Children's Chronotype Research Articles

Bullying and victimization in schools: Causal relationship between adolescent disruptive behavior, sleep schedules, and extended school hours

AbstractVery few studies have identified the relationship between chronotype, sleep habits, and bullying/victimization in school and online contexts. The objective of this work is to identify predictors of frequency of bullying/cyberbullying in Portuguese pubescent and adolescent populations, such as chronotype and sleep aspects, controlling for gender, age, grade, and school attendance hours. One hundred and seventeen Portuguese students from the second and third grades of elementary school were considered, 41 (34.5%) of which were males and 76 (63.9%) were females. The measures used were the Children's Chronotype Questionnaire and the Bullying and Cyberbullying Behaviors Questionnaire: Short Form (BCBQ‐SF). Percentile analyses, multivariate analysis of variance, nonparametric tests, and hierarchical and nonhierarchical linear logistic regression analyses were performed to confirm the prediction models and to identify causal variables moderating the effect of bullying and victimization in adolescents of various ages and school grades, with different school and sleep schedules. Adolescents with more episodes of victimization had higher sleeping problems, especially in terms of sleep duration (late hours of awakening/rest times and falling asleep, especially on days off); the school grade, the average daily school attendance hours, and school entrance time were some predictors found. The model differed in the variable of hours of curricular enrichment activities. The higher the eveningness score, the more aggression was reported.

Associations between sleep characteristics and glycemic variability in youth with type 1 diabetes

ObjectiveThis study aimed to determine sleep characteristics and their associations with glycemic variability in youth with type 1 diabetes (T1D). Material and methodsThis cross-sectional study conducted at two pediatric diabetes centers in Istanbul, Turkey, included 84 children with T1D (mean age 10.5 years). Sleep characteristics and glycemic variability were determined by actigraphy, DSM-5 Level 2-Sleep Disturbance Scale Short Form and continuous glucose monitoring. Circadian preference was evaluated by the Children's Chronotype Questionnaire. Sleep disturbances were assessed by the. The sleep quality was determined by actigraphy-derived sleep measures. ResultsEighty-eight percent of participants had insufficient age-appropriate total sleep time (TST) (<9 h for 6–13-year-olds and <8 h for 14–17-year-olds). Chronotype was classified as intermediate in 50%, evening in 45.2%, and morning in 4.8%. A higher chronotype score indicating a stronger eveningness preference was associated with more time spent in hypoglycemia (β = 0.433, p = 0.002). On nights when participants had lower sleep efficiency and longer sleep onset latency, they had significantly higher overnight glycemic variability (β = −0.343, p = 0.016, β = 0.129, p = 0.017, respectively). Prolonged nocturnal wake duration was significantly associated with more time spent in daytime hypoglycemia (β = 0.037, p = 0.046) and higher overnight glycemic variability (J index, β = 0.300, p = 0.015). The associations between TST and glycemic variability indices were not significant. ConclusionsSleep quality rather than TST was significantly associated with glycemic variability in children with T1D. Eveningness preference might contribute to an increased risk of hypoglycemia. Addressing sleep patterns and chronotypes can be crucial in management plans for youth with T1D.

Chronotype and time-of-day effects on spatial working memory in preschool children.

Spatial working memory (SWM) capacity subserves complex cognitive functions, yet it is unclear whether individual diurnal preferences and time-of-day influence SWM in preschool children. The main and interaction effects of chronotype and time-of-day on SWM and SWM differences in preschoolers with different chronotypes within each time-of-day group will be examined. We studied a subset of typically developing 4.5-year-olds taking part in a birth cohort study (n = 359). The Children's Chronotype Questionnaire categorized children into morning-, intermediate-, and evening-types. Using a computerized neuropsychological test (Cambridge Neuropsychological Test Automated Battery), SWM was determined from the total number of between-search errors (ie, between search-total errors) and Strategy scores. Higher between search-total errors or lower Strategy scores indicated worse SWM. Time-of-day was categorized into late morning (10:00 am to 11:59 am), afternoon (12:00 pm to 3:59 pm), and late afternoon (4:00 pm to 6:30 pm). In a subsample (n = 199), caregiver-reported chronotype was validated using actigraphy-measured sleep midpoint. After controlling for ethnicity, no significant main and interaction effects of chronotype and time-of-day on between search-total errors and Strategy scores were seen (all P > .05). However, evening-types outperformed morning-types (ie, lower mean between search-total errors) in the late afternoon (P = .013) but not in the late morning and afternoon (all P > .05). Actigraphy data in the subsample confirmed that evening-types had later sleep midpoints during weekdays and weekends (P < .001). Since evening-type preschoolers had better SWM in the late afternoon compared to morning-type preschoolers, this gives insights into optimal learning opportunities in early childhood education. Abdul Jafar NK, Tham EKH, Eng DZH, etal. Chronotype and time-of-day effects on spatial working memory in preschool children. J Clin Sleep Med. 2023;19(10):1717-1726.

Associations of circadian factors with insomnia symptoms and emotional and behavioral problems among school-age children.

To examine the associations of circadian characteristics (ie, chronotype and social jetlag) with insomnia symptoms and emotional and behavioral problems among school-age children. A total of 620 primary school children (medianage = 10.06, standard deviation = 1.16, 58.7% boys) were recruited and assessed by a set of parent-report questionnaires, including Children's Sleep Habit Questionnaire for measuring sleep-wake patterns and insomnia symptoms (bedtime resistance, sleep onset delay, and night waking), Children's Chronotype Questionnaire for assessing the child's chronotype preference, and Strength and Difficulties Questionnaire for assessing emotional and behavioral problems. Linear regression models were applied to examine the associations of chronotype and social jetlag with insomnia symptoms and mental health outcomes, in which age, sex, family income, and average sleep duration were entered as covariates. Evening chronotype was significantly associated with bedtime resistance and sleep onset delay, while social jetlag was not related to insomnia symptoms. Evening chronotype was also significantly associated with externalizing symptoms after controlling for potential confounders. Evening chronotype, but not social jetlag, was the risk factor for insomnia symptoms, and evening chronotype was further associated with increased behavioral problems in school-age children. Our findings underscored the roles of circadian factors in relation to sleep and mental health problems in this young population. Sun W, Kwok NTT, Chan NY, etal. Associations of circadian factors with insomnia symptoms and emotional and behavioral problems among school-age children. J Clin Sleep Med. 2021;17(10):2107-2114.

Evaluation of the Relationship Between Attention Deficit Hyperactivity Disorder Symptoms and Chronotype.

The aim of the study is to investigate the relationship between circadian characteristics and behavioral problems in children with Attention Deficit Hyperactivity Disorder (ADHD) (n=53), and to compare this group with healthy controls (n=38). Fifty-three medication-free children with ADHD, aged 6-12 years, and 38 healthy children, age and sex matched, participated. Parents completed the Conners' Parent Rating Scale-Revised, the Children's Chronotype Questionnaire (CCTQ), and the Children's Sleep Habits Questionnaire (CSHQ) to assess sleep variables. ADHD children had more sleep-onset problems and parasomnias (in CSHQ) compared to healthy controls. However, circadian preferences did not differ between the groups in CCTQ scores. Another important finding was a mild correlation between parasomnia, bedtime on schooldays, and ADHD symptoms. Our study showed that children with ADHD showed more resistance to going to bed than did controls on school days. However, in contrast to our hypothesis, morningness/eveningness preference did not differ from controls in ADHD children.

The association between chronotype and sleep problems in preschool children

ObjectiveAdolescents and adults who are evening-types exhibit shorter sleep duration and more sleep problems than individuals with an earlier chronotype. We hypothesized that already at a preschool age, evening-types would exhibit more sleep problems relative to children who are morning or intermediate chronotypes. The aim of this study was to examine the association between chronotype and sleep problems among preschool children. MethodsWe studied a subset of typically-developing 4.5-year-olds taking part in the Growing Up in Singapore Towards healthy Outcomes birth cohort study (n = 244). The Children's Chronotype Questionnaire (CCTQ) was used to categorize children into morning-, intermediate-, and evening-types. Sleep problems were measured using the Children's Sleep Habits Questionnaire (CSHQ), with higher scores corresponding to greater sleep problems. The relation between chronotype, sleep–wake timing, and nocturnal sleep time was also evaluated in a subsample of 117 children using actigraphy recordings with parent-reported sleep diaries. ResultsAfter controlling for potential confounders (maternal education, child's sex, birth order, and ethnicity), a significant main effect of chronotype on sleep problems was observed, in which evening-types exhibited greater CSHQ scores compared to morning- and intermediate-types (all p < 0.001). Actigraphy data in the subsample confirmed that evening-types had later bedtimes (p < 0.001) and get-up times (p = 0.02) during weekdays and weekends, but shorter nocturnal sleep time (p = 0.034) only during weekdays, compared to children who had earlier chronotypes. ConclusionsIn preschool children, sleep problems were greater in evening-types compared to morning- and intermediate-types, suggesting that chronotype could be a contributing factor to sleep disturbances in early childhood.

Turkish Validation and Adaptation of Children ’s Chronotype Questionnaire (CCTQ)

Chronotype refers to the time of the day that a person's physical and cognitive functions are active. Simply this is a circadian phase preference of a person. While some of the people are morning active (so called larks) others are more active at nights (The owls). The study of circadian rhythms, known as chronobiology, is all about the metabolic and psychiatric differences between people who have different chronotypes. A few tests are used to determine chronotypes. The CCTQ (Children's Chronotype Questionnaire) is a parent-report, 27-item mixed format questionnaire measuring chronotype of children in multiple domains : the midsleep point on free days (MSF), a morningness/eveningness scale(M/E) score, and a five-point chronotype (CT) score. The aim of this study is adapting Children's Chronotype Questionnaire (CCTQ) into Turkish language and validating the instrument in Turkish population. 101 children aged nine through eighteen constitude the sample of the study. The sample was composed of clinical (n=51) and community groups (n=50). CCTQ and Morningness Eveningness Scale for Children (MESC) questionnaires were applied to children and parents, then the CCTQ and MESC scores were compared to examine the validity of CCTQ. The internal consistency and external validity of the Turkish CCTQ was sufficient to compare MESC-Turkish. As a result of this research carried out in accordance with methodological research principles, correlation between the M/E scores of CCTQ and MESC was significant. The Turkish version of CCTQ has been found to be valid and reliable in Turkish children.

P.7.f.001 Turkish validation and adaptation of Children's Chronotype Questionnaire (CCTQ)

P.7.f.001 Turkish validation and adaptation of Children's Chronotype Questionnaire (CCTQ)

The reliability and validity of the Japanese version of the Children's ChronoType Questionnaire (CCTQ) in preschool children

We aimed to examine the reliability and validity of the Japanese version of the Children's ChronoType Questionnaire (CCTQ) in preschool children. The CCTQ consists of 16 items on sleep–wake parameters for scheduled and free days, a 10-item of the Morningness/Eveningness Scale (CCTQ-M/E), and a single item on chronotype. Out of 502 children aged 3–6 years living in Okayama Prefecture, we evaluated 346 (188 boys and 158 girls) between May and June 2012. Their parents filled out the questionnaires two times at an interval of two weeks. Cronbach's α of the CCTQ-M/E was 0.77. For test–retest reliability, Pearson's correlation coefficient of the CCTQ-M/E between the two observations was 0.898 (p < 0.001). Kruskal–Wallis test with post-hoc tests was used to compare sleep–wake parameters measured with the CCTQ among the three groups of children, morning (M)-type, neither (N)-type and evening (E)-type, who were classified according to the CCTQ-M/E score. Sleep–wake parameters in timing were significantly different among the children with M-type, N-type and E-type (p < 0.001). Post-hoc pairwise comparisons revealed that sleep–wake parameters in timing were significantly delayed from the M-type to the N-type children (p < 0.001), from the M-type to the E-type children (p < 0.001), and from the N-type to the E-type children (p < 0.001), except that wake-up time and get-up time were not significantly different between the children with N-type and E-type on scheduled days when their start time was regularly fixed. Out of these 346 children, we evaluated 72 (35 boys and 37 girls) to see the correlations between subjectively and objectively measured sleep–wake parameters from June to October 2012. Spearman's correlation coefficients between sleep–wake parameters measured with the CCTQ and an actigraph were 0.512–0.836 on scheduled days (p < 0.001) and 0.380–0.786 on free days (p < 0.001). Based on these findings we conclude that the Japanese version of the CCTQ is a reliable and valid measure for assessing chronotypes in preschool children.

Chronotype is associated with the timing of the circadian clock and sleep in toddlers

Chronotype is a construct reflecting individual differences in diurnal preference. Although chronotype has been studied extensively in school-age children, adolescents and adults, data on young children are scarce. This study describes chronotype and its relationship to the timing of the circadian clock and sleep in 48 healthy children aged 30-36 months (33.4 ± 2.1 months; 24 males). Parents completed the Children's Chronotype Questionnaire (CCTQ) ~2 weeks before the start of the study. The CCTQ provides three measures of chronotype: midsleep time on free days, a multi-item morningness/eveningness score and a single item chronotype score. After 5 days of sleeping on their habitual schedule (assessed with actigraphy and sleep diaries), children participated in an in-home salivary dim light melatonin onset assessment. Average midsleep time on free days was 1:47 ± 0:35, and the average morningness/eveningness score was 26.8 ± 4.3. Most toddlers (58.4%) were rated as 'definitely a morning type' or 'rather morning than evening type', while none (0%) were rated as 'definitely evening type'. More morning types (midsleep time on free days and morningness/eveningness score, respectively) had earlier melatonin onset times (r = 0.45, r = 0.26), earlier habitual bedtimes (r = 0.78, r = 0.54), sleep onset times (r = 0.80, r = 0.52), sleep midpoint times (r = 0.90, r = 0.53) and wake times (r = 0.74, r = 0.34). Parent ratings using the single-item chronotype score were associated with melatonin onset (r = 0.32) and habitual bedtimes (r = 0.27), sleep onset times (r = 0.33) and sleep midpoint times (r = 0.27). Morningness may best characterize circadian preference in early childhood. Associations between chronotype and circadian physiology and sleep timing suggest adequate validity for the CCTQ in this age group. These findings have important implications for understanding the marked variability in sleep timing during the early years of life.

Assessment of Chronotype in Four- to Eleven-Year-Old Children: Reliability and Validity of the Children's ChronoType Questionnaire (CCTQ)

Individual differences in circadian phase preference (“chronotype”) are linked to sleep schedule variability, psychosocial functioning, and specific properties of the circadian clock. While much is known about the development, distribution, and variability of chronotype in adolescents and adults, assessment in prepubertal children has been hindered by a lack of appropriate, reliable, and valid measures. This study presents a detailed description of the assessment of children's chronotype by the Children's ChronoType Questionnaire (CCTQ). The CCTQ is a parent-report, 27-item mixed-format questionnaire resulting in multiple measures of chronotype in 4- to 11-yr-old children: the midsleep point on free days (MSF), a morningness/eveningness scale (M/E) score, and a five-point chronotype (CT) score. The study provides validity data using actigraphy as well as test-retest reliability data for all three chronotype measures and sleep/wake parameters. Overall, the findings indicate moderate to strong agreement between the three measures, adequate associations between chronotype measures and sleep/wake parameters assessed by actigraphy, and excellent temporal stability (reliability).