Sex differences in the association between chronotype and risk of depression

Perceived stress and academic achievement among medical students with different chronotypes: a cross sectional study on first year medical students from India

BACKGROUND

Chronotype, which denotes an individual's preference for morning or evening activity patterns, has been linked to variations in cognitive performance, sleep behavior, and stress levels. This study investigates the association between chronotype, perceived stress, and academic performance among first-year medical students.

METHODS

A cross-sectional descriptive study was conducted among 148 medical students at a private university. Chronotype was assessed using the Munich Chronotype Questionnaire (MCTQ), and perceived stress was measured using the Perceived Stress Scale (PSS). Academic performance was categorized into "Excellent" (marks > 65%) and "Average" (marks < 55%). Statistical analyses included independent t-tests, chi-square tests to evaluate differences and associations.

RESULTS

Morning chronotypes demonstrated significantly higher academic performance, with 49.1% in the "Excellent" group compared to 29% of Evening chronotypes (p =.03). Perceived stress scores were significantly higher among Evening chronotypes (24.9 ± 12.1) than Morning chronotypes (20.7 ± 9.3, p =.028). Furthermore, Evening chronotypes exhibited longer sleep latency (41.17 ± 13.35 min vs. 14.49 ± 12.14 min, p <.001) and greater variability in weekend sleep schedules (p <.001). Gender differences in stress and academic performance were minimal and not statistically significant.

CONCLUSION

Chronotype significantly affects academic performance and stress levels among medical students, with Morning types performing better academically experiencing less stress. Tailored strategies like flexible scheduling and sleep hygiene promotion can help Evening chronotypes overcome challenges, improving academic outcomes and psychological well-being.

Mindfulness mediates the association between chronotype and depressive symptoms in young adults

BACKGROUND

Chronotype influences risk of depression, with evening-types at higher risk, although the reasons for this are uncertain. Potential mediating factors include mindfulness, sleep quality, rumination, and alcohol consumption, but research is lacking.

METHODS

We explored the role of these factors in the association between chronotype and depressive symptoms amongst young adults, using cross-sectional data collected from a university student sample (N =  546).

RESULTS

Evening-types had significantly higher levels of depression symptoms, poorer sleep quality, and lower levels of 'acting with awareness' and 'describing', as well as higher rumination and alcohol consumption. Mediation analyses demonstrated that the link between chronotype and depression was fully mediated by 'acting with awareness', 'describing', sleep quality, and alcohol consumption.

LIMITATIONS

Only subjective measures were employed, and due to the cross-sectional design, no causal inferences can be made.

CONCLUSION

The mediation results shed light on the crucial role of specific mindfulness facets, sleep, and alcohol consumption for explaining why evening types are at higher risk of depression; findings have import for potential interventions aiming to reduce depression risk amongst young adults in particular.

The relationship between chronotype and treatment time of day on post-treatment depression symptom severity for depressed patients receiving cognitive behavioural therapy

BACKGROUND

Major depressive disorder (MDD) represents a serious public health problem that affects a quarter billion individuals worldwide. Consequently, there is a need to identify modifiable factors of services that support treatment success. The relationship between circadian preferences (i.e., chronotype), treatment time of day, and outcomes is an understudied research area. Executing optimal treatment timing based on these factors could lead to substantial returns on a modifiable variable.

METHOD

The present study evaluated the associations between chronotype and treatment time of day on post-treatment depression symptom severity. In a tertiary setting, outpatients with MDD (n = 227) received 14 sessions of cognitive behavioural therapy in a group format, at one of three time of days: morning, afternoon, or evening. Participants completed measures of depression and chronotype at baseline and post-treatment.

RESULT

Statistically significant increases in morningness were found for the afternoon and evening groups, but not the morning group. There was no significant interaction effect between pre-treatment morningness-eveningness scores and treatment time of day on post-treatment depression scores nor treatment response. However, there was a significant interaction effect of change in morningness-eveningness scores and post-treatment depression severity in the afternoon group.

LIMITATIONS

The lack of a control group limits conclusions drawn.

CONCLUSION

The results suggest that individual circadian phase may impact treatment outcomes in relation to time of day. Further intentionally designed research is warranted to improve understanding of predictors, moderators, and mediators of patient outcomes based on treatment time of day and circadian phase and amplitude.

Depression and Accelerated Aging: The Eveningness Chronotype and Low Adherence to the Mediterranean Diet Are Associated with Depressive Symptoms in Older Subjects

BACKGROUND AND OBJECTIVES

Depression often results in premature aging, which increases the risk of other chronic diseases, but very few studies have analyzed the association between epigenetic biomarkers of aging and depressive symptoms. Similarly, limited research has examined the joint effects of adherence to the Mediterranean diet (MedDiet) and chronotype on depressive symptoms, accounting for sex differences. Therefore, these are the objectives of our investigation in a Mediterranean population at high cardiovascular risk.

METHODS

We analyzed 465 older subjects (aged 55-75) with metabolic syndrome and assessed depressive symptoms by the Beck Depression Inventory (BDI-II). MedDiet adherence was measured with the 17-item MedDiet score, and chronotype with the Morningness-Eveningness Questionnaire (MEQ). Blood DNA methylation was analyzed, and epigenomic biomarkers of age acceleration were determined. We focused on the Dunedin Pace of Aging Computed from the Epigenome (DunedinPACE). We fitted multivariable models with interaction terms.

RESULTS

Prevalence of depression was statistically higher in women (p < 0.001). MedDiet adherence was strongly and inversely associated with depressive symptoms in the whole population (p < 0.01), while the MEQ score was inversely associated (p < 0.05). In the joint analysis, both MedDiet adherence and chronotype remained statistically associated with the BDI-II score (p < 0.05), showing additive effects. No interaction effects were observed. In women, a higher score in depressive symptoms was significantly associated with faster age acceleration (measured with the DunedinPACE biomarker). This association remained significant even after adjustment for MedDiet adherence and chronotype.

CONCLUSIONS

In older subjects with metabolic syndrome, the eveningness chronotype was associated with greater depressive symptoms, but a higher adherence to the MedDiet could potentially counteract the chronotype risk with additive effects. Women showed stronger associations, and importantly, we reported for the first time in this population that depressive symptoms were associated with accelerated aging.

Circadian rhythms and objective measures of physical activity among middle-aged and older adults in Taiwan

BACKGROUND

To identify the association between daytime activity with objectively monitor and subjective variables at a different time-zone of day as well as the sex differences.

METHODS

Participants aged 50 years and older living in the community in Taiwan were recruited. The activity was measured by wearable actigraphy devices, diaries, and self-reported questionnaires. The study used nonparametric analysis to examine the association between mean activity level and demographic and subjective measurement variables.

RESULTS

Among the 55 participants enrolled in the study, data of 34 (62 %) participants who meet the criteria that wore a wearable actigraphy device for at least 7 completed days were analyzed. There is no significant relationship between each demographics and subjective measurement variables. However, actigraphy counts are significantly related to female's nutrition (Z = -2.367, p = 0.017*), and male's retirement status (Z = -2.132, p = 0.033*).

CONCLUSIONS

The activity in morning is highest of the day with significant correlation to evening activities. Moreover, actigraphy counts that indicating objective measure of physical activity in female is significantly related to physiological variables (nutritional status), while male are predicted by social variables (retired status).

Analyzing the effect of sleep duration, chronotype, and social jet lag on anxiety disorders and health-related quality of life: A cross-sectional study

BACKGROUND

Anxiety disorders significantly impair the quality of life (QOL). Studies on the effect of sleep duration, chronotype, and social jet lag on anxiety disorders are limited. This study aimed to elucidate the contributions of sleep duration, chronotype, and social jet lag to the prevalence and severity of anxiety disorders in Koreans.

METHODS

This study used data of 9,874 Korean adults from the Korea National Health and Nutrition Examination Survey 2021-2022. Anxiety was assessed using the Generalized Anxiety Disorder-7 scale, and health-related QOL was measured using the Health-Related Quality of Life Instrument with 8-Items. Complex sample logistic regression models were used to evaluate the associations between sleep duration, chronotype, and social jet lag and anxiety disorders, with analyses stratified by sex.

RESULTS

Sleep duration of <6 h, evening chronotype, and social jet lag of >2 h were significantly associated with a high prevalence of anxiety disorders in women; however, in men, only sleep duration of <6 h was associated with anxiety disorders. Sleep duration of <6 h and evening chronotype were associated with low QOL in women but not in men.

CONCLUSION

This study highlights the importance of adequate sleep and circadian alignment for mental health, particularly in women. Public health initiatives should focus on promoting healthy sleep habits to improve mental health and QOL. Further research is required to understand the causal pathways and sex-specific mechanisms underlying these associations.

Nonlinear and symptom specific associations between chronotype and depression

The chronotype of individuals has been found to be predictive of depression risk and associated with the severity of depression. However, since depression is a phenotypically heterogeneous disease, it seems improbable that chronotype plays a role in every instance of depression. This study investigates the association between the two, while considering possible symptom-specificity and non-linearity of the relationship, utilizing a large sample from the National Health and Nutrition Examination Survey (N = 5217; 54% female; Age: M = 52.65, SD = 18.76). Depression symptoms were assessed using the Patient Health Questionnaire-9 (PHQ-9), and chronotype was determined by calculating sleep midpoints. Further, we also explored the potential mediating role of systemic inflammation, measured by C-reactive protein (CRP) levels, in the chronotype-depression link. The findings substantiate previous research indicating late chronotypes to be associated with higher PHQ-9 sum scores, with a minimum in PHQ-9 at a sleep midpoint of 02:49. The study further differentiates between individual depression symptoms, uncovering varying patterns of association with chronotype. No significant effect of chronotype on levels of CRP was found, suggesting that the link between chronotype and depression symptoms may not be directly mediated and appears to be stable and independent from systemic inflammation. The study highlights the non-linear and symptom-specific nature of the chronotype-depression connection and suggests the need for further, longitudinal studies to elucidate causal mechanisms and potential mediators.

Relationship Between BMI, Self-Rated Depression, and Food Addiction-A Cross-Sectional Study of Adults in Postpandemic Poland

Depression and obesity are two diseases that have a profound impact on global health. The relationship between obesity and depression is strongly comorbid, tending to exacerbate metabolic and depressive symptoms. Research also shows that there are complex interactions between obesity, depression symptoms, and food addiction (FA). The aim of the study was to investigate the relationship between body mass index (BMI), self-rated depression, and FA. The study sample consisted of 735 subjects (90.2% female, M BMI = 27.58 kg/m2, standard deviation (SD)BMI = 6.58 kg/m2) aged 18-70 years (M = 39.01, SD = 14.07). The prevalence of FA symptoms was measured using the Yale Food Addiction Scale 2.0 and self-rated depression was assessed using the Zung Self-Rating Depression Scale. The prevalence of FA in the group was 41% and self-rated depression was present in 34.1% of the participants. It was found that the higher the BMI of the subjects, the higher the severity of FA, but the BMI was not significantly correlated with the severity of depression. In addition, the greater the severity of self-rated depression, the greater the severity of FA. This correlation was stronger for men than for women in the 18-30 and 31-45 age groups. The severity of self-rated depression and FA was significantly higher in people with an eating disorders. This study adds to the growing body of evidence suggesting that the presence and severity of FA are associated with the severity of self-rated depression, particularly in younger adults. In addition, people with a high BMI, indicating obesity, are more likely to have FA, especially severe FA.

Moderating effects of PER3 gene DNA methylation on the association between problematic mobile phone use and chronotype among Chinese young adults: Focus on gender differences

Objective

To investigate the rates of problematic mobile phone use (PMPU) and chronotypes in young adults, and examine the associations of PMPU with chronotypes, as well as its gender differences. Furthermore, we explored the moderating role of PER3 gene DNA methylation on the associations.

Methods

From April to May 2019, a total of 1,179 young adults were selected from 2 universities in Anhui and Jiangxi provinces. The Self-rating Questionnaire for Adolescent Problematic Mobile Phone Use (SQAPMPU) and reduced Morningness-Eveningness Questionnaire (rMEQ) were adopted to investigate PMPU and chronotypes in young adults, respectively. Moreover, 744 blood samples were collected to measure PER3 gene DNA methylation. Multivariate logistic regression models were established to analyze the associations between PMPU and chronotypes. Moderating analysis was used to determine whether PER3 gene DNA methylation moderated the relationships between PMPU and chronotypes.

Results

The prevalence of PMPU, morning chronotypes (M-types), neutral chronotypes (N-types), and evening chronotypes (E-types) of young adults were 24.6%, 18.4%, 71.1%, and 10.5%, respectively. Multivariate logistic regression results indicated that PMPU was positively correlated with E-types (OR = 3.53, 95%CI: 2.08-6.00), and the association was observed only in females after stratified by gender (OR = 5.36, 95%CI: 2.70-10.67). Furthermore, PER3 gene DNA methylation has a negative moderating role between PMPU and chronotypes and has a sex-based difference.

Conclusions

This study can provide valuable information for the prevention and control of circadian rhythm disturbance among young adults from the perspective of epidemiology and biological etiology.

Prospective study of the association between chronotypes and depressive symptoms in Chinese university students: Moderating effects of PER1 gene DNA methylation

Most studies have shown a link between chronotypes and mental health and have identified evening chronotypes (E-types) as a potential risk for depressive symptoms. However, the mechanisms behind this association remain unknown. Abnormal expression of the PER1 gene was not only associated with circadian rhythm disturbance, but also closely related to mental illness. Therefore, this study aimed to examine the association of chronotype with depressive symptoms, and further explore the moderating effects of the PER1 gene DNA methylation on chronotypes and depressive symptoms in Chinese university students. In a stratified cluster sampling design, chronotype and depressive symptoms were assessed in 1 042 university students from 2 universities in a two-year prospective survey from April 2019 to October 2020. The survey was conducted once every 6 months, corresponding to the time points in April 2019 (T0), October 2019 (T1), April 2020 (T2), and October 2020 (T3). At T0, the Morning and Evening Questionnaire 5 (MEQ-5) was adopted to assess chronotype. At T0-T3, the Patient Health Questionnaire 9 (PHQ-9) was adopted to investigate depressive symptoms. Meanwhile, at T0, participants were subjected to a health check-up trip in the hospital, and blood samples were taken from the students to measure the PER1 gene DNA methylation levels. Binary logistic regression was used to analyze the association of chronotypes with depressive symptoms. The depression/total depression group was coded as 1, while the remaining participants was defined as one group, and was coded as 0. The PROCESS plug-in of SPSS software was used to analyze the moderating effects of PER1 gene DNA methylation on the association of chronotype with depressive symptoms. After adjusting for covariates, the results indicated that T0 E-types were positively correlated with T0-T3 depression/total depression in female university students. Furthermore, the PER1 gene DNA methylation has negative moderating effects between T0 chronotype and T3 depressive symptoms and has a sex difference. This study can provide more favorable scientific value for the prevention and control of depression in university students.

Associations of chronotype with anxiety, depression and insomnia among general adult population: A cross-sectional study in Hubei, China

BACKGROUND

The relationship between chronotype and anxiety, depression, and insomnia was inconsistent. We aimed to assess the association between chronotype and mental health and the potential moderating effect of age and socioeconomic status (SES).

METHODS

A multi-stage sampling cross-sectional study with 12,544 adults was conducted. Chronotype, anxiety, depression, and insomnia were investigated by 5-item Morning and Evening, 7-item Generalized Anxiety Disorder, 9-item Patient Health, and the 7-item Insomnia Severity Index Questionnaires. Logistic regression was conducted.

RESULTS

The predominant chronotype was morning chronotype (69.2 %), followed by 27.6 % intermediate and 3.2 % evening chronotype. The prevalence of anxiety, depression, and insomnia was 0.7 %, 1.9 %, and 9.6 %, respectively. Compared with intermediate chronotype, morning chronotype participants had a lower risk of anxiety (OR = 0.28,95%CI:0.18-0.44), depression (OR = 0.54,95%CI:0.41-0.72) and insomnia (OR = 0.67,95%CI:0.58-0.77), while evening chronotype participants had a higher risk of depression (OR = 1.98,95%CI:1.06-3.71) but not anxiety or insomnia. Interactions between chronotype with age and SES on insomnia (Pinteraction < 0.05) were found. A more profound association between morning chronotype and insomnia was observed in <65 years participants (OR = 0.59,95%CI:0.50-0.71) and those with monthly household income ≥10,000yuan (OR = 0.21,95%CI:0.12-0.35), compared with their counterparts.

LIMITATIONS

The cross-sectional design limited causal conclusions. Only adults were included; the findings could not be generalized to children.

CONCLUSIONS

The morning chronotype might be protective for anxiety, depression, and insomnia, while the evening chronotype might be a risk factor for depression. Future studies are needed to assess the efficacy of chronotype-focused intervention for mental health. Insomnia prevention efforts should pay more attention to the elderly and those with lower incomes.

The role of social support in the relation between chronotype and mental health in a cohort of women from the American Heart Association Go Red for Women Strategically Focused Research Network

Women are disproportionally affected by psychological distress and lack of social support and are more vulnerable to the negative impact of chronotype on mental health. This study evaluates cross-sectional associations between chronotype and mental health, while assessing the mediating role of social support among women from diverse racial/ethnic backgrounds. Women from the American Heart Association Go Red for Women Research Network were included (N = 506, mean age = 37 ± 15.7, 61% racial/ethnic minority). Chronotype, depression, perceived stress, health-related quality of life, and social support were assessed at baseline using validated self-reported questionnaires. Linear regression and causal mediation analyses were performed. Depression and negative emotionality were higher among women with evening vs. morning/intermediate chronotypes (all p < 0.05). Multivariable analyses adjusted for sociodemographic and clinical confounders showed associations between evening chronotype and higher depression (p = 0.004) and negative emotionality (p = 0.010). However, these associations were no longer significant after adjusting for social support (depression: p = 0.12; negative emotionality: p = 0.18). Social support significantly mediated 44.6% and 45.8% of the total effect of chronotype on depression and negative emotionality, respectively. Social support represents a potential mechanism underlying the associations between eveningness and poor mental health. Chronotype and social support should be considered in interventions for the promotion of mental health in women.

Timing and duration of dog walking and dog owner's chronotype in relation to incident depression risk among middle to older-aged female nurses

BACKGROUND

We examined associations between dog ownership, morning dog walking and its timing and duration, and depression risk in female nurses, exploring effect modification by chronotype. We hypothesized that dog ownership and morning walking with the dog are associated with lower odds of depression, and that the latter is particularly beneficial for evening chronotypes by helping them to synchronize their biological clock with the solar system.

METHODS

26,169 depression-free US women aged 53-72 from the Nurses' Health Study 2 (NHS2) were prospectively followed from 2017-2019. We used age- and multivariable-adjusted logistic regression models to estimate odds ratios (ORs) and 95% confidence intervals (95%CIs) for depression according to dog ownership, and morning dog walking, duration, and timing.

RESULTS

Overall, there was no association between owning a dog (ORvs_no_pets = 1.12, 95%CI = 0.91-1.37), morning dog walking (ORvs_not = 0.87, 95%CI = 0.64-1.18), or the duration (OR>30min vs. ≤15mins = 0.68, 95%CI = 0.35-1.29) or timing of morning dog walks (ORafter9am vs. before7am = 1.06, 95%CI = 0.54-2.05) and depression. Chronotype of dog owners appeared to modify these associations. Compared to women of the same chronotype but without pets, dog owners with evening chronotypes had a significantly increased odds of depression (OR = 1.60, 95%CI = 1.12-2.29), whereas morning chronotypes did not (OR = 0.94, 95%CI = 0.71-1.23). Further, our data suggested that evening chronotypes benefited more from walking their dog themselves in the morning (OR = 0.75, 95%CI = 0.46-1.23, Pintx = 0.064;) than morning chronotypes.

CONCLUSIONS

Overall, dog ownership was not associated with depression risk though it was increased among evening chronotypes. Walking their dog in the morning might help evening chronotypes to lower their odds of depression, though more data are needed to confirm this finding.

Mapping insomnia symptoms and circadian preferences to mental health problems in men and women across the lifespan

This study identified subgroups in the general population based on combinations in three night-time insomnia symptoms and four dimensions of circadian preferences ("sleep profiles") and investigated the associations between sleep profiles and nine common mental health problems. The data came from the Lifelines cohort add-on study "Comorbid Conditions of ADHD" and included 37,716 individuals (aged 4-91 years) from the Dutch general population who completed a digital survey. Latent profile analysis was used to identify sleep profiles in twelve age-sex subgroups. Linear regression was used to investigate whether sleep profiles differ in mental health problems. Participants were classified into three sleep profiles: "Healthy Larks", who had early circadian preferences and no insomnia symptoms; "Sleepy Owls" with late circadian preferences and nonrestorative sleep; and "Sleepless Doves" with intermediate circadian preferences and severe insomnia symptoms. Compared to "Healthy Larks", all mental health problems were significantly more severe in "Sleepy Owls" and even worse in "Sleepless Doves". These associations were similar in men and women but weakened with age. However, "Sleepy Owls" and "Sleepless Doves" did not differ in heavy alcohol drinking, drug use, and smoking. Our findings strengthened the evidence for the universal role of healthy sleep in mental wellbeing.

Associations between weekend catch-up sleep and health-related quality of life with focusing on gender differences

This study investigated associations between weekend catch-up sleep (WCUS) and health-related quality of life (HRQoL) in 15,837 participants from the 7th (2016-2018) Korea National Health and Nutrition Examination Survey. We categorized WCUS durations into four groups: none (≤ 0 h [h]), short (> 0 h, ≤ 1 h), medium (> 1 h, ≤ 2 h), and long (> 2 h), and performed complex samples logistic regression and likelihood ratio χ2 test. The study found significant associations in women for the European Quality of Life-5 Dimensions (EQ-5D) index and three EQ-5D subdomains (self-care, usual activities, and anxiety/depression) with the WCUS durations, but no significant association in men. Compared to the non-WCUS, the short or medium WCUS was positively associated with the EQ-5D index and EQ-5D subdomains (usual activities and anxiety/depression) in women, while the long WCUS significantly reduced the quality of life in the self-care domain. In an additional subgroup analysis by age, middle-aged and elderly women had a more noticeable effect of WCUS on HRQoL than young women, and the short or medium WCUS improved HRQoL in middle-aged and elderly women in general. Therefore, we recommend appropriate WCUS durations to improve HRQoL, considering both gender and age.

Mediation analysis of chronotype, sleep-related factors, and depressive symptoms among workers: a cross-sectional study

Background

This study aimed to examine the impact of chronotype on depressive symptoms and explore the mediating effects of sleep quality, pre-sleep cognitive arousal, and social jetlag in a sample of wage earners.

Methods

A total of 3,917 waged workers were surveyed online in July 2022. Logistic regression and mediation analysis were used to assess the relationship between chronotype (morningness, intermediate, and eveningness) and depressive symptoms (Patient Health Questionnaire ≥ 5), and the mediating effects of Insomnia Severity Index (ISI), Pittsburgh Sleep Quality Index (PSQI), and Pre-Sleep Arousal Scale (PSAS). All analyses were adjusted for age, education level, income level, marital status, coffee consumption, alcohol consumption, physical activity, occupation, employment status, and working hours to calculate odds ratios (ORs).

Results

The chronotypes of all the participants were divided into morningness (4.7%), intermediate (93.5%), and eveningness (1.8%). Multiple logistic regression analysis showed an increased risk of depression in the eveningness chronotype (OR: 2.96; 95% confidence interval [CI]: 1.51, 5.86). Regarding the mediation analysis, ISI mediated 28.44% (95% CI: 16.39-40.5), PSQI for 31.25% (95% CI: 19.36, 43.15), and PSAS-Cognitive Score (PSAS-C) for 23.58% (95% CI: 10.66, 36.50) of the association between chronotype and depressive symptoms. However, social jetlag did not significantly mediate this relationship. (percentage mediated = 0.75%, 95% CI: -3.88, 5.39).

Conclusions

Evening chronotypes exhibit an increased risk of depressive symptoms, which ISI, PSQI, and PSAS-C partially mediated. This suggests that interventions to improve sleep quality and maintain adequate sleep habits may effectively prevent and treat depression in employees with an eveningness chronotype.

Investigating Chronotype and Sleep Quality in Psoriatic Patients: Results from an Observational, Web-Based Survey

BACKGROUND

Psoriasis is an inflammatory disease for which the implications and repercussions go far beyond the skin. Psoriasis patients suffer not only due to its skin manifestations and related symptoms but also because of comorbidities and a huge emotional impact.

OBJECTIVE

The objective of this study was to investigate chronotype and sleep quality in a group of Italian psoriatic patients.

MATERIALS AND METHODS

An observational, cross-sectional, web-based study was set up by the Dermatology and Clinical Medicine Sections of the Department of Medical Sciences, University of Ferrara, Italy. The web questionnaire was sent to an email list of an Italian association of psoriatic patients with the aim of recording their main demographic, social, historical, and clinical data. The survey included two questionnaires: the Morningness-Eveningness Questionnaire (MEQ) and the Pittsburg Sleep Quality Index (PSQI).

RESULTS

Two hundred and forty-three psoriatic patients (mean age 52.9 ± 12.8 yrs., 32.5% males and 67.5% females) filled out the questionnaire. A good 63.8% of them were affected with psoriasis for more than 10 years, 25.9% reported having a diffuse psoriasis, and 66.7% were on treatment at the time they completed the questionnaire. With reference to chronotype, the mean MEQ score was 55.2 ± 10.7; furthermore, 44% of the patients were "morning-oriented types", M-types, or "larks", 44.5% were "intermediate-types" or I-types, and 11.5% were "evening-oriented types", E-types, or "owls". No correlations were found between chronotype and psoriasis extension. Based on the PSQI results, 72.8% of the study population was judged to have a low sleep quality. Sleep disturbance was significantly related to female sex, living alone, and the presence of comorbidities.

CONCLUSIONS

Sleep disturbance is very common in psoriatic patients, especially in those with comorbidities, in females, and in patients who live alone. The chronotype in psoriatic patients does not appear different when compared to the general population, nor does it seem to have any link with psoriasis severity.

Health Professionals' Chronotype Association with Salivary Cortisol and Occupational Stress in Neonatal Intensive Care Units

Burnout syndrome has been reported among health workers, particularly those working in critical areas, and is considered a significant public health problem. This study aimed to investigate the relationship between chronotype and work-related stress, as measured by salivary cortisol levels and burnout, among health professionals working in neonatal intensive care units. A cross-sectional study was conducted across four public hospitals in Fortaleza, Ceará, Brazil. Two hundred and fifty-six health professionals were administered the brazilian version of the Burnout Characterization Scale, the morningness-eveningness questionnaire, for chronotype, a sociodemographic questionnaire that included lifestyle habits and a salivary cortisol test. The results indicated that morning chronotype workers were significantly associated with the following: advanced age (p < 0.001), female gender (p = 0.032), married status (p = 0.014), and having children (p = 0.030) compared to those with evening and intermediate chronotypes. However, no significant association was found between signs of burnout syndrome and chronotype (p = 0.316). Participants whose work shift did not match their chronotype had significantly higher initial salivary cortisol levels (p = 0.013). The findings suggest that adapting working hours to an individual's biological rhythm can help mitigate potential negative effects on physical and mental health. Thus, it is recommended that professionals' working hours be adjusted accordingly.

Beyond sleep: A multidimensional model of chronotype

Chronotype can be defined as an expression or proxy for circadian rhythms of varied mechanisms, for example in body temperature, cortisol secretion, cognitive functions, eating and sleeping patterns. It is influenced by a range of internal (e.g., genetics) and external factors (e.g., light exposure), and has implications for health and well-being. Here, we present a critical review and synthesis of existing models of chronotype. Our observations reveal that most existing models and, as a consequence, associated measures of chronotype have focused solely or primarily on the sleep dimension, and typically have not incorporated social and environmental influences on chronotype. We propose a multidimensional model of chronotype, integrating individual (biological and psychological), environmental and social factors that appear to interact to determine an individual's true chronotype with potential feedback loops between these factors. This model could be beneficial not only from a basic science perspective but also in the context of understanding health and clinical implications of certain chronotypes as well as designing preventive and therapeutic approaches for related illnesses.

Effect of sleep and fatigue on cardiovascular performance in young, healthy subjects

Physical performance could be negatively affected by sleep deficiency and fatigue. The present study assesses the role of sleep quality, fatigue and motivation on cardiovascular performance (VO₂peak, Wmax, and HRmax) in a sample of active young subjects. The current study is a cross-sectional design. Ninety-six university students (males 54.2%; 21.5 ± 2.9 yrs) completed an incremental exercise test on a bicycle ergometer. Sleep, fatigue, and motivation were assessed with the Pittsburgh Sleep Quality Index and two visual analogue scales, respectively. Differences in VO₂peak, Wmax, HRmax, self-perceived fatigue and motivation were compared between good and bad sleepers and sleep duration >/<7.5 h, while regression analysis defined the predictors of VO₂peak, Wmax, and HRmax_. In the male sample, good and bad sleepers' differences were significant only for self-perceived fatigue (p = 0.04). The female sample showed no statistically significant differences between good and bad sleepers and different sleep durations. In the male sample, linear regression analysis showed a significant inverse correlation between Wmax and the PSQI score (-0.4, p = 0.004). The stepwise regression model indicated that sleep (β = -0.3, p = 0.02) was a significant predictor of VO₂peak in males accounting for 20% of the variance, whereas physical performance seems more affected by fatigue (β = -0.4, p = 0.03) in females. In conclusion, chronic inadequate and self-reported sleep quality seems to be one of the factors compromising cardiovascular performance in males.

Chronotype, circadian rhythm, and psychiatric disorders: Recent evidence and potential mechanisms

The circadian rhythm is crucial for physiological and behavioral functions. Chronotype, which represents individual preferences for activity and performance, is associated with human health issues, particularly psychiatric disorders. This narrative review, which focuses on the relationship between chronotype and mental disorders, provides an insight into the potential mechanism. Recent evidence indicates that (1) the evening chronotype is a risk factor for depressive disorders and substance use disorders, whereas the morning chronotype is a protective factor. (2) Evening chronotype individuals with bipolar disorder tend to have more severe symptoms and comorbidities. (3) The evening chronotype is only related to anxiety symptoms. (4) The relationship between chronotype and schizophrenia remains unclear, despite increasing evidence on their link. (5) The evening chronotype is significantly associated with eating disorders, with the majority of studies have focused on binge eating disorders. Furthermore, the underlying mechanisms or influence factors are described in detail, including clock genes, brain characteristics, neuroendocrinology, the light/dark cycle, social factors, psychological factors, and sleep disorders. These findings provide the latest evidence on chronotypes and psychiatric disorders and serve as a valuable reference for researchers.

Chronotype Profile, Stress, Depression Level, and Temporomandibular Symptoms in Students with Type D Personality

Background: Despite a growing interest in the types of human circadian activity, different chronotypes and personality-related issues have been rarely studied. It has already been emphasized that ‘stress personality’ is considered a risk factor for certain psychosomatic diseases and may be a temporomandibular disorders (TMDs) predictor. Therefore, an attempt has been made to analyze the chronotypes, stress levels, stress factors, and the occurrence of depression and TMDs in students with type D personalities. People with this personality trait tend to experience negative emotions more—depression, anxiety, anger, or hostility—yet may have a negative image of themselves and report somatic complaints. Aim: The aim of this study was to analyze the importance of the chronotype profile for the level of stress perceived, as well as for the occurrence of depression and TMDs in people with type D personalities. Material and Methods: The study has been conducted on a group of 220 physical therapy students. The study group G1 consisted of 110 participants with type D personalities, the control group G2 consisted of the same number of participants without the stress personality. All participants have been analyzed for the chronotype (MEQ), stress perception (PSS10), the occurrence of depression (Beck scale-BDI), the occurrence of TMDs symptoms and have completed the stress factor assessment questionnaire during the study, followed by DS14 questionnaire—a tool for assessing the prevalence of type D personality. Results: In students with type D personalities (G1), the definitely evening and evening chronotypes have been significantly more predominant than in the control group (G2). A significantly higher number of stressors and TMDs symptoms have been observed in the respondents from the G1 group than in the control group (<0.001). Univariate logistic regression analysis showed that type D personality was strongly associated with a more frequent occurrence of all TMD symptoms. Additionally, a significant influence of the evening chronotype on the occurrence of type D personality was observed. Among the potential confounding variables, female gender and a mild and moderate degree of depression have an impact on the occurrence of type D personality (p < 0.05). In the multivariate model, adjusted with the above-mentioned factors, an increased risk of the type D personality trait was found. Conclusion: The evening chronotype and type D personality may imply greater feelings of stress, greater depression, and more frequent symptoms of TMDs in young adults.

Sex differences in the relationship between morningness-eveningness components, mood and well-being among Bangladeshi university students

On the Morningness/Eveningness (M/E) continuum, eveningness has been related to mood disorder and poor well-being. M/E differs between men and women throughout their lifespan. However, there is a lack of information on sex differences in the relationship between M/E, mood, and well-being. This study aimed to test sex differences in the M/E, mood, and well-being relationship with consideration of two components of M/E, morning affect, and morning preference. A sample of 981 Bangladeshi university students (607 men) aged 18 to 27 (M = 21.95) completed Bangla versions of the Composite Scale of Morningness (CSM), BRUnel Mood Scale (BRUMS), and Positive Mental Health scale (PMH-scale) through an online survey. Multiple regression analyses were used to test the relationship of M/E components with mood and well-being. The results showed that the relationship between M/E, mood, and well-being was greater in women than in men. A lower score on both M/E components was related to higher negative moods (anger, confusion, depression, fatigue, and tension) and poor well-being. In regression analysis, only morning affect was found to be significant, which means that morning affect mainly contributes to the relation between M/E, mood, and well-being. Finally, sex by morning affect interaction indicated that the relation was higher for women. Therefore, higher eveningness could be more hazardous for women than men. Greater insight into the independent contribution of morning affect may facilitate understanding of the chronotype effects on psychological outcomes in men and women.

Chrono-communication and cardiometabolic health: The intrinsic relationship and therapeutic nutritional promises

Circadian rhythm, an innate 24-h biological clock, regulates several mammalian physiological activities anticipating daily environmental variations and optimizing available energetic resources. The circadian machinery is a complex neuronal and endocrinological network primarily organized into a central clock, suprachiasmatic nucleus (SCN), and peripheral clocks. Several small molecules generate daily circadian fluctuations ensuring inter-organ communication and coordination between external stimuli, i.e., light, food, and exercise, and body metabolism. As an orchestra, this complex network can be out of tone. Circadian disruption is often associated with obesity development and, above all, with diabetes and cardiovascular disease onset. Moreover, accumulating data highlight a bidirectional relationship between circadian misalignment and cardiometabolic disease severity. Food intake abnormalities, especially timing and composition of meal, are crucial cause of circadian disruption, but evidence from preclinical and clinical studies has shown that food could represent a unique therapeutic approach to promote circadian resynchronization. In this review, we briefly summarize the structure of circadian system and discuss the role playing by different molecules [from leptin to ghrelin, incretins, fibroblast growth factor 21 (FGF-21), growth differentiation factor 15 (GDF15)] to guarantee circadian homeostasis. Based on the recent data, we discuss the innovative nutritional interventions aimed at circadian re-synchronization and, consequently, improvement of cardiometabolic health.

Diurnal preference and depressive symptomatology: a meta-analysis

Eveningness, a preference for later sleep and rise times, has been associated with a number of negative outcomes in terms of both physical and mental health. A large body of evidence links eveningness to Major Depressive Disorder (MDD). However, to date, evidence quantifying this association is limited. The current meta-analysis included 43 effect sizes from a total 27,996 participants. Using a random-effects model it was demonstrated that eveningness is associated with a small effect size (Fisher's Z = - 2.4, 95% CI [- 0.27. - 0.21], p < 0.001). Substantial heterogeneity between studies was observed, with meta-regression analyses demonstrating a significant effect of mean age on the association between diurnal preference and depression. There was also evidence of potential publication bias as assessed by visual inspection of funnel plots and Egger's test. The association between diurnal preference and depression is small in magnitude and heterogenous. A better understanding of the mechanistic underpinnings linking diurnal preference to depression and suitably powered prospective studies that allow causal inference are required.

Chronotype and social support among student athletes: impact on depressive symptoms

Previous studies have shown individuals with evening chronotype to have a greater likelihood for depression (self-reported and clinical ratings), especially in young adults. However, the mechanisms for this relationship remain unknown. Low levels of social support may be a plausible mechanism: young adults with evening chronotypes are awake when others are sleeping, which may lead to feelings of isolation or low support. This study examined links between chronotype, depression, and social support in relationship subtypes within a group of university student athletes. Data were obtained from 189 NCAA Division-I student athletes across all sports. Chronotype was assessed with the Circadian Energy Scale and ranged from -2 (definitely morning type) to +2 (definitely evening type). Depressive symptoms were assessed with Center for Epidemiological Studies Depression scale. Social support was assessed with the Multidimensional Scale of Perceived Social Support, which included subscales for Family, Friends, and Significant Other. A subscale for Team was created using the items from the Friends subscale (changing the word "friends" to "teammates"). Regression analyses adjusted for age, sex, and minority status. More evening chronotype was associated with higher reported depressive symptoms (p = .018), lower overall perceived social support (p = .001), and lower perceived social support specifically provided by family (p < .0001), friends (p < .0001), and teammates (p = .014). However, more evening chronotype was associated with higher depressive symptoms for higher, but not lower perceived social support from significant other. Moreover, chronotype-by-support interactions on depressive symptoms were observed; the statistical relationship between chronotype and depression was evident only in those with low (but not high) social support from friends and teammates. These data suggest that having a more evening chronotype may be associated with social isolation, and decreased opportunities for interactions with friends and teammates. This may contribute to the long-standing circadian association seen with depression in college student-athletes. Interventions aimed at increasing university support networks may reduce the impact of depression in students self-identifying with later chronotypes and sleep schedules.

Biological Rhythm and Chronotype: New Perspectives in Health

The circadian rhythm plays a fundamental role in regulating biological functions, including sleep–wake preference, body temperature, hormonal secretion, food intake, and cognitive and physical performance. Alterations in circadian rhythm can lead to chronic disease and impaired sleep. The circadian rhythmicity in human beings is represented by a complex phenotype. Indeed, over a 24-h period, a person’s preferred time to be more active or to sleep can be expressed in the concept of morningness–eveningness. Three chronotypes are distinguished: Morning, Neither, and Evening-types. Interindividual differences in chronotypes need to be considered to reduce the negative effects of circadian disruptions on health. In the present review, we examine the bi-directional influences of the rest–activity circadian rhythm and sleep–wake cycle in chronic pathologies and disorders. We analyze the concept and the main characteristics of the three chronotypes.

The effect of subjective sleep latency on BMI of medical interns during and before COVID-19 pandemic

OBJECTIVES

Longer subjective sleep latency and eveningness chronotype are associated with higher BMI. Moreover, COVID-19 lockdown changes have been associated with increased BMI. The aim of this study was to investigate the effect of subjective sleep parameters on BMI of medical interns during and before COVID-19 pandemic.

MATERIAL AND METHODS

This cross-sectional study was performed among medical interns. Bedtime, sleep latency, waking time, sleep duration, and reduced morningness-eveningness scores were evaluated.

RESULTS

There was significant difference between bedtime before (00:11±50) and during (01:10±85) the pandemic in females (p<0.001). The mean circadian score before and during the pandemic showed significant decrease in females (p=0.011). The correlation between BMI with subjective sleep latency in females before and during the pandemic ((r=0.439, p=0.017), (r=0.422, p=0.014)) was significant.

CONCLUSION

COVID-19 pandemic was associated with a change toward nocturnal life among female medical interns. Subjective sleep latency was significantly correlated with BMI in females.