Delayed melatonin circadian timing, lower melatonin output, and sleep disruptions in myopic, or short-sighted, children.

Study Objectives: This study investigated the differences in melatonin circadian timing and output, sleep characteristics, and cognitive function in myopic and non-myopic (or emmetropic) children, aged 8-15 years.

Methods: Twenty-six myopes (refractive error [mean ± standard error mean] -2.06 ± 0.

Circadian aspects in the aetiology and pathophysiology of insomnia.

Because the endogenous circadian pacemaker is a very strong determinant of alertness/sleep propensity across the 24 h period, its mistiming may contribute to symptoms of insomnia (e.g., difficulties initiating sleep and maintaining sleep) and to the development of insomnia disorder.

Electric lighting, adolescent sleep and circadian outcomes, and recommendations for improving light health.

Light is a potent circadian entraining agent. For many people, daily light exposure is fundamentally dysregulated with reduced light during the day and increased light into the late evening. This lighting schedule promotes chronic disruption to circadian physiology resulting in a myriad of impairments.

Light-based methods for predicting circadian phase in delayed sleep-wake phase disorder.

Methods for predicting circadian phase have been developed for healthy individuals. It is unknown whether these methods generalize to clinical populations, such as delayed sleep-wake phase disorder (DSWPD), where circadian timing is associated with functional outcomes. This study evaluated two methods for predicting dim light melatonin onset (DLMO) in 154 DSWPD patients using ~ 7 days of sleep-wake and light data: a dynamic model and a statistical model.

Myopia, or near-sightedness, is associated with delayed melatonin circadian timing and lower melatonin output in young adult humans.

Study Objectives: Myopia, or near-sightedness, is the most common refractive vision disorder and predisposes the eye to many blinding conditions in adulthood. Recent research has suggested that myopia is associated with increased endogenous melatonin production. Here we investigated the differences in melatonin circadian timing and output in young adult myopes and non-myopes (or emmetropes) as a pathogenesis for myopia.

A PERIOD3 variable number tandem repeat polymorphism modulates melatonin treatment response in delayed sleep-wake phase disorder.

We examined whether a polymorphism of the PERIOD3 gene (PER3; rs57875989) modulated the sleep-promoting effects of melatonin in Delayed Sleep-Wake Phase Disorder (DSWPD). One hundred and four individuals (53 males; 29.4 ±10.

Sleep regularity is associated with sleep-wake and circadian timing, and mediates daytime function in Delayed Sleep-Wake Phase Disorder.

Background: In healthy populations, irregular sleep patterns are associated with delayed sleep and poor functional/mood outcomes. Currently, it is unknown whether irregular sleep contributes to poor functional/mood outcomes in individuals with Delayed Sleep-Wake Phase Disorder (DSWPD).

Methods: In 170 patients with DSWPD, we collected sleep-wake patterns, dim light melatonin onset (DLMO), and functional/mood outcomes.

Increased sensitivity of the circadian system to light in delayed sleep-wake phase disorder.

Key Points: This is the first study to demonstrate an altered circadian phase shifting response in a circadian rhythm sleep disorder. Patients with delayed sleep-wake phase disorder (DSWPD) demonstrate greater sensitivity of the circadian system to the phase-delaying effects of light. Increased circadian sensitivity to light is associated with later circadian timing within both control and DSWPD groups.

Prevalence of Circadian Misalignment and Its Association With Depressive Symptoms in Delayed Sleep Phase Disorder.

Study Objective: To examine the prevalence of circadian misalignment in clinically diagnosed delayed sleep phase disorder (DSPD) and to compare mood and daytime functioning in those with and without a circadian basis for the disorder.

Methods: One hundred and eighty-two DSPD patients aged 16-64 years, engaged in regular employment or school, underwent sleep-wake monitoring in the home, followed by a sleep laboratory visit for assessment of salivary dim light melatonin onset (DLMO). Based on the DLMO assessments, patients were classified into two groups: circadian DSPD, defined as DLMO occurring at or after desired bedtime (DBT), or non-circadian DSPD, defined as DLMO occurring before DBT.

Personality differences in patients with delayed sleep-wake phase disorder and non-24-h sleep-wake rhythm disorder relative to healthy sleepers.

Objective/background: Delayed sleep-wake phase disorder (DSWPD) is associated with a delayed timing of circadian rhythms, and this delay is suggested to be the basis of the disorder. However, this has been questioned due to frequent relapses following treatment based on this aetiology. Recent studies have emerged suggesting personality factors may contribute to sleep patterns in DSWPD.

Developing a successful treatment for co-morbid insomnia and sleep apnoea.

Insomnia and sleep apnoea are the two most common sleep disorders, found in 6% and 23-50% of the general population respectively. These disorders also frequently co-occur, with 39-58% of sleep apnoea patients reporting symptoms indicative of co-morbid insomnia. When these disorders co-occur, clinicians are faced with difficult treatment decisions, patients experience the additive detrimental impacts of both disorders, and the effectiveness of discrete treatments for each disorder may be impaired.

The etiology of delayed sleep phase disorder.

According to classification manuals for sleep disorders, nine disorders are directly related to biological clock timing misalignments. Of all, delayed sleep phase disorder (DSPD) is the most commonly diagnosed, predominantly affecting adolescents, young adults, and insomnia patients. It is a persistent inability to fall asleep at earlier, more desirable and socially conventional times, coupled with extreme difficulty awakening in the morning.

Beliefs about the 'shape' and continuity of healthy sleep as a function of age.

Objective: Treating insomnia includes challenging unrealistic beliefs that may contribute to anxieties and wakefulness. This study explored beliefs about the shape and continuity of healthy adult sleep at different adult ages.

Methods: Younger (n=113, M=21.

The relationship between a night's sleep and subsequent daytime functioning in older poor and good sleepers.

Those suffering insomnia symptoms generally report daytime impairments. However, research has not assessed whether this relationship holds on a nightly basis, despite the strongly held belief that a night of poor sleep impairs mood and functioning the following day. The objective of this study was to test this relationship in a group of older poor sleepers with insomnia symptoms compared with good sleepers.

The impact of sleep on adolescent depressed mood, alertness and academic performance.

The present study developed and tested a theoretical model examining the inter-relationships among sleep duration, sleep quality, and circadian chronotype and their effect on alertness, depression, and academic performance. Participants were 385 adolescents aged 13-18 years (M = 15.6, SD = 1.

Public health implications of sleep loss: the community burden.

Poor sleep imparts a significant personal and societal burden. Therefore, it is important to have accurate estimates of its causes, prevalence and costs to inform health policy. A recent evaluation of the sleep habits of Australians demonstrates that frequent (daily or near daily) sleep difficulties (initiating and maintaining sleep, and experiencing inadequate sleep), daytime fatigue, sleepiness and irritability are highly prevalent (20%-35%).

Estimating adolescent sleep patterns: parent reports versus adolescent self-report surveys, sleep diaries, and actigraphy.

Background: In research and clinical contexts, parent reports are often used to gain information about the sleep patterns of their adolescents; however, the degree of concordance between parent reports and adolescent-derived measures is unclear. The present study compares parent estimates of adolescent sleep patterns with adolescent self-reports from surveys and sleep diaries, together with actigraphy.

Methods: A total of 308 adolescents (59% male) aged 13-17 years completed a school sleep habits survey during class time at school, followed by a 7-day sleep diary and wrist actigraphy.

The sleep patterns and well-being of Australian adolescents.

Aim: Adolescent sleep patterns vary between countries, and these differences influence adolescent functioning and well-being. The present study provides data on the sleep and well-being of Australian adolescents.

Methods: 385 adolescents aged 13-18 years were recruited from 8 South Australian schools spanning the socio-economic spectrum.

A cross-cultural comparison of sleep duration between US And Australian adolescents: the effect of school start time, parent-set bedtimes, and extracurricular load.

Study Objective: To test whether sleep duration on school nights differs between adolescents in Australia and the United States and, if so, whether this difference is explained by cultural differences in school start time, parental involvement in setting bedtimes, and extracurricular commitments.

Participants: Three hundred eighty-five adolescents aged 13 to 18 years (M = 15.57, SD = 0.

The discrepancy between actigraphic and sleep diary measures of sleep in adolescents.

Objective: To explore the discrepancy between sleep diary and actigraphic measures of sleep in adolescents and to ascertain whether these discrepancies may vary according to characteristics of the participant.

Methods: Participants were 385 adolescents aged 13-18years (X=15.6, standard deviation [SD]=0.

Time for bed: parent-set bedtimes associated with improved sleep and daytime functioning in adolescents.

Study Objectives: To determine the proportion of adolescents whose bedtime is set by their parents and to evaluate whether parent-set bedtimes are associated with earlier bedtimes, more sleep, and better daytime functioning.

Participants: 385 adolescents aged 13-18 years (mean = 15.6, SD = 0.

The relationship between insomnia and body temperatures.

Sleepiness and sleep propensity are strongly influenced by our circadian clock as indicated by many circadian rhythms, most commonly by that of core body temperature. Sleep is most conducive in the temperature minimum phase, but is inhibited in a "wake maintenance zone" before the minimum phase, and is disrupted in a zone following that phase. Different types of insomnia symptoms have been associated with abnormalities of the body temperature rhythm.

Treating chronobiological components of chronic insomnia.

Circadian rhythms have a strong effect on the ability to sleep across the 24-h period. Maximum sleepiness occurs at the phase of lower endogenous core body temperature. This period is bracketed by two periods of alertness: a "wake-maintenance zone" occurring 6-10h before the time of core temperature minimum, and a "wake-up zone" occurring 4-7h after the minimum.