Morningness-Eveningness Questionnaire Scores Research Articles

Predicting the actigraphy-based acrophase using the Morningness–Eveningness Questionnaire (MEQ) in college students of North Italy

ABSTRACTActigraphy is the reference objective method to measure circadian rhythmicity. One simpler subjective approach to assess the circadian typology is the Morningness–Eveningness Questionnaire (MEQ) by Horne and Ostberg. In this study, we compared the MEQ score against the actigraphy-based circadian parameters MESOR, amplitude and acrophase in a sample of 54 students of the University of Milan in Northern Italy. MEQ and the acrophase resulted strongly and inversely associated (r = −0.84, p < 0.0001), and their relationship exhibited a clear-cut linear trend. We thus used linear regression to develop an equation enabling us to predict the value of the acrophase from the MEQ score. The parameters of the regression model were precisely estimated, with the slope of the regression line being significantly different from 0 (p < 0.0001). The best-fit linear equation was: acrophase (min) = 1238.7–5.49·MEQ, indicating that each additional point in the MEQ score corresponded to a shortening of the acrophase of approximately 5 min. The coefficient of determination, R2, was 0.70. The residuals were evenly distributed and did not show any systematic pattern, thus indicating that the linear model yielded a good, balanced prediction of the acrophase throughout the range of the MEQ score. In particular, the model was able to accurately predict the mean values of the acrophase in the three chronotypes (Morning-, Neither-, and Evening-types) in which the study subjects were categorized. Both the confidence and prediction limits associated to the regression line were calculated, thus providing an assessment of the uncertainty associated with the prediction of the model. In particular, the size of the two-sided prediction limits for the acrophase was about ±100 min in the midrange of the MEQ score. Finally, k-fold cross-validation showed that both the model’s predictive ability on new data and the model’s stability to changes in the data set used for parameter estimation were good. In conclusion, the actigraphy-based acrophase can be predicted using the MEQ score in a population of college students of North Italy.

Association between depressive symptoms and morningness-eveningness, sleep duration and rotating shift work in Japanese nurses

ABSTRACTHigher depressive symptoms have been reported in rotating shift workers compared with day workers. Depressive symptoms in adults who do not engage in night work have also been shown to be associated with chronotype and sleep duration. This study examines associations between depressive symptoms, morningness-eveningness (i.e. the degree to which people prefer to be active in the morning or the evening), sleep duration and rotating shift work. Japanese nurses (1252 day workers and 1780 rotating shift workers, aged 20–59) were studied using a self-administered questionnaire. The questionnaire covered depressive symptoms, morningness-eveningness, sleep habits and demographic characteristics of the participants. The Center for Epidemiologic Studies Depression Scale (CES-D) was used to determine the levels of depressive symptoms. A Japanese version of the Morningness-Eveningness Questionnaire (MEQ) was used to measure morningness-eveningness. The CES-D score of shift workers was significantly (p < 0.05) higher than that of day workers. The MEQ score was significantly (p < 0.05) lower (i.e. greater eveningness) in shift workers than in day workers. Sleep duration on the day shift was significantly (p < 0.05) shorter in shift workers than in day workers. Simple linear regression revealed that the MEQ score, sleep duration on the day shift and current work shift (i.e. rotating shift work) were significantly (p < 0.05) associated with the CES-D score. Multivariate linear regression indicated that greater eveningness and shorter sleep duration were independently associated with higher CES-D scores, while rotating shift work was not. These associations between the MEQ score, the sleep duration and the CES-D score were also confirmed in both day workers and shift workers when the groups were analyzed separately. These results suggest that greater eveningness and shorter sleep duration on the day shift were independently associated with higher levels of depressive symptoms, which may explain associations between rotating shift workers and depressive symptoms. These findings have important implications for the development of novel strategies for preventing poor mental health in day workers and rotating shift workers.

A chronobiological approach to therapy for depression

In the modern world, the discrepancy between biological and social rhythms in the presence of the existing genetic predisposition increases a risk for the occurrence and chronicity of depression. To solve this problem, various approaches, including a chronobiological one, are applied. Objective: to explore the relationship between chronobiological characteristics and psychopharmacotherapy in patients with depression. Patients and methods Eighty patients with depression, among whom women (68.7%) predominated, were examined. The age of the patients was 18–75 years (47.6±15.6 years). Their chronotype was identified using the Morningness–Eveningness Questionnaire (MEQ) to determine the type of circadian rhythm. Changes in the patients' status were clinically assessed utilizing the psychometric indicators. Results. Sleep disorders were most pronounced in recurrent depression (4.1±1.1 scores) (Montgomery–Asberg Depression Rating Scale, MADRS, item 4). The inverted pattern of daily variations was more frequently observed in patients with a first depressive episode (p<0.05). According to MEQ scores, the investigators identified three groups of patients with morning (5%), intermediate (65%), and evening (30%) chronotypes. At the same type, the latter chronotype was clearly associated with the positive family history of affective disorders, earlier onset of depression, a larger number of experienced episodes, a higher average duration of an episode in the history, younger age, and severe condition when visiting a physician's office required additional psychopharmacotherapy. It was more effective to use antidepressants in the morning, if the patient had an evening chronotype, and in the evening, if he/she had a morning/intermediate chronotype. Conclusion. The patients with initially different chronotypes showed differences in the premorbid, onset, and course of the disease. The account of a chronotype can be considered as one of the approaches to optimize psychopharmacotherapy.

Circadian phase typing in idiopathic generalized epilepsy: Dim light melatonin onset and patterns of melatonin secretion-Semicurve findings in adult patients.

It has been debated in the literature whether patients with idiopathic generalized epilepsy (IGE) have a distinctive, evening-oriented chronotype. The few questionnaire-based studies that are available in the literature have conflicting results. The aim of our study was to define chronotype in patients with IGE by determining dim light melatonin onset (DLMO). Twenty adults diagnosed with IGE (grand mal on awakening [GM] in 7 cases and juvenile myoclonic epilepsy in 13 cases) were investigated by means of a face-to-face semistructured sleep interview, Morningness-Eveningness Questionnaire (MEQ), Pittsburgh Sleep Quality Index (PSQI) questionnaire, and a melatonin salivary test with DLMO determination. Eighteen healthy subjects (HC) and 28 patients affected with cryptogenic focal epilepsy (FE) served as controls. The mean MEQ score was significantly lower in patients with IGE than that in patients with FE (49.1±5.9 versus 56.1±8.7 P<0.01) but not significantly lower than that in HC (49.1±5.9 versus 49.3±8.6). Midsleep on free days corrected for sleep duration did not differ significantly between the three subject groups (04:59±01:21h, 04:37±01:17h, 04:29±00:52h). The mean DLMO time in patients with IGE (22:13±01:34h) occurred 49min later than that in HC (21.24±1h), and the melatonin surge within the 30-minute time interval after DLMO in patients with IGE was significantly lower than that in HC (1.51±2.7 versus 3.8±3.6pg/mL P=0.045). Subjective measures of chronotype do not indicate a definite evening-oriented chronotype in patients with IGE. However, the data concerning endogenous melatonin secretion indicate that patients with IGE tend to have a late circadian phase. Further studies are warranted in order to better define the late pattern of endogenous melatonin secretion in patients with IGE and to ascertain the role of this pattern in influencing behavioral chronotype in these subjects.

Antidepressant chronotherapeutics in a group of drug free outpatients

The combination of Total Sleep Deprivation (TSD) and Light Therapy (LT) has been shown to prevent the early relapses characterizing response to TSD. Despite their proved efficacy, TSD and LT are still far from being considered standard therapy in the inpatient units and no study has assessed their efficacy and feasibility in outpatient settings. We studied 27 drug-free out-patients affected by Major Depression, divided in 7 groups according to the date of the wake night. Patients were administered one night of TSD and received LT during consecutive mornings following a predictive algorithm based on Morningness-Eveningness Questionnaire scores. Severity of depression was rated on Back Depression Inventory Scale (BDI) at baseline, one week and three months after the end of treatment. BDI scores significantly decreased during treatment with no difference between the seven consecutively treated groups of patients. Significant differences in BDI scores were confirmed between the baseline and both one week and three months after the end of treatment. TSD and LT caused a significant amelioration of depressive symptoms in an outpatient setting. Similar effects were observed in seven independent groups, suggesting that there is repeatability in findings. Chronotherapeutics confirmed their efficacy in the treatment of depression.

Associations of pineal volume, chronotype and symptom severity in adults with attention deficit hyperactivity disorder and healthy controls

The pineal gland, as part of the human epithalamus, is the main production site of peripheral melatonin, which promotes the modulation of sleep patterns, circadian rhythms and circadian preferences (morningness vs. eveningness). The present study analyses the pineal gland volume (PGV) and its association with circadian preferences and symptom severity in adult ADHD patients compared to healthy controls. PGV was determined manually using high-resolution 3T MRI (T1-magnetization prepared rapid gradient echo) in medication free adult ADHD patients (N=74) compared to healthy controls (N=86). Moreover, the Morningness–Eveningness Questionnaire (MEQ), the ADHD Diagnostic Checklist and the Wender–Utah Rating Scale were conducted. PGV differed between both groups (patients: 59.9±33.8mm3; healthy controls: 71.4±27.2mm3, P=0.04). In ADHD patients, more eveningness types were revealed (patients: 29%; healthy controls: 17%; P=0.05) and sum scores of the MEQ were lower (patients: 45.8±11.5; healthy controls 67.2±10.1; P<0.001). Multiple regression analyses indicated a positive correlation of PGV and MEQ scores in ADHD (β=0.856, P=0.003) but not in healthy controls (β=0.054, P=0.688). Patients’ MEQ scores (β=−0.473, P=0.003) were negatively correlated to ADHD symptoms. The present results suggest a linkage between the PGV and circadian preference in adults with ADHD and an association of the circadian preference to symptom severity. This may facilitate the development of new chronobiological treatment approaches for the add-on treatment in ADHD.

大学生心理健康、自我调节对时型的影响

目的：探讨大学生时型和心理健康、自我调节之间的关系。方法：选取某大学314名在校学生为被试，共收回298份有效问卷。采用清晨型/夜晚型问卷(MEQ)调查被试的时型，一般健康问卷(GHQ-12)测量被试的心理健康水平，自我控制量表中文版(SCS)和拖延量表(PS)测量被试的自我调节能力。结果：MEQ问卷平均得分(49.41 ± 8.07)，GHQ-12问卷平均得分(25.73 ± 5.00)，SCS量表平均得分(55.97 ± 8.74)，PS量表平均得分(42.12 ± 6.49)。各个量表分数之间均有显著相关(r = −0.6~0.78, p < 0.01)，年级与MEQ总分呈显著负相关(p < 0.01)。回归分析显示，PS总分、SCS总分和年级对MEQ总分的预测作用显著(R2 = 0.24)，SCS的分量表健康习惯和节制娱乐、以及年级能显著预测MEQ总分(R2 = 0.34)。中介效应检验显示，自我调节系数在心理健康与时型之间起完全中介作用。结论：年级和自我调节能力可以预测时型，心理健康可以通过自我调节能力影响时型。 Objective: To explore the relation of self-regulation to mental health and subjective chronotype in college students. Methods: 314 college students were chosen as subjects from one college in Guang-dong province. And we got 298 effective copies. Morningness/Eveningness Questionnaire (MEQ) was chosen to test the chronotype. General Health Questionnaire 12 Items (GHQ-12) was chosen to test the degree of mental health. Self-Control Scale (SCS) and Procrastination Scale (PS) were together used to measure Self-regulation. Results: The average score of MEQ in college students was (49.41 ± 8.07). The average score of GHQ-12 was (25.73 ± 5.00). The average score of SCS was (55.97 ± 8.74) and the average score of PS was (42.12 ± 6.49). The score of each scale significantly correlates with each other (r = −0.6 - 0.78, p < 0.01) and in variables of demology, only grades have a significantly negative correlation with the average score of MEQ (p < 0.01). Regression analysis revealed that the PS score, SCS score and grade can significantly predict the MEQ score (R2 = 0.24). Grades and the sub- scale of MEQ: healthy habits and controling entertainment can significantly predict the MEQ score (R2 = 0.34). To test the mediating effect, we found that self-regulation coefficient played a completely mediating role in the relation between mental health and chronotype. Conclusion: Grades and self-regu- lation can predict chronotype and mental health can affect chronotype through self-regulation ability.

의대의학전문대학원 학생들의 삶의 질과 일주기 리듬 및 수면의 질과의 연관성

목 적 : 의학전문대학원생들은 의학교육과정 동안 심한 스트레스와 수면 부족을 경험한다. 따라서 의전원생들의 수면 양상, 불면의 정도, 일주기 리듬이 삶의 질과 어떠한 연관성이 있는지 알아보고자 하였다. 방 법 : 경상대학교 의학전문대학원(의전원) 4학년 46명을 대상으로 하였다. 병원 불안-우울 척도, 불면증 심각성 척도, 아침형-저녁형 문항과 삶의 질을 측정하기 위한 세계보건기구 삶의 질 간편형 척도를 사용하였다. 삶의 질과 연관된 요인들을 밝히기 위하여 피어슨 상관분석을 시행하였고 상관성 있는 변수들을 선정하여 다중회귀분석을 시행하였다. 결 과 : 의전원 학생들 중 13명에서 약간의 불면증 경향이 있었다. 명백한 저녁형은 3명, 중등도 저녁형은 12명, 중간형은 28명, 중등도 아침형은 3명이었으며 명백한 아침형은 없었다. 피어슨 분석에서 신체적 영역의 삶의 질과 연관을 보인 요소들은 나이, 주중 및 주말 평균 수면시간, 주중과 주말의 수면 차, 우울, 불면증의 심각성 정도, 아침형-저녁형 점수였고 심리적 영역의 삶의 질과 연관을 보인 요소들은 주중 및 주말의 평균 수면, 불안, 불면증의 정도와 아침형-저녁형 점수였다. 사회적 영역의 삶의 질에서는 성별, 주중 평균 수면시간, 우울, 불면증 점수가 연관성이 있었고, 환경적 영역의 삶의 질에서는 주중 및 주말의 평균 수면시간과 불면증의 심각성 정도가 연관성이 있었다. 다중회귀분석을 통하여 불면증의 심각도가 낮을수록 신체적 건강영역, 심리적 영역과 환경적 영역의 삶의 질이 높고, 저녁형 일수록 신체적 건강 영역과 심리적 영역의 삶의 질이 높은 것으로 나타났다. 결 론 : 의전원 학생들에서 수면의 질이 좋을수록 신체적 및 심리적, 환경적 영역의 삶의 질이 높았고, 저녁형일수록 신체적 및 심리적 영역의 삶의 질이 높았다. 이를 통해 학생들의 수면 습관 개선이 정서적 문제에 대한 개입 못지 않게 중요하다는 것을 알 수 있다. Objectives: We investigated whether sleep behaviors, severity of insomnia and circadian typology are associated with quality of life among Gyeongsang National University (GNU) medical students. Methods: Questionnaires were distributed to 46 fourth-year students of GNU Medical School. The hospital anxiety-depression scale, insomnia severity index (ISI), morningness-eveningness questionnaire (MEQ) and WHO Quality of Life-BREF (WHOQOL-BREF) were used. Results: Quality of life in terms of physical health was associated with age, weekday total sleep time (TST), weekend TST, catch up sleep, depression, ISI score, and MEQ score. Quality of life in terms of psychological health was correlated to weekday and weekend TST, anxiety, ISI score and MEQ score. Sex, weekday TST, depression, and ISI score were revealed to influence the social aspect of quality of life, and weekday and weekend TST, and ISI score were associated with quality of life in terms of environment. Multiple regression analysis showed that better sleep quality predicted to a higher quality of life in terms of physical, psychological and environmental health, and eveningness was associated with a better quality of life in terms of physical and psychological health. Conclusion: It is concluded that physical, psychological, and environmental aspects of quality of life were associated with quality of sleep and that physical and psychological aspects of quality of life were related to eveningness in GNU medical students. Therefore, it is equally important to treat emotional problem as well as improve sleep quality.

Successful weight loss maintenance associated with morning chronotype and better sleep quality.

It is not known whether individuals successful at long term weight loss maintenance differ in chronotype (i.e., being a "morning" or "evening" person) or sleep habits compared to those who are overweight and obese. We compared Morningness-Eveningness Questionnaire (MEQ) and Pittsburgh Sleep Quality Index scores of 690 National Weight Control Registry (NWCR) members (73% female, 93% white, age=51.7±12.5, BMI=26.4±5.1) to 75 enrollees in two behavioral weight loss interventions (INT; 77% female, 88% white, age=55.7±10.4, BMI=36.2±4.7). Controlling for age, MEQ scores were higher in NWCR than INT, p=.004, such that more NWCR than INT were morning-types and fewer were evening types, p=.014. Further, NWCR participants reported better sleep quality, longer sleep duration, and shorter latency to sleep onset compared to INT, ps<.05, and fewer NWCR participants reported <6 or <7h of sleep, ps<.01. Future studies should examine if these factors change as a result of weight loss or are predictors of weight outcome.

The influence of school time on sleep patterns of children and adolescents

ObjectiveThis epidemiological study evaluated the impact of school time on sleep parameters of children and adolescents. MethodsThis cross-sectional study involved 639 elementary and high school students (mean age 13.03 years, range 8–18, 58.5% female) from the south of Brazil. Participants answered the Morningness-Eveningness Questionnaire (MEQ), and were asked about their sleeping habits on weekdays and weekends. Sleep deficit was defined as the difference between sleep duration on weekdays and weekends. ResultsThe morning-school-time students presented significantly higher age, bedtime and wake up differences, sleep deficits, and social jetlag. The sleep deficit presented by girls was greater than that observed in boys of the same age. The difference between weekday and weekend waking times was also significantly greater in girls than in boys aged 13–18 years. Sleep deficit was significantly positively correlated with age and differences in wake up times, and significantly negatively correlated with MEQ scores, social jetlag, difference between weekday and weekend bedtimes, midpoint of sleep on weekends, and midpoint of sleep on weekends corrected for sleep deficit. A step-by-step multivariate logistic regression identified social jetlag, the difference between waking times on weekdays and weekends, and the midpoint of sleep on weekends as significant predictors of sleep deficit (Adjusted R2 = 0.95; F = 1606.87; p < 0.001). ConclusionThe results showed that school time influences the sleep parameters. The association of school schedules and physiological factors influence the sleep/wake cycle.

Chronotype and its relationship to sleep quality in patients with affective disorders and co-occurring insomnia

Introduction: Poor sleep is common in depression, has been shown to precede acute episodes, and persists during remission. Circadian abnormalities are involved in the pathogenesis of depression and are one of the prominent factors underlying sleep disturbances. Therefore, we studied the relation between circadian preferences (chronotype) and sleep quality in patients with affective disorders accompanied by clinically relevant insomnia. Methods: Forty-eight inpatients (29 f/19 m; age: 42.5 ± 14.2 years) with mainly depressive disorders (ICD-10: F32/33) and co-occurring insomnia complaints (Pittsburgh Sleep Questionnaire Index, PSQI global sore ≥ 5) completed the Morningness-Eveningness Questionnaire (MEQ) and the Beck Depression Inventory-II (BDI). Results: Patients were classified as 12 evening types, 25 intermediate types, and 11 morning types. Chronotypes did not differ in BDI-II, but substantial age differences were found: evening types were younger than intermediate types (p < 0.05) and morning types (p < 0.01). When compared with evening types or intermediate types, morning types showed a shorter sleep duration as assessed by the PSQI (each p < 0.05). Correlation analyses revealed a positive relationship between MEQ scores and the PSQI subscale sleep efficiency (the higher the MEQ score towards morningness, the lower the sleep efficiency) (p < 0.05), although this association was found to be mediated by age. Evening types exhibited a tendency towards a longer sleep latency (p < 0.1).

Chronotype in patients with epilepsy: A controlled study in 60 subjects with late-onset focal epilepsy.

Studies based on self-administered questionnaires indicate that most patients with epilepsy are morning-oriented. We aimed to investigate chronotype in patients with epilepsy with late-onset focal epilepsy by combining subjective data with dim light melatonin onset (DLMO) as an objective marker of the circadian phase. Sixty adult patients (mean age 46.5±13.8; 27 males) with late-onset focal epilepsy under pharmacological treatment were prospectively studied. Subjective chronotype was determined using the Morningness-Eveningness Questionnaire (MEQ) and circadian phase through analysis of salivary melatonin secretion, considering 3pg/ml as the dim light melatonin onset (DLMO) threshold. The mean MEQ score was significantly higher in the patients with epilepsy than in the controls, and significantly, more patients had a MEQ score indicative of the morning type (50.0% vs 30.0%, p=0.02). However, no significant differences were found in mean time of DLMO (21:38±01:21 vs 21:26±01:03; p=ns), and DLMO time was in the range indicative of an intermediate chronotype in both patients and controls. Sleep onset and sleep offset phase angles were significantly shorter in the patients. Patients whose global MEQ score identified them as morning types were significantly older than those with an intermediate or evening chronotype, and they had less social jet lag. No difference in epilepsy features and treatments was found between morning-oriented and nonmorning-oriented patients. Our analyses showed that the patients with epilepsy tended to be morning-oriented and to perceive themselves as morning types, even though this was not reflected in their DLMO values which did not differ significantly from those of controls and mostly fell within the intermediate chronotype range. Several factors may considerably influence subjective chronotype. We speculate that, in patients with epilepsy, the disease itself, prompting certain lifestyle choices, including a regular sleep schedule and early bedtime, may induce morning orientation and a morning-type self-perception.

Distribution and heritability of diurnal preference (chronotype) in a rural Brazilian family-based cohort, the Baependi study.

Diurnal preference (chronotype) is a useful instrument for studying circadian biology in humans. It harbours trait-like dimensions relating to circadian period and sleep homeostasis, but also has ontogenetic components (morningness increases with age). We used the Morningness-Eveningness questionnaire (MEQ) in the Baependi study, a family-based cohort study based in a small town in Minas Gerais, Brazil. The population is highly admixed and has a cohesive and conservative lifestyle. 825 individuals (497 female) aged 18–89 years (average ± SD = 46.4 ± 16.3) and belonging to 112 different families participated in this study. The average MEQ score was 63.5 ± 11.2 with a significant (P < 0.0001) linear increase with age. Morningness was significantly (P < 0.0001) higher in the rural (70.2 ± 9.8) than in the municipal zone (62.6 ± 11.1), and was also significantly (P = 0.025) higher in male (64.6 ± 10.9) than in female (62.8 ± 11.2) participants. Thus, in spite of universal access to electricity, the Baependi population was strongly shifted towards morningness, particularly in the rural zone. Heritability of MEQ score was 0.48 when adjusted for sex and age, or 0.38 when adjusted for sex, age, and residential zone. The reported MEQ score heritability is more akin to those of previous twin studies than previous family studies.

Chronotype and seasonality: Morningness is associated with lower seasonal mood and behavior changes in the Old Order Amish

BackgroundSeveral studies documented that lower scores on the Morningness–Eveningness Questionnaire (MEQ) are associated with a higher global seasonality of mood (GSS). As for the Modern Man artificial lighting predominantly extends evening activity and exposure to light, and as evening bright light phase is known to delay circadian rhythms, this chronic exposure could potentially lead to both lower Morningness as well as higher GSS. The aim of the study was to investigate if the MEQ–GSS relationship holds in the Old Order Amish of Lancaster County, PA, a population that does not use network electrical light. Methods489 Old Order Amish adults (47.6% women), with average (SD) age of 49.7 (14.2) years, completed both the Seasonal Pattern Assessment Questionnaire (SPAQ) for the assessment of GSS, and MEQ. Associations between GSS scores and MEQ scores were analyzed using linear models, accounting for age, gender and relatedness by including the relationship matrix in the model as a random effect. ResultsGSS was inversely associated with MEQ scores (p=0.006, adjusted). Limitationsinclude a potential recall bias associated with self-report questionnaires and no actual light exposure measurements. ConclusionWe confirmed the previously reported inverse association between MEQ scores and lower seasonality of mood, for the first time in a population that does not use home network electrical lighting. This result suggests that the association is not a byproduct of exposure to network electric light, and calls for additional research to investigate mechanisms by which Morningness is negatively associated with seasonality.

Temporal sleep patterns in adults using actigraph

The aim of the present study was to characterize the temporal patterns of sleep and wakefulness in a sample of the adult subjects from São Paulo city. All subjects filled the Morningness/Eveningness Questionnaire (MEQ) and wore an actigraph for at least three consecutive days. A total of 359 subjects were considered for the analyses. The mean age was 43±14 years, the mean body mass index was 26.7±5.7kg/m2, and 60% were female. The mean MEQ score was 58.0±10.7. The sleep pattern evaluated by the actigraphic analyses showed that 92% had a monophasic sleep pattern, 7% biphasic, and 1% polyphasic sleep pattern. Cluster analysis, based on time to sleep onset, sleep efficiency, sleep latency, and total sleep time, was able to identify three different groups denominated: morning type, evening type, and undefined type. Morning type subjects were more frequent, older, and had higher MEQ scores than evening type subjects. Our results showed that the actigraph objectively assessed the sleep-wake cycle and was able to discriminate between morning and evening type individuals. These findings suggest that the actigraph could be a valuable tool for assessing temporal sleep patterns, including the circadian preferences.

Validity and reliability of the Japanese version of the Morningness-Eveningness Questionnaire evaluated from actigraphy

The purposes of this study were to investigate the validity and reliability of the Japanese version of Horne and Ostberg’s Morningness-Eveningness Questionnaire (MEQ) and the characteristics of chronotype using other questionnaires and wrist actigraphy in healthy young subjects. The participants were 102 university student volunteers. The participants were instructed to continue normal life activities and habitual sleep-wake rhythms without extraordinary events for a study period of eight consecutive days, including 7 nights. Actual sleep-wake patterns were recorded by wrist actigraphy. The participants completed four questionnaires: MEQ, Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI), and Center for Epidemiologic Studies Depression Scale (CES-D). From the actigraphy data, sleep parameters such as bedtime, waketime, midtime, time in bed, sleep onset latency, wake episodes, wake after sleep onset, total sleep time, and sleep efficiency were derived. Cronbach’s α coefficient for internal consistency of the total MEQ score was 0.815, indicating high reliability. One-way analyses of variance showed that there were significant differences among the three chronotypes for bedtime, waketime, midtime, ESS, PSQI, and CES-D. Pearson’s correlation coefficients revealed that there were moderate negative correlations between MEQ scores and bedtime, waketime, and midtime, and that there were weak negative correlations between MEQ scores and ESS scores, PSQI scores, and CES-D scores. The results of this study demonstrated the validity and reliability of the Japanese version of the MEQ. In addition, the findings of this study showed that evening chronotypes were associated with greater daytime sleepiness, poorer sleep quality, and a depressive tendency.

Validity of the Japanese version of the Munich ChronoType Questionnaire

To assess circadian preference with a score, the Morningness-Eveningness Questionnaire (MEQ) has been used for more than 3 decades now. More recently, the Munich ChronoType Questionnaire (MCTQ) was developed: it asks for sleep-wake behavior on work and free days and uses the midpoint of sleep on free days (MSF), corrected for sleep debt accumulated during the work week as an indicator of chronotype (MSFsc). In this study, we developed a Japanese version of the MCTQ by using a translation/back-translation approach including an examination of its semantic validity. In a subsequent questionnaire survey, 450 adult men and women completed the Japanese versions of the MCTQ and MEQ. Results showed that MEQ scores were significantly negatively correlated with mid-sleep parameters assessed by the MCTQ, on both, work and free days, as well as with the chronotype measure MSFsc (r = −0.580 to −0.652, all p < 0.001). As in the original German version, the strongest correlation was observed between MEQ score and MSF. A physiological validation study using dim light melatonin onset as a circadian phase marker (N = 37) showed a high correlation between chronotype as assessed with the MSFsc (r = 0.542, p < 0.001), and less so for MEQ score (r = −0.402, p = 0.055). These results demonstrate the validity of the Japanese MCTQ and provide further support of the adequacy of the MCTQ as a chronotype measure.

Eveningness Chronotype, Daytime Sleepiness, Caffeine Consumption, and Use of Other Stimulants Among Peruvian University Students.

Objectives: The aims of this study were to evaluate patterns of circadian preferences and daytime sleepiness, and to examine the extent to which the consumption of stimulant beverages is associated with daytime sleepiness and evening chronotype among Peruvian college-age students. Methods: A total of 2,581 undergraduate students completed a self-administered comprehensive questionnaire that gathered information about sleep habits, sociodemographic and lifestyle characteristics, and the use of caffeinated beverages. The Morningness-Eveningness Questionnaire (MEQ) and Epworth Sleepiness Scale (ESS) were used to assess chronotype and daytime sleepiness. We used multivariable linear and logistic regression procedures to estimate odds ratios (OR) and 95% confidence intervals (95% CI) for the associations of sleep disorders with sociodemographic and behavioral factors. Results: The prevalence of daytime sleepiness was 35% [95% CI 32.7-36.4] and eveningness chronotype was 10% [95% CI 8.8-11.1%]. Age, sex, cigarette smoking, and alcohol consumption were significantly associated with an evening chronotype. After adjusting for age, sex, smoking, body mass index, and physical activity, students who reported consumption of any stimulant beverages had 1.25 increased odds of excessive daytime sleepiness (OR=1.25 [95% CI 1.03-1.53]) compared with students who did not consume stimulant beverages. Consumption of any stimulant beverages was not statistically significantly associated with being an evening chronotype (OR=1.30 [95% CI 0.86-1.96]). Conclusions: Excessive daytime sleepiness and eveningness chronotype are common among Peruvian college students. MEQ scores were associated with age, sex, smoking, and alcohol consumption. Regular stimulant beverage consumption tended to be positively associated with excessive daytime sleepiness.

Reliability and validity of the Korean version of Morningness–Eveningness Questionnaire in adults aged 20–39 years

Morningness–Eveningness (ME) can be defined by the difference in individual diurnal preference observed from general behavioral patterns including sleep habits. The Horne & Östberg Morningness–Eveningness Questionnaire (MEQ) has been used for classifying ME types. We examined the reliability of a Korean version of the MEQ (Korean MEQ) and verified its validity by comparing responses on the Korean MEQ to objectively-recorded sleep–wake rhythms. After translating and back translating the MEQ from English into Korean, we examined the internal consistency of 19 items of the Korean MEQ in 91 subjects, and the test–retest reliability in 21 subjects who took the Korean MEQ twice, 4 weeks apart. The Korean MEQ was then administered to 1022 young adult subjects. A subset of 46 morning, neither, and evening type subjects took part in a validation study in which their rest-activity timing was collected by actigraphy for 7 days. Cosinor analyses on these data were done to obtain the acrophase and amplitude of the sleep–wake rhythm. Cronbach’s alpha of the total scores from the Korean MEQ was 0.77, and the test–retest reliability intra-class correlation coefficient was 0.90 (p < 0.0001). There was a significant negative correlation between Korean MEQ score and reported sleep–wake timing among the entire cohort (p < 0.0001). There was a significant difference in bedtime and wake time (on both work and free days), and in the mean sleep–wake rhythm acrophase, between ME types (p < 0.01). In this study, the validity of the Korean MEQ was verified by illustrating the difference in acrophases of the sleep–wake rhythm between the ME types in young adults.

Predictors of poor sleep quality among Lebanese university students: association between evening typology, lifestyle behaviors, and sleep habits

Adequate, good night sleep is fundamental to well-being and is known to be influenced by myriad biological and environmental factors. Given the unavailability of sleep data about Lebanon, the cultural shifts and socioeconomic pressures that have affected many aspects of society, particularly for students and working adults, as well as our understanding of sleep in university students in other countries, we conducted a national study to assess sleep quality and factors contributing to sleep and general health in a culture-specific context. A self-filled questionnaire, inquiring about sociodemographics, health-risk behaviors, personal health, and evaluating sleep quality and chronotype using standard scales was completed by 540 students at private and public universities in Lebanon. Overall, they reported sleeping 7.95±1.34 hours per night, although 12.3% reported sleeping <6.5 hours and more than half scored in the poor-sleeper category on the Pittsburgh Sleep Quality Index (PSQI). Sleep timing differed markedly between weekdays and weekends, with bedtimes and wake-up times delayed by 1.51 and 2.43 hours, respectively, on weekends. While most scored in the “neither type” category on the Morningness–Eveningness Questionnaire (MEQ), 24.5% were evening types and 7.3% were morning types. MEQ score was significantly correlated with smoking behavior and daily study onset, as well as with PSQI score, with eveningness associated with greater number of cigarettes, later study times, and poor sleep. We conclude that the prevalence of poor sleep quality among Lebanese university students is associated with reduced sleep duration and shifts in sleep timing between weekdays and weekends, especially among evening types. While chronotype and certain behavioral choices interact to affect sleep dimensions and quality, raising awareness about the importance of obtaining adequate nighttime sleep on daily performance and avoiding risky behaviors may help Lebanese students make better choices in school and work schedules.