Article
Clinical Neurology
Stephen P. Becker, Aaron M. Luebbe, Michael J. Kofler, G. Leonard Burns, Matthew A. Jarrett
Summary: This study found that college students with attention-deficit/hyperactivity disorder (ADHD) symptoms are more likely to have an evening chronotype. In particular, symptoms of inattention are strongly associated with a preference for later circadian rhythms.
JOURNAL OF SLEEP RESEARCH
(2023)
Article
Multidisciplinary Sciences
Julieta Castillo, Andre C. Tonon, Maria Paz Hidalgo, Ana Silva, Bettina Tassino
Summary: A trip to the Antarctic summer allowed researchers to explore the impact of increased light exposure on circadian rhythms and sleep patterns. The study found that the effect of light on the circadian system depends on the time it is received, and individual circadian phase shift is influenced by past exposure to light.
SCIENTIFIC REPORTS
(2023)
Article
Multidisciplinary Sciences
Peter P. Ujma, Csenge G. Horvath, Robert Bodizs
Summary: A survey of Hungarian adults found that the timing of daily activity is influenced by demographic and health-related factors such as age, sex, and socioeconomic status. The study also identified social jetlag and certain disorders as being associated with an individual's chronotype, while no causal relationship was found between light exposure and mental health.
SCIENTIFIC REPORTS
(2023)
Article
Multidisciplinary Sciences
C. Papatsimpa, L. J. M. Schlangen, K. C. H. J. Smolders, J-P M. G. Linnartz, Y. A. W. de Kort
Summary: Individuals differ in their timing of sleep and daytime activities, defining the "chronotype"; Spending time in relatively dim light conditions during the day leads to a later biological clock and increased interindividual differences in circadian phase; Increasing daytime illuminance results in a narrower distribution of sleep timing and circadian phase.
SCIENTIFIC REPORTS
(2021)
Article
Multidisciplinary Sciences
Melissa A. St Hilaire, Maria L. Amundadottir, Shadab A. Rahman, Shantha M. W. Rajaratnam, Melanie Ruger, George C. Brainard, Charles A. Czeisler, Marilyne Andersen, Joshua J. Gooley, Steven W. Lockley
Summary: This study investigates the contributions of different wavelengths of monochromatic light to human melatonin suppression and circadian resetting responses. The results show that, initially, short-wavelength (S) cones and long- and medium-wavelength (L+M) cones have a significant contribution, while the contribution of melanopsin-containing intrinsically-photosensitive retinal ganglion cells (ipRGCs) becomes dominant over time. The first few minutes of light exposure play a crucial role in the phase resetting response.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Multidisciplinary Sciences
C. Tortello, A. Folgueira, J. M. Lopez, F. Didier Garnham, E. Sala Lozano, M. S. Rivero, G. Simonelli, D. E. Vigo, S. A. Plano
Summary: This study aimed to investigate the influence of external zeitgebers on chronotype and sleep during a winter campaign at the Argentine Antarctic station. The main findings showed a decrease in sleep duration and a delay in chronotype and social jetlag during the polar night, indicating the impact of social cues and lack of natural light on circadian rhythms.
SCIENTIFIC REPORTS
(2023)
Article
Psychiatry
Magdalena Linke, Konrad S. Jankowski
Summary: Research indicates that individuals with schizophrenia tend to have a more evening chronotype compared to healthy controls, but similar to those with bipolar I disorder. This suggests that eveningness might be a marker for mental health issues in general, beyond just mood disorders.
SCHIZOPHRENIA RESEARCH
(2021)
Article
Education & Educational Research
Guadalupe Rodriguez Ferrante, Andrea P. Goldin, Mariano Sigman, Maria Juliana Leone
Summary: Schools around the world start early in the morning, which conflicts with the late sleep patterns of adolescents. Surprisingly, students with later sleep patterns tend to have lower academic performance. However, it is unclear whether this is due to the direct effect of sleep patterns or because students have to attend school too early. Furthermore, there is limited understanding of how this affects students' academic success beyond their grades. To address this gap, we conducted a study to examine how school timing and sleep patterns impact grade retention in a unique sample of students with different school schedules. Even after controlling for academic performance, we found that students with later sleep patterns have a higher likelihood of grade retention only when their classes start in the morning, but not in later school timings. Overall, aligning school timing with students' biological rhythms could enhance future opportunities for adolescents.
NPJ SCIENCE OF LEARNING
(2023)
Review
Endocrinology & Metabolism
Rui Zhang, Xiaoling Cai, Chu Lin, Wenjia Yang, Fang Lv, Jing Wu, Linong Ji
Summary: This study evaluated the association between evening chronotype and social jetlag (SJL) with obesity, blood glucose, and lipid levels in non-shift working adults. The results showed that evening chronotype and large SJL were associated with obesity and unfavorable metabolic parameters.
FRONTIERS IN ENDOCRINOLOGY
(2022)
Review
Biology
Vanessa F. Vidueira, Josie N. Booth, David H. Saunders, John Sproule, Anthony P. Turner
Summary: Adolescence is a crucial period of development, and changes in circadian rhythmicity have a significant impact on the performance of adolescents. Studies have shown that morning type adolescents tend to outperform evening types in academic achievement, and performance in tests of intelligence and executive functions is generally better at optimal times of the day. However, there are still many factors that need further investigation in understanding the relationship between chronotype and performance in adolescents.
CHRONOBIOLOGY INTERNATIONAL
(2023)
Article
Biology
Daniel S. Joyce, Manuel Spitschan, Jamie M. Zeitzer
Summary: This study investigates the sensitivity of the human circadian system to flashed light, finding a dose-response relationship between flash intensity and circadian phase shift, and a slight parametric relationship between flash duration and circadian phase shift.
PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES
(2022)
Article
Biology
Daniel S. S. Joyce, Manuel Spitschan, Jamie M. M. Zeitzer
Summary: In this study, the impact of different durations of light flash sequences on the human circadian pacemaker was examined. It was found that 15 minutes of light flashes can have a similar effect on circadian timing as 3.5 hours of light flashes. The retinohypothalamic circuit responsible for shifting the timing of the circadian pacemaker becomes refractory to further stimulation after the first 15 minutes of exposure.
Article
Multidisciplinary Sciences
Katarzyna Burek, Sylvia Rabstein, Thomas Kantermann, Celine Vetter, Markus Rotter, Rui Wang-Sattler, Martin Lehnert, Dirk Pallapies, Karl-Heinz Joeckel, Thomas Bruening, Thomas Behrens
Summary: This study examined the impact of night shift on salivary cortisol levels at awakening and the cortisol awakening response (CAR). The results showed that shift workers had lower cortisol levels at awakening before day shifts and lower CARs after night shifts compared to non-shift workers. This effect was most pronounced in early chronotypes.
SCIENTIFIC REPORTS
(2022)
Article
Clinical Neurology
David R. Colelli, Gio R. Dela Cruz, Tetyana Kendzerska, Brian J. Murray, Mark I. Boulos
Summary: People's sleep patterns, known as chronotypes, are associated with their sleep quality and duration. Morning types tend to have better sleep quality and longer sleep duration, while evening types experience poorer sleep quality. Therefore, laboratory protocols should consider individuals' chronotypes when evaluating sleep.
JOURNAL OF SLEEP RESEARCH
(2023)
Article
Biology
Hakan Ogutlu, Sabide Duygu Uygun, Christoph Randler
Summary: The study evaluated the psychometric properties of the Turkish version of the Morningness-Eveningness Stability Scale (MESSi) in adolescents, showing its validity and reliability in this age group, and its associations with personality, affect, and sleep quality. The three-factor MESSi demonstrated an advantage over other chronotype scales in adolescence, as it includes a Delayed Sleep Phase (DI) subscales in addition to the Morningness (MA) and Eveningness (EV) subscales.
CHRONOBIOLOGY INTERNATIONAL
(2021)