Previous research found that personality and chronotype both are significant predictors of alcohol consumption. This study examined the personality type neuroticism and the evening chronotype as...Show morePrevious research found that personality and chronotype both are significant predictors of alcohol consumption. This study examined the personality type neuroticism and the evening chronotype as possible correlates of increased alcohol consumption. Additionally, we aimed to find a moderating effect of eveningness in the relationship between neuroticism and alcohol consumption. The Netherlands Study of Depression and Anxiety (NESDA) included 2,981 participants between the ages of 18 and 65 and a total of more than eight questionnaires, from which we used the Munich Chronotype Questionnaire (MCTQ), Alcohol Use Disorder Identification Test (AUDIT) and Neuroticism-Extraversion-Openness Five-Factor Inventory (NEO-FFI). Results showed a significant association between eveningness and alcohol consumption. The predicted moderation effect of eveningness was not found. The findings of this study may give a better understanding of possible risk factors for increased alcohol consumption, by verifying the predicted association between eveningness and increased alcohol consumption. Future research may however look further into the working mechanisms of eveningness with respect to the susceptibility of increased alcohol consumption.Show less
The change to daylight saving time (DST) not only provides us with more excess to daylight but it also causes energy savings for half a year. Nevertheless, not everyone experiences the change to...Show moreThe change to daylight saving time (DST) not only provides us with more excess to daylight but it also causes energy savings for half a year. Nevertheless, not everyone experiences the change to DST as pleasant. The human sleep- wake rhythm does not seem to synchronize well when changing to DST. An unsynchronized rhythm causes sleep disruptions and other negative health effects. To ensure human health, there is need for a solution. On one hand, it might be an idea to either abolish or adjust the change to DST. On the other hand, the group of people experiencing issues with the change to DST might be relatively small for this solution to be successful. To contribute to this discussion, the current study has been performed. This study focusses on the influence of chronotype on the change to DST. Chronotype has been proven to explain differences in sleep wake rhythms between individuals. The main research question was as follows: What is the effect of the change to DST on the sleep wake rhythm of morning and evening chronotypes? The findings of the current study show that both morning and evening chronotypes suffer from the change to DST regarding their time of wakening. However, a change in bedtime only occurred for evening chronotypes. In conclusion, since both morning and evening chronotypes experience disruptions due to the change to DST, it might be relevant to reconsider other solutions related to this change.Show less
Approximately ten to thirty percent of the children don’t get enough sleep. This can cause problems with learning and cognition. Evening-types often experience more sleep problems than morning...Show moreApproximately ten to thirty percent of the children don’t get enough sleep. This can cause problems with learning and cognition. Evening-types often experience more sleep problems than morning-types. This study investigates the relationship between chronotype and cognitive performances (sustained attention, inhibition and working memory) and whether this relationship is mediated by sleep duration. The sample consisted 452 children (208 males and 244 females; mean age 10.49 years). Parents filled in the Children’s Chronotype Questionnaire to measure chronotype. They also filled in a sleeping diary for a week to measure sleep duration. The children made multiple computer tasks: the Psychomotor Vigilance Task (PVT) to measure sustained attention, the PVT Go/No-Go to measure inhibition and a Digit Span task to measure working memory. Eveningness was associated with less sleep (β = -.10). Second, sustained attention and inhibition were not associated with chronotype. Evening-types performed better on the working memory task (β = .10). Third, children with less sleep performed better on the sustained attention (β = .16) and working memory task (β = -.25), but worse on the inhibition task (β = .12). This results show that sleep duration did not mediated the relation between chronotype and sustained attention and inhibition. But the relationship between chronotype and working memory is partially mediated by sleep duration. Evening-types remember a longer string of numbers than morning-types, this can be partially explained because the evening-types sleep shorter. It is important to investigate why these children perform better, despite the shorter sleep duration. Maybe sleep quality has a bigger influence on the cognitive performances than sleep duration. Last, it is important for parents to realize that sleep is important for the development of their children, because prevention is better than intervention.Show less
Het doel van dit onderzoek was om te onderzoeken of er een relatie bestaat tussen avondlijkheid en gedragsproblemen bij kinderen. Hierbij is nader onderzoek verricht in de samenhang van deze...Show moreHet doel van dit onderzoek was om te onderzoeken of er een relatie bestaat tussen avondlijkheid en gedragsproblemen bij kinderen. Hierbij is nader onderzoek verricht in de samenhang van deze relatie met betrekking tot puberteit, temperament en slaapduur. De volgende vraag stond centraal in dit onderzoek: “Is er een relatie tussen avondlijkheid en internaliserende en externaliserende gedragsproblemen bij kinderen in de leeftijd van 9 tot en met 11 jaar?” Aan dit onderzoek hebben in totaal 97 kinderen deelgenomen. Hiervan zijn 44 jongens en 53 meisjes in de leeftijd van 9 tot 12 jaar (M = 10.51, SD = .79). Met behulp van de Children’s Chronotype Questionnaire (CCTQ) is het chronotype van de participanten gemeten. De Strengths and Difficulties Questionnaire (SDQ) is gebruikt om de internaliserende en externaliserende gedragsproblemen te bepalen. De puberale status van de kinderen is gemeten met de Puberty Development Scale (PDS) en het temperament met de Early Adolescent Temperament Questionnaire-Revised (EATQ-R). Een logboek ingevuld door ouders gedurende zeven achtereenvolgende dagen, is gebruikt om de slaapduur van de kinderen bij te houden. In het onderzoek is geen relatie gevonden tussen avondlijkheid en gedragsproblemen. Ook met betrekking tot de factoren puberteit en temperament is er geen samenhang gevonden. Tussen avondlijkheid en slaapduur is wel een relatie gevonden. Het betreft een negatieve relatie, wat inhoudt dat naarmate de kinderen hoger scoren op avondlijkheid zij een kortere slaapduur hebben. Er is verder onderzoek nodig om de relatie tussen chronotype en gedragsproblemen in kaart te brengen.Show less
The transition to adolescence is linked to behavioral and/or emotional problems, and to a change of circadian phase preference towards evening chronotype. Recent studies showed that eveningness in...Show moreThe transition to adolescence is linked to behavioral and/or emotional problems, and to a change of circadian phase preference towards evening chronotype. Recent studies showed that eveningness in adolescence is associated with behavioral and emotional problems and with shorter sleep duration, poor sleep quality, and daytime sleepiness. Studies on chronotype, sleep and behavioral/emotional problems in preadolescents are scarce. The current study examined: 1) whether there is association between chronotype and behavioral/ emotional problems in healthy 9, 10, and 11-year-old preadolescents, and 2) whether the hypothesized correlation is mediated by sleep quality, sleepiness, and/or sleep duration. Parents of 98 Dutch children aged 9 to 11 filled out the Strengths and Difficulties Questionnaire (SDQ), Children’s Chronotype Questionnaire (CCTQ), Sleep Disturbance Scale for Children (SDSC), and a sleep diary. The hypothesized association between eveningness and behavioral and/or emotional problems was not found. However, eveningness was significantly correlated to poor sleep quality and daytime sleepiness. Furthermore, poor sleep quality was significantly correlated to externalizing problems, and daytime sleepiness was significantly correlated to internalizing problems. To conclude, eveningness does not increase the risk of behavioral/emotional problems, but is related to poor sleep quality and increased daytime sleepiness. These results suggest that evening types are particularly vulnerable to behavioral/emotional problems when they experience poor sleep quality/ daytime sleepiness. Moreover it might mean that other children, who are not considered evening types but do experience poor sleep quality/daytime sleepiness, may also be vulnerable to behavioral/emotional problems.Show less
With a prevalence of 25% - 40%, sleep disturbances are a common problem among youths. Research in adolescents and adults shows correlation between sleep problems and chronotype(individual...Show moreWith a prevalence of 25% - 40%, sleep disturbances are a common problem among youths. Research in adolescents and adults shows correlation between sleep problems and chronotype(individual differences in circadian phase preference, e.g. eveningness), with more eveningness relating to higher reports of sleep problems. However, less is known about this relationship in children. This study investigates the association between children’s chronotype(morning, intermediate, evening type) and sleep duration as well as sleep disturbances as reported by parents. Data has been collected in 9 to 12 year old children (n = 98) using the Children’s Chronotype Questionnaire (CCTQ), the Sleep Disturbance Scale for Children (SDSC) and a 7-nights sleep diary. The analyses show that evening types (n = 15, M = 47.47) have significant more sleep problems than intermediate (n= 27, M = 39.11), p = .003 or morning types (n = 27, M = 35.70), p < .01. To be more specific, evening types have more problems with initiating and maintaining sleep (p < .01) and more excessive daytime somnolence (p < .01). No significant difference has been found between chronotypes in sleep duration. The main conclusion is that evening types among children have a higher risk of sleep problems, although sleep duration is similar to that in other chronotypes. This knowledge confirms the important role of chronotype and implicates that more focus on the characteristics of chronotypes is necessary in the clinical field.Show less
Sleep duration and chronotype are known to have an influence on inhibitory control in adolescents. To date, there are no studies that have looked into this relationship in in school age children ....Show moreSleep duration and chronotype are known to have an influence on inhibitory control in adolescents. To date, there are no studies that have looked into this relationship in in school age children . The question in this research is, is the relationship between chronotype and inhibition mediated by sleep duration in children between the age of 9 and 11 years old? The sample included 594 children between 9 and 11 years old (M=10.48, SD=.82). There were 227 boys and 263 girls (from 104 children gender was unknown). Three instruments have been used; the first instrument was the Children's ChronoType Questionnaire (CCTQ). This questionnaire measures whether the child would a morning type or an evening type. The second instrument was a sleep diary. This sleep diary measures different elements of sleep, for this study the average sleep duration was used. The last instrument that was used, was the inhibition Psychomotor Vigilance Task GoNogo (PVT GoNogo). This instrument measures inhibition with the percentage of correct Nogo's. In this study, chronotype did not serve as a significant predictor for inhibition. In addition, chronotype did not serve as a significant predictor for sleep duration. However, sleep duration did serve as a significant predictor for inhibition (β =.12, t(459) = 2.48, p =.014). Longer duration of sleep was correlated to better inhibition. There was no evidence for sleep duration as a mediator between chronotype and inhibition in children between the age of 9 and 11 years old. Information on the influence of sleep on inhibition problems can be valuable to both professionals and parents. Sleeping problems should also be considered, when there are inhibition problems.Show less
Samenvatting Introductie: Het avondchronotype is in eerdere onderzoeken geassocieerd met verminderd cognitief functioneren, slaaptekort en gedrags-emotionele problematiek. In dit onderzoek zal...Show moreSamenvatting Introductie: Het avondchronotype is in eerdere onderzoeken geassocieerd met verminderd cognitief functioneren, slaaptekort en gedrags-emotionele problematiek. In dit onderzoek zal gefocust worden op het laatste, namelijk gedragsproblemen en de relatie met het chronotype. De onderzoeksvragen zijn: 1) Is er bij kinderen met een avondchronotype sprake van hogere scores op internaliserende en externaliserende gedragsproblematiek dan bij kinderen met een ochtendchronotype? 2) Wordt een eventuele relatie tussen chronotype en gedrags/emotionele problemen gemedieerd door een verminderde slaapduur? Methoden: De onderzoeksgroep die in dit onderzoek wordt gebruikt, bestaat uit 333 kinderen, waarvan 149 jongens en 184 meisjes in de leeftijd van 7 tot 12 jaar van verschillende scholen door heel Nederland. Ouders vulden vragenlijsten in over chronotype (CCTQ), gedragsproblemen (CBCL) en slaapgewoonten, waaronder slaapduur (Slaapgewoontes van het kind). Resultaten: Uit de resultaten blijkt dat er een groot verschil bestaat tussen de ochtend- en neutrale types en de avondtypes. De mogelijke verklaring hiervoor zou het aantal uren slaap zijn. Uit de mediatieanalyse komt naar voren dat er geen sprake is van mediatie. Conclusie: De conclusie van dit onderzoek is dat avondtypes meer gedragsproblemen vertonen dan ochtend- of neutrale types. Het aantal uren slaap lijkt hier geen rol in te spelen.Show less
