optimal health.

Temperature rhythms and ICU sleep: the TRIS study

BACKGROUND

Core body temperature (CBT) patterns associated with sleep have not been described in the critically ill. This study aimed to characterize night-time sleep and its relationship to CBT in ICU patients.

METHODS

A prospective study was performed in a 27-bed tertiary adult intensive care unit of 20 mechanically ventilated patients in the weaning stage of their critical illness. The study assessed sleep by polysomnography (PSG) during the evening between 21:00-7:00 hours, nursing interventions using the Therapeutic Intervention Scoring System (TISS), illness severity using SOFA and APACHE II scores and CBT 24-hour pattern.

RESULTS

Patients were awake for approximately half the study period (45.04%, IQR 13.81-77-17) with no REM (0%, IQR 0-0.04%) and median arousals of 19.5/hour (IQR 7.1-40.9). The 24-hour CBT had a rhythmic pattern in 13 (65%) patients with a highly variable phase of median peak time at 17:35 hours (IQR 12:40-19:39). No significant associations were found between CBT rhythmicity, sleep stages, sleep EEG frequency density, illness severity scores or TISS on the day of PSG. There was no relationship between time awake and CBT rhythmicity (P=0.48) or CBT peak time (P=0.82). The relationship between circadian rhythms and sleep patterns in the critically ill is complex.

CONCLUSIONS

Patients recovering in ICU commonly have CBT loss of rhythmicity or a significant phase shift with loss of normal night-time patterns of sleep architecture. Appropriate care plans to promote sleep and circadian rhythm require further investigation of contributing factors such as environment, clinical care routines, illness type and severity.

Intraindividual Variability and Temporal Stability of Mid-Sleep on Free and Workdays

People differ in their sleep timings that are often referred to as a chronotype and can be operationalized as mid-sleep (midpoint between sleep onset and wake-up). The aims of the present studies were to examine intraindividual variability and longer-term temporal stability of mid-sleep on free and workdays, while also considering the effect of age. We used data from a 2-week experience sampling study of British university students (Study 1) and from a panel study of Estonian adults who filled in the Munich Chronotype Questionnaire twice up to 5 years apart (Study 2). Results of Study 1 showed that roughly 50% of the variance in daily mid-sleep scores across the 14-day period was attributed to intraindividual variability as indicated by the intraclass correlation coefficient. However, when the effect of free versus workdays was considered, the intraindividual variability in daily mid-sleep across 2 weeks was 0.71 the size of the interindividual variability. In Study 2, mid-sleep on free and workdays showed good levels of temporal stability-the retest correlations of mid-sleep on free and workdays were 0.66 and 0.58 when measured twice over a period of 0-1 to 5 years. The retest stability of mid-sleep scores on both free and workdays sharply increased from young adulthood and reached their peak when participants were in late 40 to early 50 years of age, indicating that age influences the stability of mid-sleep. Future long-term longitudinal studies are necessary to explore how age-related life circumstances and other possible factors may influence the intraindividual variability and temporal stability of mid-sleep.

"Shedding Light on Light": A Review on the Effects on Mental Health of Exposure to Optical Radiation

In relation to human health and functioning, light, or more specifically optical radiation, plays many roles, beyond allowing vision. These may be summarized as: regulation of circadian rhythms; consequences of direct exposure to the skin; and more indirect effects on well-being and functioning, also related to lifestyle and contact with natural and urban environments. Impact on mental health is relevant for any of these specifications and supports a clinical use of this knowledge for the treatment of psychiatric conditions, such as depression or anxiety, somatic symptom disorder, and others, with reference to light therapy in particular. The scope of this narrative review is to provide a summary of recent findings and evidence on the regulating functions of light on human beings’ biology, with a specific focus on mental health, its prevention and care.

Chronobiology and Chronotherapy in Depression: Current Knowledge and Chronotherapeutic Promises

Background:

Depression is a heavily prevalent mental disorder. Symptoms of depression extend beyond mood, cognition, and behavior to include a spectrum of somatic manifestations in all organic systems. Changes in sleep and neuroendocrine rhythms are especially prominent, and disruptions of circadian rhythms have been closely related to the neurobiology of depression. With the advent of increased research in chronobiology, various pathophysiologic mechanisms have been proposed, including anomalies of sleep architecture, the effects of clock gene polymorphisms in monoamine metabolism, and the deleterious impact of social zeitgebers. The identification of these chronodisruptions has propelled the emergence of several chronotherapeutic strategies, both pharmacological and non-pharmacological, with varying degrees of clinical evidence.

Methods:

The fundamental objective of this review is to integrate current knowledge about the role of chronobiology and depression and to summarize the interventions developed to resynchronize biorhythms both within an individual and with geophysical time.

Results:

We have found that among the non-pharmacological alternatives, triple chronotherapywhich encompasses bright light therapy, sleep deprivation therapy, and consecutive sleep phase advance therapy-has garnered the most considerable scientific interest. On the other hand, agomelatine appears to be the most promising pharmacological option, given its unique melatonergic pharmacodynamics.

Conclusions:

Research in chronotherapy as a treatment for depression is currently booming. Novel interventions could play a significant role in adopting new options for the treatment of depression, with Tripe Cronotherapy standing out as the most promising treatment.

The therapeutic effects and safety of bright light therapy combined with escitalopram oxalate on insomnia in patients with poststroke depression

INTRODUCTION

Bright light therapy (BLT) is known to treat depression and sleep disorders in clinical practice, but its efficacy on poststroke depression (PSD) has not been studied.

OBJECTIVE

To investigate the therapeutic effects and safety of BLT combined with escitalopram oxalate (ESC) on insomnia in patients with PSD.

METHODS

Ischemic stroke patients with depressive symptoms and a score of ≥8 on the Hamilton Depression Scale (HAMD-17) while meeting DSM-IV criteria were diagnosed as having PSD. A total of 112 PSD patients with symptoms of insomnia were randomly assigned to polytherapy (BLT plus ESC) and monotherapy (ESC only) groups. Each regimen continued for 6 weeks. The primary outcomes were a change in scores on the Pittsburgh Sleep Quality Index (PSQI) and a remission rate (PSQI ≤7 at the endpoint). The secondary outcomes included changes in the HAMD-17 and Barthel Index (BI) scores. Adverse effects were assessed by the Adverse Events Scale.

RESULTS

The endpoint assessment included 106 patients (monotherapy, 54; polytherapy, 52). The mean changes in the PSQI scores for the monotherapy and polytherapy groups were 4.85 (1.47) and 5.87 (1.72) (P = 0.001), respectively. Compared to monotherapy, polytherapy improved PSQI remission rate (71.4% vs 50.0%; χ2 = 5.390; P = 0.020), and HAMD-17 score (6.70 [2.12] vs 4.75 [1.98]; P < 0.001). Both treatments improved BI score, with no statistical difference, and were well tolerated, with few significant differences in treatment-associated adverse events.

CONCLUSION

BLT combined with ESC is effective and well tolerated for the treatment of PSD-associated insomnia.

Disrupted circadian rhythms and mental health

During the evolution of life, the temporal rhythm of our rotating planet was internalized in the form of circadian rhythms. Circadian rhythms are ~24h internal manifestations that drive daily patterns of physiology and behavior. These rhythms are entrained (synchronized) to the external environment, primarily by the light-dark cycle, and precisely controlled via molecular clocks located within the suprachiasmatic nucleus of the hypothalamus. Misalignment and/or disruption of circadian rhythms can have detrimental consequences for human health. Indeed, studies suggest strong associations between mental health and circadian rhythms. However, direct interactions between mood regulation and the circadian system are just beginning to be uncovered and appreciated. This chapter examines the relationship between disruption of circadian rhythms and mental health. The primary focus will be outlining the association between circadian disruption, in the form of night shift work, exposure to light at night, jet lag, and social jet lag, and psychiatric illness (i.e., anxiety, major depressive disorder, bipolar disorder, and schizophrenia). Additionally, we review animal models of disrupted circadian rhythms, which provide further evidence in support of a strong association between circadian disruption and affective responses. Finally, we discuss future directions for the field and suggest areas of study that require further investigation.

Detecting Critical Decision Points during Cognitive-Behavioral Therapy and Light Therapy for Winter Depression Nonremission and Recurrence

Using data from a clinical trial comparing cognitive-behavioral therapy (CBT-SAD) and light therapy (LT) for winter seasonal affective disorder (SAD; N = 177), we explored critical decision points, or treatment weeks, that predict likelihood of nonremission at post-treatment and depression recurrence following treatment. In receiver operator characteristic (ROC) curve analyses, we used weekly Structured Clinical Interview for the Hamilton Rating Scale for Depression-SAD Version (SIGH-SAD) scores during treatment to predict nonremission at post-treatment (Week 6) and recurrence one winter later (Winter 1), two winters later (Winter 2), and any recurrence. Although several C-statistics of ≥ .70 were found, only Week 4 SIGH-SAD scores in CBT-SAD for nonremission had enough predictive ability to inform clinical decision-making (C-statistic = .80; sensitivity = .91; specificity = .68). Week 4 of CBT-SAD may be a critical time point to identify likely nonremitters who need tailoring of intervention, based on SIGH-SAD cutpoint score ≥ 13. This study illustrates how clinical trial data can inform detecting optimal decision points in treatment for identifying patients unlikely to remit, a critical first step to developing adaptive treatment strategies using decision rules to operationalize when and for whom treatment should change to maximize clinical benefit.

Sex differences in subjective age-associated changes in sleep: a prospective elderly cohort study

Subjective age-associated changes in sleep (AACS) and sex differences in AACS have never been prospectively investigated in elderly populations. We compared the AACS every 2 years over a total of 6 years between 4,686 community-dwelling healthy men and women aged 60 years or older who participated in the Korean Longitudinal Study on Cognitive Aging and Dementia. Sleep parameters including sleep duration, latency, and efficiency, mid-sleep time, daytime dysfunction, and overall subjective sleep quality were measured using the Pittsburgh Sleep Quality Index at baseline and at each follow-up. The effects of time and sex on subjective sleep parameters were analyzed using linear mixed-effects models. During the 6 years of follow-up, we observed that overall, sleep latency increased, while daytime dysfunction and sleep quality worsened. Significant sex differences in AACS was found, with women showing shortened sleep duration, delayed mid-sleep time, and decreased sleep efficiency over 6 years. Sleep quality worsened in both groups but a more pronounced change was observed in women. Clinicians should be cautious in determining when to treat declared sleep disturbances in this population.

Changes of white matter microstructure after successful treatment of bipolar depression

BACKGROUND

Diffusion tensor imaging (DTI) measures suggest a widespread alteration of white matter (WM) microstructure in patients with bipolar disorder (BD). The chronotherapeutic combination of repeated total sleep deprivation and morning light therapy (TSD+LT) can acutely reverse depressive symptoms in approximately 60% of patients, and it has been confirmed as a model antidepressant treatment to investigate the neurobiological correlates of rapid antidepressant response.

METHODS

We tested if changes in DTI measures of WM microstructure could parallel antidepressant response in a sample of 44 patients with a major depressive episode in course of BD, treated with chronoterapeutics for one week. We used both a tract-wise and a voxel-wise approach for the whole-brain extraction of DTI measures of WM microstructure: axial (AD), radial (RD), and mean diffusivity (MD), and fractional anisotropy (FA).

RESULTS

Compared to baseline level, at one-week follow up we observed a significant increase in average FA measures paralleled by a significant decrease in MD measures of several WM tracts including cingulum, corpus callosum, corona radiata, cortico-spinal tract, internal capsule, fornix and uncinate fasciculus. The degree of change was associated to clinical response.

CONCLUSIONS

This is the first study to show changes of individual DTI measures of WM microstructure in response to antidepressant treatment in BD. Our results add new evidence to warrant a role for chronotherapeutics as a first-line treatment for bipolar depression and contribute identifying generalizable neuroimaging-based biomarkers of antidepressant response.

Integrating wearable data into circadian models

The emergence of wearable health sensors in the last decade has the potential to revolutionize the study of sleep and circadian rhythms. In particular, recent progress has been made in the use of mathematical models in the prediction of a patient's internal circadian state using data measured by wearable devices. This is a vital step in our ability to identify optimal circadian timing for health interventions. We review the available data for fitting circadian phase models with a focus on wearable data sets. Finally, we review the current modeling paradigms and explore avenues for developing personalized parameter sets in limit cycle oscillator models in order to further improve prediction accuracy.

Circadian Misalignment Is Negatively Associated with the Anthropometric, Metabolic and Food Intake Outcomes of Bariatric Patients 6 Months After Surgery

PURPOSE

Circadian misalignment has been associated with an increased risk of overweight and obesity, as well as changes in metabolic parameters. This study evaluated the association between social jet lag (SJL), a measure of circadian misalignment, and anthropometric, metabolic and food intake outcomes 6 months after bariatric surgery.

MATERIALS AND METHODS

A total of 122 bariatric patients were included (77% female, aged 33 years (range 28-41); 79.5% underwent Roux-en-Y gastric bypass). Anthropometric, food consumption and SJL were evaluated in the preoperative evaluation and in the third and sixth months after surgery. SJL was calculated based on the absolute difference between the mid-sleep time on weekends and weekdays. Generalised estimating equations and linear regression were performed to evaluate the associations between mean SJL exposure and the outcomes.

RESULTS

The interaction between SJL and follow-up time negatively influenced the evolution of weight (p = 0.01), BMI (p = 0.04) and insulin levels (p = 0.01). SJL had an effect on intake of calories (p = 0.001), carbohydrate (p = 0.005) and total (p = 0.007), monounsaturated (p = 0.03) and polyunsaturated fat (p < 0.001). Linear regression showed a negative association between mean SJL exposure over the 6 months and the percentage of weight loss (coefficient = - 0.30, p = 0.006), body weight loss (kg) (coefficient = - 0.17, p = 0.03) and the reduction of BMI (coefficient = - 0.24, p = 0.007).

CONCLUSIONS

SJL was negatively associated with anthropometric, metabolic and food consumption outcomes 6 months after bariatric surgery. Future studies with longer follow-up are needed to confirm these findings.

TRIAL REGISTRATION

Clinical Trials.gov : NCT03485352.

Applying experimental therapeutics to examine cognitive and chronological vulnerabilities as mediators of acute outcomes in cognitive-behavioral therapy and light therapy for winter depression

OBJECTIVE

We applied the experimental therapeutics approach to test whether acute treatment outcomes for winter seasonal affective disorder (SAD) are mediated by a cognitive mechanism in cognitive-behavioral therapy (CBT-SAD) versus a chronobiologic mechanism in light therapy (LT).

METHOD

Currently depressed adults with major depression, recurrent with seasonal pattern (N = 177; 83.6% female, 92.1% non-Hispanic White, M age = 45.6) were randomized to 6 weeks of LT or group CBT-SAD. SAD symptoms were assessed weekly on the Structured Clinical Interview for the Hamilton Rating Scale for Depression-SAD Version. At pre-, mid-, and posttreatment, participants completed measures of general depressogenic cognitions (Dysfunctional Attitudes Scale; DAS); SAD-specific negative cognitions (Seasonal Beliefs Questionnaire; SBQ); chronotype (Morningness-Eveningness Questionnaire; MEQ); and depressive symptoms (Beck Depression Inventory-Second Edition).

RESULTS

Parallel-process growth models showed evidence for hypothesized mechanisms. For SAD-specific negative cognitions (SBQ), both symptom measures showed (1) an effect of treatment group on the slope of the mediator, with CBT-SAD demonstrating greater decreases, and (2) an effect of the slope of the mediator on the slope of the outcome. These effects held for the SBQ but not the broader measure of depressogenic cognitions (DAS). For the chronotype measure (MEQ), treatment assignment affected change, whereby LT was associated with reduced "eveningness," but this was unrelated to change in symptoms.

CONCLUSIONS

CBT-SAD promoted decreases in SAD-specific negative cognitions, and these changes were related to decreases in symptoms. Consistent with the theory that LT corrects misaligned circadian rhythms, LT reduced eveningness, but this did not correspond to symptom improvement. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Validation of the Portuguese Variant of the Munich Chronotype Questionnaire (MCTQPT)

Introduction

Differences in the manner circadian clocks entrain to the 24-h day are expressions of different chronotypes that can range from extreme early to extreme late, from proverbial larks to owls. The Morningness Eveningness Questionnaire (MEQ) was one of the first to assess daily preference based on subjective self-assessment – a psychological construct. The later developed Munich Chronotype Questionnaire (MCTQ) uses instead the actual sleep timing to assess chronotype. It calculates the mid-sleep point, halfway between onset and offset on work-free days (MSF), which is then corrected for potential oversleep on free days compensating for sleep debt accumulated over the workweek (MSF_sc). MSF_sc is expressed in local time and is thought to be a proxy for “phase of entrainment” of the circadian clock. The MCTQ-derived chronotype is therefore a biological construct. In the present report, we validate the Portuguese variant (MCTQ^PT) of the MCTQ. Portugal is of particular interest, since it is thought to consist of especially late chronotypes.

Methods

We have used three methods to assess the timing of daily behavior, namely, the chronotype (MCTQ), the daily preference (rMEQ), and a simple self-assessment (time-of-day type). A total of 80 healthy adults living in Portugal, with age and sex distributed according to the Portuguese population, were recruited. We analyzed 4 weeks of continuous records of actimetry data to validate the MCTQ^PT and used the rMEQ to compare between a biological chronotype (sleep timing) and a psychological chronotype (daily preference). MCTQ variables were analyzed by descriptive statistics; correspondence between measurements was done by Spearman correlations or cross-tabulation; in a subset of 41 individuals, test–retest reliability was assessed.

Results

MCTQ-derived variables (MSF, MSW, MSF_sc) correlated highly with their counterparts calculated from actimetry (MSW: rho = 0.697; MSF: rho = 0.747; MSF_sc: rho = 0.646; all p < 0.001). The MCTQ assessment of the chronotype showed good test–retest reliability (rho = 0.905; p < 0.001). The rMEQ score correlates with MSF_sc (rho = −0.695; p < 0.001), and the agreement for the self-assessment with the MSF_sc was fair (kw = 0.386; p < 0.001).

Conclusion

The Portuguese variant of the MCTQ revealed to be a reliable questionnaire to assess the chronotype for the Portuguese adult population, as previously reported for other countries.

Cognitive Vulnerabilities as Prognostic Predictors of Acute and Follow-up Outcomes in Seasonal Affective Disorder Treatment with Light Therapy or Cognitive-Behavioral Therapy

BACKGROUND

First-line treatments for winter seasonal affective disorder include light therapy and cognitive-behavioral therapy; however, it is unclear whether particular patient profiles respond differentially to each treatment type. This study examined baseline patient cognitive and chronobiological vulnerabilities as prognostic and prescriptive predictors of acute and follow-up treatment outcomes.

METHODS

177 adults with seasonal affective disorder were randomized to 6-weeks of either light therapy or cognitive-behavioral therapy. Participants completed baseline measures of cognitive vulnerabilities (Dysfunctional Attitudes Scale; Ruminative Response Scale; Seasonal Belief Questionnaire) and chronobiological vulnerability (Morningness-Eveningness Questionnaire). Depression was assessed at pre- and post-treatment and at follow-ups one and two winters later.

RESULTS

Pre-treatment depression severity correlated significantly with each cognitive vulnerability measure, and significantly predicted future depression. After controlling for pre-treatment depression, higher scores on the Morningness-Eveningness Questionnaire were prognostic of lower depression at treatment endpoint, but no cognitive vulnerability emerged as a prognostic or prescriptive predictor of outcome.

CONCLUSIONS

Greater morningness was associated with less severe post-treatment depression in both cognitive-behavior therapy and light therapy. No cognitive vulnerability emerged as a prognostic or prescriptive predictor, perhaps because they correlated with pre-treatment depression severity, a robust predictor of outcome. Future research should test alternative cognitive constructs.

Chronotype in very low birth weight adults - a sibling study

Chronotype is the temporal preference for activity and sleep during the 24 h day and is linked to mental and physical health, quality of life, and mortality. Later chronotypes, so-called "night owls", consistently display poorer health outcomes than "larks". Previous studies have suggested that preterm birth (<37 weeks of gestation) is associated with an earlier chronotype in children, adolescents, and young adults, but studies beyond this age are absent. Our aim was to determine if adults born preterm at very low birth weight (VLBW, ≤1500 g) display different chronotypes than their siblings. We studied VLBW adults, aged 29.9 years (SD 2.8), matched with same-sex term-born siblings as controls. A total of 123 participants, consisting of 53 sibling pairs and 17 unmatched participants, provided actigraphy-derived data on the timing, duration, and quality of sleep from 1640 nights (mean 13.3 per participant, SD 2.7). Mixed effects models provided estimates and significance tests. Compared to their siblings, VLBW adults displayed 27 min earlier sleep midpoint during free days (95% CI: 3 to 51 min, p =.029). This was also reflected in the timing of falling asleep, waking up, and sleep-debt corrected sleep midpoint. The findings were emphasized in VLBW participants born small for gestational age. VLBW adults displayed an earlier chronotype than their siblings still at age 30, which suggests that the earlier chronotype is an enduring individual trait not explained by shared family factors. This preference could provide protection from risks associated with preterm birth.

ABBREVIATIONS

AGA: Appropriate for gestational age; ELBW: Extremely low birth weight, ≤ 1000 grams; FMBR: Finnish Medical Birth Registry; HeSVA: Helsinki Study of Very low birth weight Adults; MSFsc: Midsleep on free days, corrected for sleep debt; SGA: Small for gestational age, ≤ -2 SD; VLBW: Very low birth weight, ≤ 1500 grams; WASO: Wake after sleep onset.

The Energy Saving Potential of Wide Windows in Hospital Patient Rooms, Optimizing the Type of Glazing and Lighting Control Strategy under Different Climatic Conditions

If not properly designed, the adoption of large windows can sometimes have a negative impact on building energy demand. For this reason, aggravated by the outdated building envelope of the healthcare building stock, large fenestration systems are usually avoided in hospitals, especially in old structures. However, with appropriate glazing specifications, the adoption of wider openings can result into significant energy savings, lower costs and strong positive effects on patients and staff well-being. The present study investigates how different window sizes and types of glazing affect heating, cooling and lighting energy demand in a hospital patient room. The objective is to evaluate the energy savings that may be obtained when installing larger windows and to identify the glazing properties allowing one to reach the maximum energy reductions. Simulations were carried out using nine diverse glazing systems, already available on the market, and their energy performance was evaluated in relation to two different window areas: a common size opening, characterized by a 25% Window-to-Wall Ratio (WWR), and a floor to ceiling window, with 77% WWR. The analysis was conducted taking into consideration four different orientations in four Italian cities, supposing two artificial lighting control strategies. The results highlighted how the adoption of wider windows with appropriate glazings and a daylight-linked dimming lighting control strategy may lower the primary energy demand up to 17%.

Carbon monoxide: a critical physiological regulator sensitive to light

The mechanism by which humans absorb therapeutic light in winter seasonal and nonseasonal depression is unknown. Bright-light-induced release and generation of blood-borne gasotransmitters such as carbon monoxide (CO) may be one mechanism. Here, 24 healthy female volunteers had peripheral blood samples drawn. Samples were collected in a dimly lit room and protected from light exposure. Samples were analyzed for CO concentrations by gas chromatography after 2 h of continuous exposure to darkness vs. bright white light. In a similar confirmatory study, 11 additional volunteers had samples analyzed for CO concentrations after 2 h of continuous exposure to gentle rocking in darkness vs. in bright white light. In the first study, light-unexposed peripheral blood had a mean CO concentration of 1.8 ± 0.4 SD ppm/g. Identically treated samples with 2 h of rocking and exposure to bright white light at illuminance 10,000 lux had a mean CO of 3.6 ± 1.2 ppm/g (p < 0.0001). Post hoc analysis of that study showed that time of day was significantly inversely associated with increase in CO concentration under bright light vs. dark (p < 0.04). In a smaller confirmatory study of 11 healthy female volunteers, after 2 h of rocking, light-unexposed peripheral blood had a mean CO of 1.4 ± 0.5 SD ppm/g. Identically treated blood samples with 2 h of exposure to bright white light at illuminance 10,000 lux had a mean CO of 2.8 ± 1.7 ppm/g (p < 0.02). In conclusion, bright-light exposure robustly increases human blood CO in vitro. This supports the putative role of CO as a physiological regulator of circadian rhythms and light's antidepressant effects. This human evidence replicates earlier data from a preclinical in vivo model. This effect may be stronger in the morning than in the afternoon.

The Elapsed Time between Dinner and the Midpoint of Sleep is Associated with Adiposity in Young Women

Meal timing relative to sleep/wake schedules is relevant in the search for obesity risk factors. However, clock time does not accurately characterize the timing of food intake in the context of internal circadian timing. Therefore, we studied elapsed between dinner and the midpoint of sleep (TDM) as a practical approach to evaluate meal timing relative to internal timing, and its implications on obesity. To do so, adiposity, sleep, diet, physical activity, and TDM were measured in 133 women. The participants were grouped into four categories according to their sleep timing behavior (early-bed/early-rise; early-bed/late-rise; late-bed/early-rise; late-bed/late-rise). Differences among the categories were tested using ANOVA, while restricted cubic splines were calculated to study the association between TDM and adiposity. Our results show that, although participants had dinner at about the same time, those that had the shortest TDM (early-bed/early-rise group) were found to have significantly higher BMI and waist circumference values (2.3 kg/m² and 5.2 cm) than the other groups. In addition, a TDM of 6 h was associated with the lowest values of adiposity. The TDM could be a practical approach to personalizing meal timing based on individual sleep/wake schedules. Thus, according to our findings, dining 6 h before the midpoint of sleep is an important finding and could be vital for future nutritional recommendations and for obesity prevention and treatment.