Sleep, intelligence and cognition in a developmental context: differentiation between traits and state-dependent aspects

Association between personality characteristics and sleep quality among Chinese middle-aged and older adults: evidence from China family panel studies

BACKGROUND

Poor sleep quality will have adverse effects on physical and mental health, quality of life and other aspects of middle-aged and older adults. Sleep quality is affected by many factors. Whether the sleep quality measures of the participants had changed in the previous or subsequent time period is not easily taken into account. Moreover, there have been no studies on this topic in Chinese middle-aged and older adults. The objective of this study was to mitigate the bias of sleep quality assessment, and analyze the association between personality traits and sleep quality in Chinese middle-aged and older adults.

METHODS

The data came from the China Family Panel Studies (CFPS). A total of 6031 participants aged ≥ 45 years were included in this study. Personality characteristics were evaluated based on the scores of each dimension of Big Five personality traits. Sleep duration and sleep perception were used as indicators to measure sleep quality. Logistic models were used to analyze the relationship between personality traits and sleep duration or sleep perception, respectively.

RESULTS

4.5% of the participants had abnormal sleep duration, and 14.4% had a pessimistic sleep perception. Conscientiousness was rated the highest among the personality traits (3.97 ± 0.6). Participants with higher scores for extraversion personality traits had more normal sleep duration (OR = 0.77, 95% CI: 0.64-0.93) and more optimistic sleep perception (OR = 0.86, 95% CI: 0.76-0.96). Using the Internet and feeling unwell in the past week have a moderating effect on the impact of conscientiousness personality characteristics on sleep duration or sleep perception, respectively (but not overall sleep quality). In addition, participants with a spouse or no recent physical discomfort tended to have a normal sleep duration and a more optimistic sleep perception.

CONCLUSIONS

The higher the score of extraversion personality traits, the better the overall sleep quality of middle-aged and older adults. Having a spouse and feeling unwell were the important factors affecting their sleep quality. Specific personality traits intervention should be carried out for middle-aged and older adults with poor sleep quality to make their personality traits are closer to extraversion. In addition, middle-aged and older adults without spouses should be encouraged to marry or remarry. We will strengthen health management and medical expenditures for middle-aged and older adults.

The relation between sleep and neurocognitive development in infancy and early childhood: A neuroscience perspective

Sleep is essential for human life. It has different characteristics in the early stages of life compared to later periods: during development, qualitative and quantitative changes in sleep features occur such as the onset of REM/NREM sleep at 3 months, the progressive increase of night sleep duration, and the reduction of total sleep time. Sleep seems to be essential in the cognitive functions' development, especially in the first period of life. Indeed, higher rates of night sleep at the age of 12 and 18 months are associated with higher executive functions' performance. Furthermore, memory consolidation occurs during sleep and sleep contributes to children's learning not only in retaining information but also in organizing memories most efficiently. Therefore, sleep problems could cause negative effects on some features of cognitive development like memory, executive functions, and learning process. There is also an intimate relationship between sleep and regulation of emotional brain functions, with a link between sleep disturbance and behavioral problems.

Systematic Review of Sleep Disturbances and Circadian Sleep Desynchronization in Autism Spectrum Disorder: Toward an Integrative Model of a Self-Reinforcing Loop

Background: A compelling number of studies, conducted in both children and adults, have reported an association between sleep disturbances/circadian sleep alterations and autism spectrum disorder (ASD); however, the data are sparse and the nature of this link is still unclear. The present review aimed to systematically collect the literature data relevant on sleep disturbances and circadian sleep dysrhythmicity related to ASD across all ages and to provide an integrative theoretical framework of their association. Methods: A systematic review of the MEDLINE, PubMed, and Cochrane databases was conducted from November 2018 to February 2019. The search strategies used were MeSH headings and keywords for "sleep-wake circadian rhythms" OR "circadian sleep disorders" OR "sleep-wake pattern" OR "sleep disorders" OR "melatonin" AND "autism spectrum disorder" OR "autism". Results: One hundred and three studies were identified, 15 regarded circadian sleep dysrhythmicity, 74 regarded sleep disturbances, and 17 regarded melatonin alterations in children and adults with ASD. Our findings suggested that autistic subjects frequently present sleep disturbances in particular short sleep duration, low sleep quality/efficiency, and circadian sleep desynchronization such as delayed phases and/or eveningness. Sleep disturbances and circadian sleep alterations have been related to the severity of autistic symptoms. Genetic studies have shown polymorphisms in circadian CLOCK genes and in genes involved in melatonin pathways in subjects with ASD. Conclusions: Sleep disturbances and circadian sleep alterations are frequent in subjects with autistic symptoms. These subjects have shown polymorphisms in clock genes expression and in genes involved in melatonin production. The impairment of circadian sleep regulation may increase the individual's vulnerability to develop symptoms of ASD by altering the sleep regulation in toto, which plays a key role in normal brain development. Even though controversies and "research gaps" are present in literature at this point, we may hypothesize a bidirectional relation between circadian sleep dysfunction and ASD. In particular, circadian sleep dysrhythmicity may predispose to develop ASD symptoms and vice versa within a self-reinforcing feedback loop. By targeting sleep disturbances and circadian sleep dysrhythmicity, we may improve treatment strategies for both children and adults with ASD.

Sleep Disordered Breathing and Academic Performance: A Meta-analysis

BACKGROUND AND OBJECTIVE

Sleep-disordered breathing (SDB) in children is associated with daytime functioning decrements in cognitive performance and behavioral regulation. Studies addressing academic achievement are underrepresented. This study aimed to evaluate the strength of the relationships between SDB and achievement in core domains and general school performance.

METHODS

Data sources included PubMed, Web of Science, CINAHL, and PsycINFO. Studies of school-aged children investigating the relationships between SDB and academic achievement were selected for inclusion in a systematic literature review using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Data extracted were converted into standardized mean differences; effect sizes (ES) and statistics were calculated by using random-effects models. Heterogeneity tests (I(2)) were conducted.

RESULTS

Of 488 studies, 16 met eligibility criteria. SDB was significantly associated with poorer academic performance for core academic domains related to language arts (ES -0.31; P < .001; I(2) = 74%), math (ES -0.33; P < .001; I(2) = 55%), and science (ES -0.29; P = .001; I(2) = 0%), and with unsatisfactory progress/learning problems (ES -0.23; P < .001; I(2) = 0%) but not general school performance.

CONCLUSIONS

Variable definitions of both academic performance and SDB likely contributed to the heterogeneity among published investigations. Clear links between SDB and poorer academic performance in school-age children are demonstrated. ES statistics were in the small to medium range, but nevertheless the findings serve to highlight to parents, teachers, and clinicians that SDB in children may contribute to academic difficulties some children face.