Age and Sex Differences in Morningness/Eveningness Along the Life Span: A Cross-Sectional Study in Spain

Sleep Characteristics in Dance Students Related to Psychological Inflexibility

Introduction: Dance, as a performance activity, is associated with various problems. Among these challenges, sleep disturbances are notably prevalent. Aims: This study aimed to explore the potential relationship between sleep characteristics-specifically chronotype and subjective sleep quality- and psychological inflexibility in dance students. Methods: This research adopted a cross-sectional design using non-probabilistic sampling. The data were collected in paper format by visiting public conservatories and private academies, and online. One hundred fourteen dance students, with a mean age of 23.87 years, participated in the study. Assessment tools included the Acceptance and Action Questionnaire-II, Pittsburgh Sleep Quality Index, and the Composite Scale of Morningness. Results: The results revealed that 80.7% of all students reported poor sleep quality, compared to 19.3% who reported good sleep quality. Differences emerged in both subjective sleep quality (F(2, 113) = 4.825, P = .010) and chronotype (F(2, 113) = 6.172, P = .003) when students were grouped according to low, medium, or high levels of psychological inflexibility. Those with low inflexibility, as opposed to those with high inflexibility, report better sleep quality, with no differences observed between medium and high inflexibility groups. Students with high-medium levels of psychological inflexibility showed a higher risk (OR = 6.373 times higher) of experiencing poor sleep quality compared to those with low psychological inflexibility. In terms of chronotype, the low inflexibility group is inclined to be more of a morning type than the medium and high inflexibility groups, with no differences between the latter 2 groups. Students categorized as having low inflexibility tend to have a longer history of dancing under the guidance of a teacher and dedicate more hours and days per week to rehearsal. Conclusion: Conservatories can become "healthy spaces." In this regard, sleep hygiene programs and Acceptance and Commitment Therapy interventions can provide guidance to professionals working with dancers in professional companies and conservatories.

Association between sleep hours and changes in cognitive function according to the morningness-eveningness type: A population-based study

OBJECTIVE

The aim of this study was to investigate proper sleep hours to reduce the risk of cognitive decrease considering morningness-eveningness type.

METHODS

The Korean Community Health Survey was used, which includes adults aged over 19 years old. These data were obtained from a cross-sectional study and assessed sleep hours using questionnaire of Pittsburgh Sleep Quality Index. Based on the wake-up time of each participant, they were classified into the morningness, intermediate, eveningness, and none groups. The change in cognitive function was determined by a single question about memory loss experience.

RESULTS

A total of 224,714 participants were included in the analysis. Of the participants, 55.6 % and 5.0 % of whom had morningness and eveningness, respectively. The risk of cognitive decline was significantly different by sleep hours and morningness-eveningness type. Without considering sleep quality, the intermediate and eveningness groups showed a higher risk of cognitive decline than the morningness group, and the risk was lowest in those with 7-9 sleep hours. However, when sleep quality showing significant effect was included in the analysis, sleep hours showing the lowest risk were different among morningness, intermediate, eveningness groups, and it was the shortest in the morningness type at 5-6 h and the longest in the eveningness type at 7-8 h.

CONCLUSION

Proper sleep hours to decrease the risk of cognitive decline may be different by morningness-eveningness types. However, when considering sleep quality, sleep duration had little influence on cognitive decline. Future studies investigating healthy sleep hours need to consider sleep quality as well as the habitual sleep schedules.

LIMITATIONS

The morningness-eveningness types were classified based on wake-up time not morningness-eveningness types. The morningness-eveningness types in this study would be interpreted as habitual sleep schedule rather than chronotype.

For Whom (and When) the Time Bell Tolls: Chronotypes and the Synchrony Effect

Circadian rhythms are powerful timekeepers that drive physiological and intellectual functioning throughout the day. These rhythms vary across individuals, with morning chronotypes rising and peaking early in the day and evening chronotypes showing a later rise in arousal, with peaks in the afternoon or evening. Chronotype also varies with age from childhood to adolescence to old age. As a result of these differences, the time of day at which people are best at attending, learning, solving analytical problems, making complex decisions, and even behaving ethically varies. Across studies of attention and memory and a range of allied areas, including academic achievement, judgment and decision-making, and neuropsychological assessment, optimal outcomes are found when performance times align with peaks in circadian arousal, a finding known as the synchrony effect. The benefits of performing in synchrony with one's chronotype (and the costs of not doing so) are most robust for individuals with strong morning or evening chronotypes and for tasks that require effortful, analytical processing or the suppression of distracting information. Failure to take the synchrony effect into consideration may be a factor in issues ranging from replication difficulties to school timing to assessing intellectual disabilities and apparent cognitive decline in aging.

The Interactive Role of Sleep and Circadian Rhythms in Episodic Memory in Older Adults

Adequate sleep is essential for healthy physical, emotional, and cognitive functioning, including memory. However, sleep ability worsens with increasing age. Older adults on average have shorter sleep durations and more disrupted sleep compared with younger adults. Age-related sleep changes are thought to contribute to age-related deficits in episodic memory. Nonetheless, the nature of the relationship between sleep and episodic memory deficits in older adults is still unclear. Further complicating this relationship are age-related changes in circadian rhythms such as the shift in chronotype toward morningness and decreased circadian stability, which may influence memory abilities as well. Most sleep and cognitive aging studies do not account for circadian factors, making it unclear whether age-related and sleep-related episodic memory deficits are partly driven by interactions with circadian rhythms. This review will focus on age-related changes in sleep and circadian rhythms and evidence that these factors interact to affect episodic memory, specifically encoding and retrieval. Open questions, methodological considerations, and clinical implications for diagnosis and monitoring of age-related memory impairments are discussed.

Evidence for environment hypothesis: Cross-cultural measurement invariance of the composite scale of morningness across Bangladesh and Spain

Morningness-eveningness reflects individual differences in circadian functioning and is related to health and well-being. Cross-cultural comparison could facilitate understanding of the environmental factors affecting morningness-eveningness, which requires establishing cross-cultural validity of the relevant assessment tools. In this study, we applied the Composite Scale of Morningness (CSM) to Bangladeshi (n = 1015; 37.9% women) and Spanish (n = 1054; 73.2% women) university students (aged 18-27 years) to evaluate alternative factorial models of the CSM and to test its measurement invariance across cultures. Moreover, this study tested environment hypothesis, suggesting that higher average temperatures and lower latitudes would be related to greater morningness. From nine competing factorial models, a bifactor model with two specific factors (morning preference and morning affect) showed the best fit for both cultures. The two-factor bifactor model had full metric invariance with partial scalar and strict invariance across cultures. The Bangladesh-Spain comparison of the CSM scores revealed higher morningness in Bangladeshi students which supports the environment hypothesis. Overall, this research confirms that morningness-eveningness construct is perceived and interpreted similarly by the Bangladeshi and Spanish students. Importantly, this study highlights the effects of environmental factors including latitude and temperature on morningness-eveningness, and thus facilitates further cross-cultural morningness-eveningness research.

Cross-sectional interrelationships between chronotype, obstructive sleep apnea and blood pressure in a middle-aged community cohort

Chronotype is linked to adverse health measures and may have important associations with obstructive sleep apnea and blood pressure, but data are limited. This study aimed to determine the separate and combined associations of chronotype with obstructive sleep apnea and blood pressure in a middle-aged community population. Adults (n = 811) from the Raine Study (female = 59.2%; age mean [range] = 56.6 [42.1-76.6] years) were assessed for chronotype (Morningness-Eveningness Questionnaire), blood pressure and hypertension (doctor diagnosed or systolic blood pressure ≥ 140 mmHg and/or diastolic ≥ 90 mmHg), and obstructive sleep apnea at different in-laboratory apnea-hypopnea index thresholds (5, 10, 15 events per hr). Linear and logistic regression models examined relationships between chronotype and the presence and severity of obstructive sleep apnea, blood pressure, hypertension, and blood pressure stratified by obstructive sleep apnea severity at above-mentioned apnea-hypopnea index thresholds. Covariates included age, sex, body mass index, alcohol consumption, smoking, physical activity, sleep duration, anti-hypertensive medication, insomnia, and depressive symptoms. Most participants were categorised as morning (40%) or intermediate (43%), with 17% meeting criteria for evening chronotypes. Participants with apnea-hypopnea index ≥ 15 events per hr and morning chronotype had higher systolic (9.9 mmHg, p < 0.001) and a trend for higher diastolic blood pressure (3.4 mmHg, p = 0.07) compared with those with an evening chronotype, and higher systolic blood pressure compared with those with an intermediate chronotype (4.8 mmHg, p = 0.03). Across chronotype categories, no differences in systolic or diastolic blood pressure or odds of hypertension were found at apnea-hypopnea index thresholds of ≥ 5 or ≥ 10 events per hr. Among participants with apnea-hypopnea index ≥ 15 events per hr, systolic blood pressure is higher in those with a morning chronotype than evening and intermediate chronotypes. Assessment for morning chronotype may improve risk stratification for hypertension in patients with obstructive sleep apnea.

Morning affect or sleep inertia? Comparing the constructs and their measurement

The construct of Morning Affect (MA; alertness upon awakening/time required to feel fully awake) emerged from exploratory factor analysis of morningness-eveningness questionnaires, and while it has been equated with morningness-eveningness preference it has much conceptual overlap with sleep inertia (SI; the transitional state between sleep and being fully awake). The current study compared questionnaire measures of these constructs to help clarify their inter-relationships. A volunteer sample of 453 students at an English-medium university in China completed an online survey including the Sleep Inertia Questionnaire (SIQ), the Morningness-Eveningness-Stability-Scale-improved (MESSi), with subscales for MA, Eveningness, and Distinctness (amplitude of diurnal variation), and the reduced Morningness-Eveningness Questionnaire (rMEQ). Measures of depression, sleep quality, mindfulness, and personality were also included. Exploratory factor analysis of the SIQ, MESSi, and rMEQ items revealed seven factors: Cognitive, Emotional, and Physiological SI, Responses to SI (including one MA item), and Duration of SI (one SIQ item, 3/5 MA items, and one rMEQ item); Morningness-Eveningness (MESSi Eveningness items, plus 3/5 rMEQ items); Distinctness (3/5 MESSi items). These results suggest that Morning Affect may be better characterised as a general measure of sleep inertia, and may contribute to ongoing development/refinement of questionnaire measures of circadian functioning.

The circadian preferences in the context of sociodemographic indicators and lifestyle

Circadian preferences are frequently used as a synonym for chronotype. Both terms are based on different principles and are measured by a variant questionnaire. We focused on circadian preferences, delimited as an individual preference for the timing of various activities, and their relationship to the selected sociodemographic factors. All participants (n = 2068) filled out online questionnaires including MEQ, MCTQ, and sociodemographic information (age, sex, place of residence, marital status, childcare, education, financial security, physical and mental health). Although the concept of chronotype and circadian preference differ, the mutual correlation was high. Our results of the observed variables are similar to other studies. We revealed evening preference is related to a higher probability of living in a big city, having a single life, a higher risk of smoking, worse health status, and worse financial security. We observed a higher social jet lag among them. Our research complies with previous studies, which found that in some areas, people with evening preferences evince worse results. Due to the evening preference, these people are at a disadvantage, and the society's setting for morning operations can lead to a deepening of these differences. We recommend further research, which would focus on the practical application of results to the everyday life of participants to create preventive programs aimed at reducing the negative impact of evening preferences on life.

Bifactor exploratory structural equation modeling: A meta-analytic review of model fit

Multivariate behavioral research often focuses on latent constructs-such as motivation, self-concept, or wellbeing-that cannot be directly observed. Typically, these latent constructs are measured with items in standardized instruments. To test the factorial structure and multidimensionality of latent constructs in educational and psychological research, Morin et al. (2016a) proposed bifactor exploratory structural equation modeling (B-ESEM). This meta-analytic review (158 studies, k = 308, N = 778,624) aimed to estimate the extent to which B-ESEM model fit differs from other model representations, including confirmatory factor analysis (CFA), exploratory structural equation modeling (ESEM), hierarchical CFA, hierarchical ESEM, and bifactor-CFA. The study domains included learning and instruction, motivation and emotion, self and identity, depression and wellbeing, and interpersonal relations. The meta-analyzed fit indices were the χ2 /df ratio, the comparative fit index (CFI), the Tucker-Lewis index (TLI), the root mean square error of approximation (RMSEA), and the standardized root mean squared residual (SRMR). The findings of this meta-analytic review indicate that the B-ESEM model fit is superior to the fit of reference models. Furthermore, the results suggest that model fit is sensitive to sample size, item number, and the number of specific and general factors in a model.

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.

Demographic characteristics associated with circadian rest-activity rhythm patterns: a cross-sectional study

BACKGROUND

Rest-activity rhythm (RAR), a manifestation of circadian rhythms, has been associated with morbidity and mortality risk. However, RAR patterns in the general population and specifically the role of demographic characteristics in RAR pattern have not been comprehensively assessed. Therefore, we aimed to describe RAR patterns among non-institutionalized US adults and age, sex, and race/ethnicity variation using accelerometry data from a nationally representative population.

METHODS

This cross-sectional study was conducted using the US National Health and Nutrition Examination Survey (NHANES) 2011-2014. Participants aged ≥20 years who were enrolled in the physical activity monitoring examination and had at least four 24-h periods of valid wrist accelerometer data were included in the present analysis. 24-h RAR metrics were generated using both extended cosinor model (amplitude, mesor, acrophase and pseudo-F statistic) and nonparametric methods (interdaily stability [IS] and intradaily variability [IV]). Multivariable linear regression was used to assess the association between RAR and age, sex, and race/ethnicity.

RESULTS

Eight thousand two hundred participants (mean [SE] age, 49.1 [0.5] years) were included, of whom 52.2% were women and 67.3% Whites. Women had higher RAR amplitude and mesor, and also more robust (pseudo-F statistic), more stable (higher IS) and less fragmented (lower IV) RAR (all P trend < 0.001) than men. Compared with younger adults (20-39 years), older adults (≥ 60 years) exhibited reduced RAR amplitude and mesor, but more stable and less fragmented RAR, and also reached their peak activity earlier (advanced acrophase) (all P trend < 0.001). Relative to other racial/ethnic groups, Hispanics had the highest amplitude and mesor level, and most stable (highest IS) and least fragmented (lowest IV) RAR pattern (P trend < 0.001). Conversely, non-Hispanic blacks had the lowest peak activity level (lowest amplitude) and least stable (lowest IS) RAR pattern (all P trend < 0.001).

CONCLUSIONS

In the general adult population, RAR patterns vary significantly according to sex, age and race/ethnicity. These results may reflect demographic-dependent differences in intrinsic circadian rhythms and may have important implications for understanding racial, ethnic, sex and other disparities in morbidity and mortality risk.

The role of sleep hygiene in the risk of Shift Work Disorder in nurses

A high proportion (20%-30%) of shift workers experience Shift Work Disorder (SWD), characterized by chronic sleepiness and/or insomnia associated with work schedules. The reasons for individual variation in shift work tolerance are not well understood, however. The aim of this study was to identify individual factors that contribute to the risk of SWD. Nurses (n = 202) were categorized as low or high risk of SWD based on the Shift Work Disorder Questionnaire. Participants provided demographic and lifestyle information and completed the Sleep Hygiene Index (SHI) and Morningness-Eveningness Questionnaire (MEQ). High risk of SWD was associated with poorer sleep hygiene (SHI, 35.41 ± 6.19 vs. 31.49 ± 7.08, p < .0001) and greater eveningness (MEQ, 34.73 ± 6.13 vs. 37.49 ± 6.45, p = .005) compared to low risk. No other factors, including body mass index, marital status, having children, or caffeine or alcohol intake were significant. Logistic regression showed that SHI was the most significant contributing factor to SWD risk (odds ratio [OR] = 1.09, 95% confidence interval [CI] = 1.04 to 1.14). Standardized odds ratio further revealed that with every unit increase on the SHI score, the odds of being at high risk of SWD increased by 80% (OR = 1.84). Most individuals at high risk of SWD reported "always" or "frequently" going to bed at different times (79%) and waking at different times (83%; compared to 58%, p = .017, and 61%, p = .002, respectively for the low-risk group), as well as going to bed stressed/angry (67% vs. 41%, p < .0001) and/or planning/worrying in bed (54% vs. 22%, p < .0001). Interventions aimed at improving sleep hygiene practices and psychological health of shift workers may help reduce the risk of SWD.

Depression and anxiety symptoms correlate with diurnal preference, sleep habits, and Per3 VNTR polymorphism (rs57875989) in a non-clinical sample

BACKGROUND

Evidences suggest that alterations in circadian rhythms trigger the development of mental disorders. Eveningness, sleep behavior, and circadian genes polymorphisms have been associated with depression and anxiety symptomatology. However, the mechanism underlying these interactions is not well understood. We investigated the contribution of diurnal preference, sleep habits, and PER3 VNTR polymorphism (rs57875989) to depression and anxiety symptoms in a Northeast sample from the Brazilian population.

METHODS

Eight hundred and four young adults completed the Morningness-Eveningness (MEQ), Munich Chronotype (MCTQ), Center for Epidemiologic Studies - Depression (CES-D), and Beck Anxiety Inventory (BAI) questionnaires. All participants were genotyped and linear regression was performed to test the interactions between the genetic /behavioral variants and depression/ anxiety symptoms.

RESULTS

Eveningness and sleep behaviors (bedtime, wake-up time, sleep duration, and midpoint of sleep) were correlated with depression symptomatology, specifically in somatic factors of the CES-D questionnaire. No correlation was found between diurnal preference/sleep habits with anxiety symptoms for both BAI total score and its factors. However, women with PER3^4/4 genotype showed less interpesonal affect in depression symptomatology and more anxiety symptoms in four factors of the BAI questionnaire.

LIMITATIONS

Mainly because this study was based on self-report questionnaires and was limited to undergraduate students aging 18 to 30 years old.

CONCLUSION

These results reinforce a role for sleep and diurnal preference in depression, and PER3 VNTR polymorphism in anxiety symptomatology, particularly in women.

The Parent's Chronotype and Child's Sleeping Quality in Association with Relationship Satisfaction

The prospective Ulm-SPATZ study was investigated to assess the role of child sleeping quality between 4 to 6 years of age in affecting a partner's sleeping and relationship satisfaction within a couple. The study was conducted using a triadic approach in which the child was included in the Actor-Partner-Interdependence Model (APIM). Sleeping quality of the child was determined by using the German version of the children's sleep habits questionnaire, sleeping features of the parents were assessed by using the Munich chronotype questionnaire, and the partner relationship assessment was performed by employing the German version of the parenting stress index questionnaire. In 211 German triads, we observed that sleeping characteristics and partner relationship scores at different child ages are consistent for both men and women. Higher and statistically significant sleep duration, time spent in bed, the midpoint of sleep, time getting out of bed, and sleep onset in women compared to men during the working days were observed. The APIM analyses showed a significant direct effect of child sleep quality on the partner relationship satisfaction. In women, a mediated effect of child sleep quality acted through sleep duration and time spent in bed on the partner relationship satisfaction score during both free and working days. In men, low child sleep quality was found to be associated with increased sleep onset during both free and working days. Child sleep quality influences relationship satisfaction mostly in mothers, likely because of their higher involvement in childcare during working days. Distress in the couple could be counteracted by a major involvement of the fathers in child management.

Morningness-eveningness, relationship quality, and quality of life among couples living together

Morningness-eveningness (chronotype) indicates the preferred time of intellectual and physical activity. This cross-sectional study had two main aims. The first aim was to explore associations among chronotype, quality of life, and relationship quality. The second aim of this study was to examine whether the similarities or discrepancies in chronotype between male and female members of the couples were linked to relationship quality. Both members of 143 couples (mean age = 39.44; SD = 10.11y) living together for at least 6 months completed measures of chronotype, marital stress, relationship satisfaction, dyadic coping, satisfaction with life, health-related quality of life, and quality of sleep. Variable-oriented (correlational) and person-oriented (cluster-analytic) analyses were conducted. Variable-oriented analyses showed that morningness was linked to better mental health, and fewer insomnia problems, but less frequent (self-perceived) stress communication for both genders. The discrepancy between the couple's chronotype scores was positively related to the women's sexual and general life satisfaction and more frequent (self-perceived) supportive dyadic coping by the partner. Moreover, ANOVA results showed that Evening-type (E-type) women had the highest mean score on sexual life satisfaction. According to cluster-analytic investigation, couples consisting of two morning-type members had the least frequent stress communication. On the other hand, these couples had better sleeping quality with less insomnia symptoms than couples with two E-type members. In summary, the present findings demonstrate that morningness holds both advantages and disadvantages for both general aspects of life and also the quality of relationships.

Environmental temperature as a mediator on the association between photoperiod at birth and chronotype

The association between chronotypes and season of birth (SOB) remains an inconclusive issue due, in some extension, to the lack of investigations of mediation mechanisms. We evaluated the association of photoperiod at birth (PAB) with chronotypes and sleep duration in Brazil (n = 810), and the mediating effect of meteorological factors, sex, age and rs4753426 polymorphism in the melatonin receptor MTNR1B. Longer PAB was associated with a delayed mid-sleep phase with a suppressive effect of maximum environmental temperature. No significant interactions were identified for the other variables. These findings suggest that photoperiod and environmental temperature modulate chronotype development at early stages.

Circadian typology is related to emotion regulation, metacognitive beliefs and assertiveness in healthy adults

Circadian typology has been related to several mental health aspects such as resilience, perceived well-being, emotional intelligence and psychological symptoms and disorders. However, the relationship between circadian typology and emotion regulation, metacognitions and assertiveness, which constitute core constructs related to psychological well-being and psychopathology, remain unexplored. This study aims to analyze whether circadian typology is related with those three constructs, considering the possible influence of sex. 2283 participants (833 women), aged 18–60 years (30.37 ± 9.26 years), completed the reduced Morningness-Eveningness Questionnaire, the Emotion Regulation Questionnaire, the Meta-Cognitions Questionnaire 30, and the Rathus Assertiveness Schedule. Main effects were observed between circadian typology and cognitive reappraisal, metacognitions, negative beliefs of uncontrollability and danger, cognitive confidence, cognitive self-consciousness, and assertiveness (F_(2,2276) > 4.80, p < 0.009, η_p² > 0.004, in all cases). Morning-type participants scored lower than evening-type in general metacognitive beliefs, negative beliefs of uncontrollability and danger, cognitive confidence, and cognitive self-consciousness, and higher than evening-type in cognitive reappraisal and assertiveness, while neither-type exhibited intermediate scores (p < 0.033 in all cases). According to the results, evening-type individuals might display a higher tendency to support maladaptive beliefs about thinking itself as well as a lesser tendency to reappraise a potentially emotion eliciting situations in order to modify its meaning and its emotional impact and to exert their rights respectfully. This new evidence improves the understanding of the relationships between circadian typology and psychological factors related to psychological well-being and psychopathology. Results implications for the onset and maintenance of psychological problems are discussed. Although future longitudinal studies are needed, results emphasize evening-type as a risk factor for the development of psychological disturbances and morning-type as a protective factor against those.

Circadian preference and relationship satisfaction among three types of couples

Mate selection is part of a growing interest in the study of processes by which couples are established, consolidated and/or separated. Similarity in psychological traits has been related to the well-being of couples, but given the possible effect of temporal convergence, it is necessary to control for the relationship length and whether or not both members of the couple live together. The aim of this study was to analyse the association between Morningness/Eveningness (M/E) similarity and relationship satisfaction in young-dating-non-cohabiting, young-married-cohabiting and old-married-cohabiting couples. Participants included 357 heterosexual couples (357 women and 357 men) with a mean age of 38.42 years old (SD = 13.11; age range between 19 and 69) who completed M/E (Composite Scale of Morningness) and relationship satisfaction measures (Comprehensive Marital Satisfaction Scale). Similarity in M/E was positively related to greater relationship satisfaction in both young cohabiting and non-cohabiting couples. In women, their own M/E was related to their own relationship satisfaction, whereas the level of relationship satisfaction in men was related to their partner's M/E. This relationship was observed in young-married-cohabiting couples. M/E similarity may operate differently as a function of the relationship stage.

Gender differences in chronotype diminish with age: a meta-analysis based on morningness/chronotype questionnaires

Chronotype is an individual difference trait that is closely linked to biological variables. Usually, men and women differ in their chronotype with men being more evening oriented than women. The aim of the study was to assess gender differences in chronotype based on a systematic review and meta-analysis. In addition, many recent studies do not report gender differences any more although researchers collected data on men and women. This motivated us to contact many researchers directly to obtain and use these additional data. We included 164 studies giving 201 effect size measures in a data set, which only included the most commonly used questionnaires (MEQ, rMEQ and CSM) totaling 186,289 participants in total, of which 75,622 were men and 110,667 were women. We calculated an effect size of the standardized mean difference of -0.072 (95% CI from -0.062 to -0.082) in the fixed effects and of -0.066 (95% CI from -0.043 to- 0.089) in the random effects model. Men were on average more evening oriented than women. Type of questionnaire did not influence the standardized mean difference in chronotype between genders. Mean age, standard deviation of age and publication year (p ≤ 0.05) were found to have significant effects on the standardized mean difference in chronotype between genders. The standardized mean difference in chronotype between genders is predicted to change from negative to positive with increasing mean age (young women were more morning orientated than young men, but older women were less morning orientated than older men). This suggests that the differences between men and women diminish with time. The standardized mean difference in chronotype between genders is decreasing with increasing publication year, as well as with high variation in age of the samples. Abbreviations: CSM: Composite Scale of Morningness (Smith et al. 1989); MEQ: Morningness-Eveningness Questionnaire (Horne and Ostberg, 1976); rMEQ: reduced Morningness-Eveningness Questionnaire (Adan & Almiral, 1991); SMD: standardized mean difference (measure of effect size).

Chronobiology of limbic seizures: Potential mechanisms and prospects of chronotherapy for mesial temporal lobe epilepsy

Mesial Temporal Lobe Epilepsy (mTLE) characterized by progressive development of complex partial seizures originating from the hippocampus is the most prevalent and refractory type of epilepsy. One of the remarkable features of mTLE is the rhythmic pattern of occurrence of spontaneous seizures, implying a dependence on the endogenous clock system for seizure threshold. Conversely, circadian rhythms are affected by epilepsy too. Comprehending how the circadian system and seizures interact with each other is essential for understanding the pathophysiology of epilepsy as well as for developing innovative therapies that are efficacious for better seizure control. In this review, we confer how the temporal dysregulation of the circadian clock in the hippocampus combined with multiple uncoupled oscillators could lead to periodic seizure occurrences and comorbidities. Unraveling these associations with additional research would help in developing chronotherapy for mTLE, based on the chronobiology of spontaneous seizures. Notably, differential dosing of antiepileptic drugs over the circadian period and/or strategies that resynchronize biological rhythms may substantially improve the management of seizures in mTLE patients.

Chronotype and suicide: The mediating effect of depressive symptoms

BACKGROUND

Chronotype is individual characteristic, and people who stay up late are acknowledged to be more likely to experience depressive symptoms as well as impulsivity and suicide. Depression is also associated with suicidality. The purpose of this study was to investigate and analyze the role of depression in its effects on chronotype and suicidality.

METHOD

A total of 5632 university students were recruited as participants. We evaluated their chronotype, depressive symptoms, and suicidality using questionnaires. Correlation analysis, analysis of covariance, and path analysis were performed.

RESULTS

Depressive symptoms and suicidality were higher among individuals with an eveningness chronotype: the greater the depressive symptoms, the higher the suicidality. The results of path analysis showed that the direct effect of suicidality in relation to chronotype was not statistically significant, but the indirect effect of depressive symptoms was statistically significant. This result indicates that depressive symptoms fully mediated the relationship between chronotype and suicidality.

CONCLUSION

Morningness may be a protective factor, not only against depression but also against suicide. To assess the risk of suicide, we must evaluate not only depressive symptoms, but also the effects of chronotype on depressive symptoms.