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Journal: Sleep


To examine the association between sleep duration trajectories over 28 years and measures of cognition, gray matter volume, and white matter microstructure. We hypothesize that consistently meeting sleep guidelines that recommend at least 7 hours of sleep per night will be associated with better cognition, greater gray matter volumes, higher fractional anisotropy, and lower radial diffusivity values.


We examined the night-to-night associations of evening use of alcohol, caffeine, and nicotine with actigraphically estimated sleep duration, sleep efficiency, and wake after sleep onset (WASO) among a large cohort of African American adults.


To examine the changes in mothers' and fathers' sleep satisfaction and sleep duration across pre-pregnancy, pregnancy, and the postpartum period of up to six years after birth; it also sought to determine potential protective and risk factors for sleep during that time.


Most people will at some point experience not getting enough sleep over a period of days, weeks, or months. However, the effects of this kind of everyday sleep restriction on high-level cognitive abilities - such as the ability to store and recall information in memory, solve problems, and communicate - remain poorly understood. In a global sample of over 10,000 people, we demonstrated that cognitive performance, measured using a set of 12 well-established tests, is impaired in people who reported typically sleeping less, or more, than 7-8 hours per night - which was roughly half the sample. Crucially, performance was not impaired evenly across all cognitive domains. Typical sleep duration had no bearing on short-term memory performance, unlike reasoning and verbal skills, which were impaired by too little, or too much, sleep. In terms of overall cognition, a self-reported typical sleep duration of 4 hours per night was equivalent to aging 8 years. Also, sleeping more than usual the night before testing (closer to the optimal amount) was associated with better performance, suggesting that a single night’s sleep can benefit cognition. The relationship between sleep and cognition was invariant with respect to age, suggesting that the optimal amount sleep is similar for all adult age groups, and that sleep-related impairments in cognition affect all ages equally. These findings have significant real-world implications, because many people, including those in positions of responsibility, operate on very little sleep and may suffer from impaired reasoning, problem-solving, and communications skills on a daily basis.


To investigate the short- and longer-term impact of a 45-min delay in school start time on sleep and well-being of adolescents.

Concepts: Delay


To determine if weekend catch-up sleep (CUS) impacts body mass index (BMI) in the general population.

Concepts: Mass, Body mass index, Body weight


The high prevalence of chronic insufficient sleep in the population has been a concern due to the associated health and safety risks. We evaluated secular trends in sleep duration over the most recent 14-year period.

Concepts: United States, Poverty in the United States, U.S. state, Occupational safety and health


To assess the prospective relationship between sleep and obesity in a paediatric population.


Nightmares are a frequent symptom in narcolepsy. Lucid dreaming, i.e., the phenomenon of becoming aware of the dreaming state during dreaming, has been demonstrated to be of therapeutic value for recurrent nightmares. Data on lucid dreaming in narcolepsy patients, however, is sparse. The aim of this study was to evaluate the frequency of recalled dreams (DF), nightmares (NF), and lucid dreams (LDF) in narcolepsy patients compared to healthy controls. In addition, we explored if dream lucidity provides relief during nightmares in narcolepsy patients.

Concepts: Hallucination, Personal life, Dream, Dream journal, Dreaming, Lucid dream, False awakening, The Sandman


To investigate the restorative quality of sleep and daytime functioning in sleepwalking adult patients in comparison with controls.

Concepts: Case-control study