Both evening chronotype and shift work are associated with depressive symptoms. This study examined whether the association between mood disorders sleep problems varies by chronotype. The population included 10637 participants from Finnish Hospital Personnel Cohort Study. Work schedule was assessed using repeated questionnaires 2000 2017. Chronotype, a single item Diurnal Type Scale, categorize...

• Morning chronotype is highly related to higher inter-daily stability ( i.e., the strength of circadian synchronization). Overall, evening types have superior verbal abilities which contradicts conventional wisdom that “the early bird gets worm”. However, i.e. , more morning) MEQ scores were after controlling for “bedtime” behaviours. Chronotype impacts our state at a given time day, however, ...

Abstract Objectives The present study investigated the relationships between sleep (sleep duration and need for additional time in morning), chronotype, work-related stress, negative affect daytime workers. Furthermore, it was examined whether a flexible start of work moderates these relationships. Methods A cross-sectional online conducted. Participants were 438 (247 female) workers 18 73 year...

Although peaks and troughs in cognitive performance characterize our daily functioning, time-of-day fluctuations remain marginally considered in the domain of cognitive psychology and neuropsychology. Here, we attempt to summarize studies looking at the effects of sleep pressure, circadian variations, and chronotype on cognitive functioning in healthy subjects. The picture that emerges from thi...

The role of endogenous melatonin for the control of the circadian system under entrained conditions and for the determination of the chronotype is still poorly understood. Mice with deletions in the melatoninergic system (melatonin deficiency or the lack of melatonin receptors, respectively) do not display any obvious defects in either their spontaneous (circadian) or entrained (diurnal) rhythm...

In this study (N = 263) we provide a basic test of a niche-specialization hypothesis of the Dark Triad (i.e., narcissism, psychopathy, and Machiavellianism). We propose that in order to best enact a ‘‘cheater strategy’’ those high on the Dark Triad traits should have optimal cognitive performance and, thus, have a night-time chronotype. Such a disposition will take advantage of the low light, t...

We report on results from an Internet survey of sleeping habits in a Dutch population using the Munich Chronotype Questionnaire (MCTQ), supplemented with the Horne-Ostberg Morningness-Eveningness Questionnaire (MEQ). The MCTQ was completed by 5,055 responders, of which 2,481 also completed the MEQ. MEQ score correlated well with the MCTQ assessment of time of mid-sleep on free days (MSF; r = - ...

Chronotype and cognitive ability are two human phenotypes with an uneven geographic distribution due to both selective migration causal environmental effects. In our study, we aimed examine the relationship between variables, chronotype. We used a large anonymized sample (n = 25,700, mostly from USA, UK, Canada Australia) of dating site users estimate chronotype questionnaire responses using it...

BACKGROUND Shift work-related carcinogenesis is hypothesized to be mediated by melatonin; however, few studies have considered the potential effect modification of this underlying pathway by chronotype or specific aspects of shift work such as the number of consecutive nights in a rotation. In this study, we examined melatonin patterns in relation to shift status, stratified by chronotype and n...