Materiały źródłowe

• #1 Delayed sleep phase syndrome: pathophysiology and treatment options – PubMed

  https://pubmed.ncbi.nlm.nih.gov/15532214/

  This paper presents a comprehensive review of delayed sleep phase syndrome (DSPS), a circadian-rhythm sleep disorder thought to result from the endogenous circadian pacemaker being „stuck” at a later-than-normal phase, relative to the desired sleep-wake schedule. […] However, caution is raised for the reason that more than 20 years after its initial description in the literature, the basic pathophysiology of DSPS remains poorly understood, as observed in the 2003 National Sleep Disorders Research Plan. […] Challenges for future research include elucidating the exact sleep homeostatic and circadian contributions to the disorder, improving the objective verification of this diagnosis instead of relying only on self-report information, and conducting treatment research aimed at determining efficacy, effectiveness, and mechanism or mechanisms of action.

• #1 Delayed sleep phase disorder – Wikipedia

  https://en.wikipedia.org/wiki/Delayed_sleep_phase_disorder

  Delayed sleep phase disorder (DSPD), more often known as delayed sleep phase syndrome and also as delayed sleep-wake phase disorder, is the delaying of a person’s circadian rhythm (biological clock) compared to those of societal norms. The disorder affects the timing of biological rhythms including sleep, peak period of alertness, core body temperature, and hormonal cycles. […] The orexin system was only identified in 1998, yet it appears intimately implicated in human sleep-wake systems. […] DSPD is a disorder of the body’s timing system—the biological clock. Individuals with DSPD might have an unusually long circadian cycle, might have a reduced response to the resetting effect of daylight on the body clock, and/or may respond overly to the delaying effects of evening light and too little to the advancing effect of light earlier in the day.

• #1 Delayed sleep-wake phase disorder – UpToDate

  https://www.uptodate.com/contents/delayed-sleep-wake-phase-disorder

  Delayed sleep-wake phase disorder (DSWPD) is the most commonly encountered circadian rhythm sleep-wake phase disorder in adolescents. Like other circadian rhythm disorders, DSWPD results from failure to synchronize internal circadian rhythms to the environmental light/dark cycle. […] Individuals with DSWPD have a pronounced „night owl” circadian preference. Affected individuals habitually go to bed and wake up significantly later than conventional or desired times. Unlike unaffected „night owls,” patients with DSWPD cannot conform to a sleep schedule that is compatible with personal, professional, or academic obligations. […] The prevalence of delayed sleep-wake phase disorder (DSWPD) is highest in adolescents and young adults, with rates estimated between 3.3 and 4.6 percent. Comparisons of individual studies are complicated by the use of inconsistent diagnostic criteria and the use of evening chronotype as a proxy for actual DSWPD. Differences in school start times (later in Western Europe compared with many high schools in the United States) may explain some of the regional variability. […] The prevalence of DSWPD in adults is lower, with estimates between 0.2 to 1.7 percent. Although the prevalence of familial DSWPD has not been established, a family history is often present among afflicted individuals. Males and females seem to be affected in equal proportions.

• #1 Sleeplessness and Circadian Rhythm Disorder: Background, Etiology, Pathophysiology

  https://emedicine.medscape.com/article/1188944-overview

  The neural basis of the circadian rhythm, the suprachiasmatic nuclei (SCN), is located in the anterior ventral hypothalamus and has been identified as the substrate that generates circadian activity. SCN lesions produce loss of circadian rhythmicity of the sleep-wake cycle, the activity-rest cycle, skin temperature, and corticosteroid secretion. […] Other pacemakers that are not located in the SCN are observed. For instance, core body temperature rhythm persists despite bilateral ablation of SCN. Furthermore, free-running studies have provided evidence for multiple circadian oscillators. Under free-running conditions, circadian rhythm may split into independent components.

• #1 Delayed sleep-wake phase disorder – Nesbitt – Journal of Thoracic Disease

  https://jtd.amegroups.org/article/view/18434/html

  Numerous factors are likely to contribute to the pathophysiology of DSWPS, including behavioural and psychological, as well as biological factors. In terms of the latter, individual differences in neural responses to light, genetics and sleep homeostasis are likely to be of importance. […] At the core of the pathophysiology of DSWPD is the likely scenario that patients receive too much light exposure in the phase delaying portion of their phase response curve to light, and too little, or none, in the phase advancing portion, by virtue of the fact they are asleep. This then generates self-perpetuating mal entrainment: the period length of the sleep-wake cycle approximates that of the solar cycle (24 h), but its phase is inappropriately delayed relative to it. […] It has also been postulated that the intrinsic circadian period (or tau) of patients with DSWPD, which are determined by the temporal course of the molecular feedback loops within neurons of the suprachiasmatic nucleus, may be modestly longer than that of normal chronotypes (which is on average 24.17 h).

• #1 Scientists discover how a common mutation leads to 'night owl’ sleep disorder | ScienceDaily

  https://www.sciencedaily.com/releases/2020/10/201027105354.htm

  People with delayed sleep phase disorder are unable to fall asleep until late at night (often after 2 a.m.) and have difficulty getting up in the morning. […] In 2017, scientists discovered a surprisingly common mutation that causes this sleep disorder by altering a key component of the biological clock that maintains the body’s daily rhythms. […] The new findings, published October 26 in Proceedings of the National Academy of Sciences, reveal the molecular mechanisms involved and point the way toward potential treatments. […] A shortened clock cycle causes people to go to sleep and wake up earlier than normal (the „morning lark” effect), while a longer clock cycle makes people stay up late and sleep in (the „night owl” effect). […] The genetic variant identified in the 2017 study, however, was found in around one in 75 people of European descent.

• #1

  https://www.advocatehealth.com/health-services/sleep-medicine/delayed-sleep-phase-syndrome

  Delayed sleep phase syndrome disrupts your natural sleep-wake cycle. If you have delayed sleep phase syndrome, your bodys internal clock is delayed by several hours, causing you to fall asleep and wake up later than usual. […] Research indicates that individuals with delayed sleep phase syndrome may have a longer circadian rhythm cycle, making it hard for them to adapt to a 24-hour day. This extended cycle, coupled with modern lifestyle factors such as late-night screen use, can perpetuate the delay in sleeping and waking times. […] However, if you have a circadian rhythm sleep disorder like delayed sleep phase syndrome, this natural cycle is delayed. This delay affects your ability to fall asleep and wake up when you need to, making it challenging to function according to typical schedules.

• #1 Delayed sleep phase disorder, circadian genes, sleep homeostasis and light sensitivity (Chapter 31) – The Genetic Basis of Sleep and Sleep Disorders

  https://www.cambridge.org/core/books/genetic-basis-of-sleep-and-sleep-disorders/delayed-sleep-phase-disorder-circadian-genes-sleep-homeostasis-and-light-sensitivity/6014CBE230AC9435F0AD339B92EC8482

  People suffering with delayed sleep phase disorder (DSPD) generally have normal sleep duration and quality when given ample sleep opportunity, but have sleep onset insomnia and sleep schedules that are severely delayed compared to the general population. […] Even though it has been shown that alterations in sleep homeostasis may contribute to variation in sleep timing preference, there is now good evidence showing that evening preference is correlated with longer circadian period. […] An important contributory factor in DSPD is light: excess artificial light at night will delay the circadian clock and reduced exposure to morning light will not help to advance the clock. […] Importantly, there are significant individual differences in the sensitivity to the effects of melatonin suppression by light, and this raises the important question as to whether the risk of DSPD could also be associated with individual differences in sensitivity to light.

• #1 How to Identify and Treat Delayed Sleep Phase Syndrome – eachnight

  https://eachnight.com/sleep/delayed-sleep-phase-syndrome/

  Delayed Sleep Phase Syndrome: This syndrome involves a significant delay in a persons natural sleep-wake cycle. People with this condition typically struggle to fall asleep at a conventional bedtime and may experience their most restful sleep during unconventional hours, such as the late morning. […] Research suggests that this may occur due to abnormalities in the circadian system (that is in our body clock physiology). […] One possible explanation is that Delayed Sleep Phase Syndrome could be a reduced response to light in the morning. This means your body isnt properly reacting when it gets hit with warm sunlight in the early morning. A general lack of morning sunlight exposure could also result in having a hard time waking up. Scientists also believe it could be a reduced response to the lack of light in the evening. If your response is reduced or delayed, it would take much longer to fall asleep. One final possibility is that it is an overstimulated response to longer exposure to light. Living in a place with lots of sunlight or a place with long summer hours can make this disorder even more difficult to live with. […] Overall, there is no clear, specific cause that scientists can point to. Scientists have begun to identify the important genes that it is associated with, which means that Delayed Sleep Phase Syndrome could be hereditary.

• #1 Delayed Sleep Phase Syndrome (DSPS): Symptoms & Treatment

  https://my.clevelandclinic.org/health/diseases/14295-delayed-sleep-phase-syndrome-dsps

  Delayed sleep phase syndrome has a genetic cause. […] Research suggests that the genetic component makes your body’s natural circadian rhythm longer than average. This can affect your body’s desire to fall asleep at a scheduled time. […] Delayed sleep phase syndrome is a type of sleep disorder called a circadian rhythm sleep disorder. Your circadian rhythm is a 24-hour cycle that helps you stay awake during the day and fall asleep at night. This cycle regulates how certain parts of your body function, like your body temperature and digestion. […] Delayed sleep phase syndrome may cause the following complications: Depression: Your ability to sleep can affect your mood and stamina. Over 60% of people diagnosed with delayed sleep phase syndrome experience depression. […] Some healthcare providers recommend light therapy as a treatment for delayed sleep phase syndrome.

• #1 Scientists discover how a common mutation leads to ‘night owl’ sleep disorder | University of California

  https://www.universityofcalifornia.edu/news/scientists-discover-how-common-mutation-leads-night-owl-sleep-disorder

  A new study by researchers at UC Santa Cruz shows how a genetic mutation throws off the timing of the biological clock, causing a common sleep syndrome called delayed sleep phase disorder. […] In 2017, scientists discovered a surprisingly common mutation that causes this sleep disorder by altering a key component of the biological clock that maintains the body’s daily rhythms. […] The genetic variant identified in the 2017 study, however, was found in around one in 75 people of European descent. […] This genetic marker is really widespread, Partch said. We still have a lot to understand about the role of lengthened clock timing in delayed sleep onset, but this one mutation is clearly an important cause of late night behavior in humans. […] Partch has been studying the molecular structures and interactions of the clock proteins for years. In a study published earlier this year, her lab showed how certain mutations can shorten clock timing by affecting a molecular switch mechanism, making some people extreme morning larks.

• #1 Scientists discover how a common mutation leads to 'night owl’ sleep disorder | ScienceDaily

  https://www.sciencedaily.com/releases/2020/10/201027105354.htm

  „This genetic marker is really widespread,” Partch said. „We still have a lot to understand about the role of lengthened clock timing in delayed sleep onset, but this one mutation is clearly an important cause of late night behavior in humans.” […] The mutation affects a protein called cryptochrome, one of four main clock proteins. […] The cryptochrome mutation causes a small segment on the „tail” of the protein to get left out, and Partch’s lab found that this changes how tightly cryptochrome binds to the CLOCK:BMAL1 complex. […] „The region that gets snipped out actually controls the activity of cryptochrome in a way that leads to a 24-hour clock,” Partch explained. „Without it, cryptochrome binds more tightly and stretches out the length of the clock each day.” […] „How tightly the complex partners bind to this pocket determines how quickly the clock runs,” Partch explained. […] „We know now that we need to target that pocket to develop therapeutics that could shorten the clock for people with delayed sleep phase disorder,” she said.

• #1 Delayed sleep-wake phase disorder – Nesbitt – Journal of Thoracic Disease

  https://jtd.amegroups.org/article/view/18434/html

  However, a recent study of unrelated families showing strong heritability of DSWPD elucidated a gain of function mutation in the CRY1 clock gene, which creates a transcriptional inhibitor with enhanced affinity for circadian activator proteins Clock and Bmal1. This allele is found in 0.6% of the population, and may play a significant role in delayed sleep timing. […] A further mechanism contributing to the development of DSWPD is likely to be intrinsic differences in sleep homeostasis in individuals who develop the disorder. Slow wave sleep precipitously falls in mid puberty, a critical window during which DSWPD symptoms can emerge, which could give credence to the theory that alterations in sleep homeostasis could precipitate development of the disorder.

• #1 Delayed sleep-wake phase disorder

  https://researchfeatures.com/delayed-sleep-wake-phase-disorder/

  Delayed sleep-wake phase disorder (DSWPD) is a circadian rhythm disorder, characterised by a late onset of sleep and wakefulness compared to conventional times or a night owl preference. […] The exact cause of DSWPD has remained elusive. Researchers have hypothesised that both genetic and environmental factors play a role in initiating and exacerbating this condition. […] Polymorphism in the circadian clock gene hPer3, human leukocyte antigen, and Clock are found to be associated with DSWPD onset and progression. […] A 2017 study published in Cell identified a gene involved in the circadian clock, CRY1, to play a role in DSWPD. […] A gain-of-function mutation leads to increased CRY1 protein expression and inhibition of target genes: Clock and BMAL1. […] Altogether, it is associated with increased period of molecular circadian rhythms in cells and delayed sleep onset.

• #1 Delayed sleep-wake phase disorder | MedLink Neurology

  https://www.medlink.com/articles/delayed-sleep-wake-phase-disorder

  Delayed sleep-wake phase disorder is due to a misalignment between the body’s endogenous circadian rhythm and the social environment. […] The mechanism underlying delayed sleep-wake phase disorder involves a delay in the timing of the circadian pacemaker. Proposed causes for this delay include decreased response to the phase-advancing effect of morning light, an increased responsiveness to the delaying effects of evening light, and a longer than average circadian cycle. […] Delayed sleep-wake phase disorder is theorized to develop due to multiple possible factors, including decreased response to the phase-advancing effect of morning light, an increased responsiveness to the delaying effects of evening light, and a longer than average circadian cycle. However, work shows that the magnitude of circadian shift with light exposure may be similar in adults regardless of age. […] There are familial cases, indicating a genetic basis for delayed sleep-wake phase disorder. Susceptibility to delayed sleep-wake phase disorder may involve polymorphisms of the circadian gene Per3 and its promoter region.

• #1 What Is Delayed Sleep Phase Syndrome?

  https://www.verywellhealth.com/delayed-sleep-phase-syndrome-overview-4585048

  Delayed sleep phase syndrome (DSPS) occurs in people whose circadian rhythms (cyclical sleep patterns) are set two hours or more later than in most people. […] Delayed sleep phase syndrome also is closely linked with attention deficit hyperactivity disorder (ADHD), with some studies suggesting a higher risk of heart problems in these people. […] There seems to be a genetic predisposition towards developing delayed sleep phase syndrome. Some of this science is understood. For example, a mutation in the CRY1 gene alters the human circadian clock, delaying sleep by two to two-and-a-half hours compared to non-carriers. […] As researchers discover more about DSPS, they will identify more of these so-called „clock genes” that play a role in the syndrome. […] Current research shows a hereditary component in 40% to 50% of „clock types” whether you are a morning person or a night owl.

• #1

  https://www.omim.org/entry/614163

  A number sign (#) is used with this entry because of evidence that susceptibility to delayed sleep phase disorder (DSPD) is conferred by heterozygous mutation in the CRY1 gene (601933) on chromosome 12q23. […] Delayed sleep phase syndrome (DSPD) is a circadian rhythm sleep disorder characterized by sleep-onset insomnia and difficulty in awakening at the desired time. Patients with DSPD have chronic difficulty in adjusting their sleep-onset and wake-up times to occupational, school, and social activities. Although psychosocial and environmental factors sometimes induce this kind of disorder, most patients with DSPD appear to have an abnormal circadian pacemaker and/or an abnormal entrainment system (summary by Hohjoh et al., 2003). […] In affected members of 7 unrelated families, mostly of Turkish origin, with DSPD, Patke et al. (2017) identified a splice site mutation in the CRY1 gene (601933.0001). Analysis of cells from 1 patient confirmed that the mutation resulted in deletion of exon 11 with an in-frame deletion of 24 residues in the C-terminal region. The mutation in the first family was found by a combination of candidate gene and whole-exome sequencing. The mutation segregated with the disorder in all families; there were 31 heterozygous carriers and 8 homozygous carriers, and there were no phenotypic differences between heterozygous and homozygous carriers. The variant was found at a frequency of 0.6% in databases of human genetic variation: minor allele frequency of 0.0012 in the 1000 Genomes Project and 0.004335 in the ExAC databases; this frequency lies within the reported range of DSPD prevalence in the general population. In vitro functional expression studies in mouse embryonic fibroblasts showed that mutant CRY1 increased the circadian period by approximately half an hour compared to wildtype, which was similar to the human phenotype. The mutant protein showed increased localization to the nucleus compared to wildtype, and it had increased interaction with its target transcription factors CLOCK (601851) and ARNTL (602550), resulting in increased transcriptional inhibition consistent with a gain of function. Chromatin immunoprecipitation studies indicated that the CRY1 mutation displaced the CLOCK and ARNTL transcription factor from chromatin at their target gene promoters, resulting in decreased expression of these target genes.

• #1 Insomnia | Atrium Health Wake Forest Baptist

  https://www.wakehealth.edu/condition/i/insomnia

  Delayed sleep phase syndrome (DSPS) is believed to be a disorder of the body’s timing system the biological clock. […] DSPS is found in persons who get a normal or nearly normal amount of sleep, but the entire sleep cycle is shifted later than normal.

• #1 What Is Delayed Sleep Phase Syndrome?

  https://www.verywellhealth.com/delayed-sleep-phase-syndrome-overview-4585048

  Beyond genetic programming, there are environmental factors that may unmask the condition. Most importantly, light has powerful effects on the timing of the circadian system. It may provoke the delay in sleep timing. However, it may also be used to correct the condition. […] Sleep is dependent on two processes: sleep drive and the circadian alerting system. […] It is controlled by the suprachiasmatic nucleus, a region of cells in the hypothalamus of the brain, and is highly influenced by light exposure. […] Exposure to natural light in the early morning hours is a signal to the brain for wakefulness. […] It also slightly shifts the timing of sleep earlier, making it easier to fall asleep. […] Without it, significant problems can develop with sleep and health. […] Delayed sleep phase syndrome can be treated.

• #1 Delayed sleep-wake phase disorder

  https://researchfeatures.com/delayed-sleep-wake-phase-disorder/

  Decreased exposure to bright light in the morning and increased exposure to light late in the evening can exacerbate the delayed circadian phase, which causes individuals to have the desire to fall asleep and arise later than usual times. […] The sleep-wake cycle is driven by determinants of the internal circadian rhythm. […] In DSWPD, process C is misaligned with the desired sleep/wake cycle and continues to strongly oppose sleep onset at the desired time even in the presence of accumulated sleep deprivation. […] A combination light therapy has also been suggested as a potential treatment option for DSWPD patients. […] Therefore, the success of therapy requires personal motivation to maintain a rigid schedule. […] Both therapies require patients to fix their daily schedule, which would cause initial anxiety. Thus, successful treatment depends on personal motivation to endure sleep deprivation initially and maintain a rigid schedule continuously.

• #1 Delayed sleep phase disorder – Wikipedia

  https://en.wikipedia.org/wiki/Delayed_sleep_phase_disorder

  The altered phase relationship between the timing of sleep and the circadian rhythm of body core temperature has been reported previously in DSPD patients studied in entrained conditions. […] Rather, the disorder may also reflect a fundamental inability of the endogenous circadian timing system to maintain normal internal phase relationships among physiological systems, and to properly adjust those internal relationships within the confines of the 24-hour day. […] DSPD patients may have a reduced capacity to achieve such a change in phase angle in response to entrainment. […] It has also been hypothesized that, due to the altered phase angle between sleep and temperature observed in DSPD, and the tendency for longer sleep periods, these individuals may simply sleep through the phase-advance portion of the light PRC.

• #1 Delayed sleep phase disorder | Healthify

  https://healthify.nz/health-a-z/d/delayed-sleep-phase-disorder

  Delayed sleep phase disorder (DSPD) is thought to happen when your internal clock (circadian rhythm) is out of sync with the environment. […] Your body’s circadian rhythm is controlled mainly by the hormone melatonin. […] With teenagers, DSPD may be partly due to biological reasons as the onset of the melatonin hormone production begins on average about an hour later in teens than adults.

• #1 Delayed Sleep Phase Syndrome (DSPS) | Sleep Health Foundation

  https://www.sleephealthfoundation.org.au/sleep-disorders/delayed-sleep-wake-phase-disorder-dswpd

  Your body contains an internal clock that regulates when you wake up and when you go to sleep. If you have DSPS, this clock is not properly synchronised to the environment. The hormone melatonin is not being produced at the right time. This causes a mismatch between when you think you should go to bed and when you are able to go to sleep. […] Melatonin production begins and ends much later, making the timing of your sleep much later. Melatonin production is highly sensitive to light, particularly blue light emitted by devices such as phones, tablets and computers. […] If you have DSPS, you have a higher chance of getting depression and insomnia.

• #1 What Is Delayed Sleep Phase Syndrome?

  https://www.verywellhealth.com/delayed-sleep-phase-syndrome-overview-4585048

  There are effective ways to keep the timing of sleep in a normal phase. […] It may require a little extra effort, but consider the following potentially helpful interventions. […] There is good evidence that night owls can maintain a socially acceptable sleep timing. […] It is especially important to reset the timing of sleep with morning sunlight. […] Light therapies also are used in clinical settings to treat DSPS. […] Artificial screen light should be minimized at night, especially in the hours preceding bedtime. […] Melatonin is a hormone produced overnight by the pineal gland in the brain. […] It can be an external signal to the circadian system, most effective among the blind. […] If taken up to six hours before the desired bedtime, it may help night owls to fall asleep earlier.

• #1 UCSF Delayed Sleep Phase Trial → Lemborexant in Delayed Sleep Phase Syndrome

  https://clinicaltrials.ucsf.edu/trial/NCT05463861

  Delayed sleep phase syndrome (DSPS) is a disorder in which a person’s sleep is delayed by two hours or more beyond what is considered an acceptable or conventional bedtime. The delayed sleep then causes difficulty in being able to wake up at the desired time. […] Two phenotypes of DSPS are recognized depending on the phase of entrainment: one with a late phase and normal phase angle (non-circadian) and other with a late phase and abnormal phase angle (circadian). The differentiation of these two phenotypes is theoretical: a mixed situation may be involved in some cases and the exact pathophysiology of each subtype is still controversial. […] In theory, however, separating the sample into these two subtypes is likely important to predict short- and long-term responses to orexin antagonists in DSPS.

• #1

  https://www.aurorahealthcare.org/services/sleep-disorders/delayed-sleep-phase-syndrome

  Delayed sleep phase syndrome affects your body’s natural sleep-wake cycle. If you have delayed sleep phase syndrome, your natural sleep pattern is delayed by two or more hours compared to conventional sleep times. […] The exact cause of delayed sleep phase disorder is not entirely understood, but several factors may contribute to its development. Genetics can play a significant role, as delayed sleep phase syndrome often runs in families. Environmental factors, such as exposure to light at night, can also impact your circadian rhythm. Lifestyle habits such as irregular sleep patterns and inconsistent bedtimes can make the condition worse. In some cases, underlying medical or psychiatric conditions may be linked to delayed sleep phase syndrome. […] Theres a notable association between delayed sleep phase syndrome and attention deficit hyperactivity disorder (ADHD). Many individuals with ADHD experience sleep disorders, including delayed sleep phase syndrome. The link is believed to be due to the overlap in the regulatory systems that manage attention, behavior and sleep. Proper diagnosis and treatment are crucial for managing both conditions effectively.

• #1

  https://www.advocatehealth.com/health-services/sleep-medicine/delayed-sleep-phase-syndrome

  There are many causes of delayed sleep phase disorder, which are not entirely understood. Delayed sleep phase syndrome often runs in families. Environmental factors, such as late-night exposure to light, can also disrupt your circadian rhythm. […] Individuals with ADHD often exhibit symptoms of delayed sleep phase syndrome, such as difficulty falling asleep at conventional bedtimes and excessive daytime sleepiness. […] Treatment for delayed sleep phase syndrome aims to shift your sleep-wake cycle to more conventional times. A sleep specialist will help you come up with effective strategies to improve your sleep pattern.

• #1 Delayed Sleep Phase Syndrome: Signs, ADHD Link, TreatmentsFooterLogo

  https://www.additudemag.com/delayed-sleep-phase-syndrome-signs-treatments-adhd/?srsltid=AfmBOooQ_UFuadKyxhoSm5Mq-11WkwqAuEIWJ5idzDBYOcv01apOi18b

  Delayed sleep phase syndrome is a sleep disorder that disrupts one’s ability to sleep and wake at conventional times. DSPS is commonly seen with ADHD. […] DSPS is frequently misdiagnosed or overlooked in individuals with ADHD, leading to ineffective treatments and continued sleep disturbances. […] Proper treatment of DSPS comprises specialized approaches like light therapy and melatonin supplementation, which aim to regulate the internal body clock and improve sleep quality. […] Accurate identification of DSPS – a treatable condition – is essential, as conventional approaches to manage sleep problems are often inadequate or ineffective for this sleep disorder. […] Managing DSPS requires knowledge of circadian physiology, as effective interventions for this sleep disorder target the internal clock.

• #1 Delayed Sleep Phase Syndrome: Symptoms, Causes, and Treatment

  https://www.verywellmind.com/delayed-sleep-phase-syndrome-symptoms-causes-and-treatment-7110083

  Delayed sleep phase syndrome (DSPS) is a circadian rhythm sleep disorder that can cause your sleep-time and wake-time to be much later than most peoples. […] This condition occurs due to a delay in the timing of your internal body clock, or circadian rhythm, compared to traditional sleep and wake timings. […] Delayed sleep phase syndrome typically emerges during puberty and affects teenagers, although it can sometimes persist into adulthood as well. […] A 2018 review notes that there is a significant link between delayed sleep phase syndrome and mental health conditionsup to 70% of people with delayed sleep phase syndrome have a psychiatric disorder, such as depression or bipolar disorder. […] These are some of the potential causes of delayed sleep phase syndrome: Hormonal imbalance: Hormones such as melatonin and cortisol help maintain your sleep-wake cycle by promoting sleepiness and wakefulness respectively. An imbalance in these hormones can lead to delayed sleep phase syndrome.

• #1 Delayed sleep phase syndrome is related to seasonal affective disorder

  https://escholarship.org/uc/item/4fj4q7jg

  Delayed sleep phase syndrome (DSPS) and seasonal affective disorder (SAD) may manifest similar delayed circadian phase problems. […] These cases suggested that DSPS is partially comorbid with SAD. These data support the hypothesis that DSPS and SAD may share a pathophysiological mechanism causing delayed circadian phase.

• #1 Everything You Should Know About Delayed Sleep Phase Syndrome – CNET

  https://www.cnet.com/health/sleep/delayed-sleep-phase-syndrome/

  Ultimately, she and her team are on the hunt to understand and answer one question: Can you change your clock, with light therapy so that you can move to an earlier time? […] Delayed sleep phase syndrome can be frustrating for people trying to work a 9-to-5 schedule. […] „It’s not as rare a disorder as people think. There’s still about 1 in 600 people that have the disorder and that’s half a million Americans; that’s three times as many people that have narcolepsy, even though a lot more people have heard of narcolepsy,” said Mansbach.

• #1 Delayed Sleep Phase | Sleep Disorders in Children

  https://www.childrensrespiratorydoctor.co.uk/delayed-sleep-phase.php

  Delayed Sleep Phase Syndrome is caused by changes in the body clock, which means that your child can’t fall asleep until very late and so has to sleep later than normal. […] The problem could be caused by your environment, which could be exposing you to too much bright light at night and convincing your body clock that it’s still daytime. It could also be caused by other problems, such as a lack of melatonin, which is essential for keeping the body clock running properly. In some cases there is genetic cause and many family members have delayed sleep phase. […] One technique that can work well is to gradually shift your child’s bedtime until it is at the right time. The best way to do this is actually to put your child to bed later each night until a normal sleep time is achieved. This technique, known as chornotherapy, is difficult to implement an can be impossible during term time as it will mean sleeping during the day for a little while. Shifting the bedtime backwards might seem quicker, but it doesn’t often help with a sleep delay as your child will just lie there, unable to sleep. […] In some cases, your doctor may prescribe a small dose of melatonin to be taken about an hour before going to bed. Taking this medication can help your child to feel sleepier at bedtime and it should help to shift their internal clock back to a more.

• #1 Delayed Sleep Phase Syndrome (DSPS): Symptoms & Treatment

  https://my.clevelandclinic.org/health/diseases/14295-delayed-sleep-phase-syndrome-dsps

  Your healthcare provider may recommend taking an over-the-counter melatonin supplement to help shift your circadian rhythm. […] Delayed sleep phase syndrome doesn’t go away. Treatment is ongoing to manage it. […] There’s no cure for delayed sleep phase syndrome (DSPS). Treatment is effective at improving your sleep to reduce your symptoms.

• #1 Night Owls Unite (My Life with Delayed Sleep Phase Disorder, Part II) | SRBR: Society for Research on Biological Rhythms

  https://srbr.org/night-owls-unite/

  In addition to genetic testing, biomarkers such as cortisol and melatonin levels can help “validate” that DSWPD is a physiological – not psychological – disorder. […] A portion of the population (the exact percentage is still unclear) with DSWPD is not capable of changing their sleep onset time. Regardless of willpower, exposure to light, adjusting room temperature or the timing of meals, their chronotype is intractable: it’s not a lifestyle choice or preference.

• #1 Sleep Phase Disorders and Biological Clock Proteins: Molecular Switch Mechanism Explains How Mutations Shorten Clocks | Sleep Review

  https://sleepreviewmag.com/sleep-disorders/circadian-rhythm-disorders/delayed-phase/sleep-phase-disorders-and-biological-clock-proteins-molecular-switch-mechanism-explains-how-mutations-shorten-clocks/

  A new study of molecular interactions central to the functioning of biological clocks explains how certain mutations can shorten clock timing, making some people extreme morning larks because their internal clocks operate on a 20-hour cycle instead of being synchronized with the 24-hour cycle of day and night. […] Many people with sleep phase disorders have changes in their clock proteins, says Carrie Partch, PhD, associate professor of chemistry and biochemistry at UC Santa Cruz and a corresponding author of the paper, in a release. […] In the new study, researchers focused on mutations in an enzyme called casein kinase 1 (CK1), which regulates a core clock protein called PERIOD (or PER). […] Clock-altering mutations in CK1 had been known for years, but it was unclear how they changed the timing of the clock.

• #1 Sleep Phase Disorders and Biological Clock Proteins: Molecular Switch Mechanism Explains How Mutations Shorten Clocks | Sleep Review

  https://sleepreviewmag.com/sleep-disorders/circadian-rhythm-disorders/delayed-phase/sleep-phase-disorders-and-biological-clock-proteins-molecular-switch-mechanism-explains-how-mutations-shorten-clocks/

  PER proteins are part of a complex feedback loop in which changes in their abundance set the timing of circadian rhythms, so mutations that increase the rate of PER degradation throw off the clock. […] What we discovered is this neat molecular switch that controls the abundance of the PER proteins. […] The switch involves a section of the CK1 protein called the activation loop. […] The clock-changing mutations in CK1 cause it to favor this degron-binding conformation. […] The stabilization of PER can be disrupted by either the FASP mutations, which interfere with the binding of CK1 to this region, or by the mutations in CK1 that favor the alternate conformation of the activation loop. […] This stabilizing region builds a delay into the clock to make it align with Earths 24-hour day.

• #1 Sleep Phase Disorders and Biological Clock Proteins: Molecular Switch Mechanism Explains How Mutations Shorten Clocks | Sleep Review

  https://sleepreviewmag.com/sleep-disorders/circadian-rhythm-disorders/delayed-phase/sleep-phase-disorders-and-biological-clock-proteins-molecular-switch-mechanism-explains-how-mutations-shorten-clocks/

  Understanding these molecular mechanisms may enable scientists to develop therapies for intervening in the clock to alleviate disruptions, whether they are caused by inherited conditions or by shift work or jet lag. […] Our results provide a mechanistic foundation to understand the essentially universal role of CK1 as a regulator of eukaryotic circadian clocks.

• #1 Scientists discover how a common mutation leads to ‘night owl’ sleep disorder – News

  https://news.ucsc.edu/2020/10/night-owls.html

  A new study by researchers at UC Santa Cruz shows how a genetic mutation throws off the timing of the biological clock, causing a common sleep syndrome called delayed sleep phase disorder. […] The genetic variant identified in the 2017 study, however, was found in around one in 75 people of European descent. […] This genetic marker is really widespread, Partch said. We still have a lot to understand about the role of lengthened clock timing in delayed sleep onset, but this one mutation is clearly an important cause of late night behavior in humans. […] Partchs lab is currently doing just that, conducting screening assays to identify molecules that bind to the pocket in the clocks molecular complex. We know now that we need to target that pocket to develop therapeutics that could shorten the clock for people with delayed sleep phase disorder, she said.

• #2 Delayed sleep phase disorder – Wikipedia

  https://en.wikipedia.org/wiki/Delayed_sleep_phase_disorder

  Delayed sleep phase disorder (DSPD), more often known as delayed sleep phase syndrome and also as delayed sleep-wake phase disorder, is the delaying of a person’s circadian rhythm (biological clock) compared to those of societal norms. The disorder affects the timing of biological rhythms including sleep, peak period of alertness, core body temperature, and hormonal cycles. […] The orexin system was only identified in 1998, yet it appears intimately implicated in human sleep-wake systems. […] DSPD is a disorder of the body’s timing system—the biological clock. Individuals with DSPD might have an unusually long circadian cycle, might have a reduced response to the resetting effect of daylight on the body clock, and/or may respond overly to the delaying effects of evening light and too little to the advancing effect of light earlier in the day.

• #2 Delayed sleep-wake phase disorder – UpToDate

  https://www.uptodate.com/contents/delayed-sleep-wake-phase-disorder

  Delayed sleep-wake phase disorder (DSWPD) is the most commonly encountered circadian rhythm sleep-wake phase disorder in adolescents. Like other circadian rhythm disorders, DSWPD results from failure to synchronize internal circadian rhythms to the environmental light/dark cycle. […] Individuals with DSWPD have a pronounced „night owl” circadian preference. Affected individuals habitually go to bed and wake up significantly later than conventional or desired times. Unlike unaffected „night owls,” patients with DSWPD cannot conform to a sleep schedule that is compatible with personal, professional, or academic obligations. […] The prevalence of delayed sleep-wake phase disorder (DSWPD) is highest in adolescents and young adults, with rates estimated between 3.3 and 4.6 percent. Comparisons of individual studies are complicated by the use of inconsistent diagnostic criteria and the use of evening chronotype as a proxy for actual DSWPD. Differences in school start times (later in Western Europe compared with many high schools in the United States) may explain some of the regional variability. […] The prevalence of DSWPD in adults is lower, with estimates between 0.2 to 1.7 percent. Although the prevalence of familial DSWPD has not been established, a family history is often present among afflicted individuals. Males and females seem to be affected in equal proportions.

• #2 Delayed sleep phase disorder – Wikipedia

  https://en.wikipedia.org/wiki/Delayed_sleep_phase_disorder

  The altered phase relationship between the timing of sleep and the circadian rhythm of body core temperature has been reported previously in DSPD patients studied in entrained conditions. […] Rather, the disorder may also reflect a fundamental inability of the endogenous circadian timing system to maintain normal internal phase relationships among physiological systems, and to properly adjust those internal relationships within the confines of the 24-hour day. […] DSPD patients may have a reduced capacity to achieve such a change in phase angle in response to entrainment. […] It has also been hypothesized that, due to the altered phase angle between sleep and temperature observed in DSPD, and the tendency for longer sleep periods, these individuals may simply sleep through the phase-advance portion of the light PRC.

• #2 Delayed sleep phase disorder, circadian genes, sleep homeostasis and light sensitivity (Chapter 31) – The Genetic Basis of Sleep and Sleep Disorders

  https://www.cambridge.org/core/books/genetic-basis-of-sleep-and-sleep-disorders/delayed-sleep-phase-disorder-circadian-genes-sleep-homeostasis-and-light-sensitivity/6014CBE230AC9435F0AD339B92EC8482

  People suffering with delayed sleep phase disorder (DSPD) generally have normal sleep duration and quality when given ample sleep opportunity, but have sleep onset insomnia and sleep schedules that are severely delayed compared to the general population. […] Even though it has been shown that alterations in sleep homeostasis may contribute to variation in sleep timing preference, there is now good evidence showing that evening preference is correlated with longer circadian period. […] An important contributory factor in DSPD is light: excess artificial light at night will delay the circadian clock and reduced exposure to morning light will not help to advance the clock. […] Importantly, there are significant individual differences in the sensitivity to the effects of melatonin suppression by light, and this raises the important question as to whether the risk of DSPD could also be associated with individual differences in sensitivity to light.

• #2 Delayed sleep-wake phase disorder

  https://researchfeatures.com/delayed-sleep-wake-phase-disorder/

  Decreased exposure to bright light in the morning and increased exposure to light late in the evening can exacerbate the delayed circadian phase, which causes individuals to have the desire to fall asleep and arise later than usual times. […] The sleep-wake cycle is driven by determinants of the internal circadian rhythm. […] In DSWPD, process C is misaligned with the desired sleep/wake cycle and continues to strongly oppose sleep onset at the desired time even in the presence of accumulated sleep deprivation. […] A combination light therapy has also been suggested as a potential treatment option for DSWPD patients. […] Therefore, the success of therapy requires personal motivation to maintain a rigid schedule. […] Both therapies require patients to fix their daily schedule, which would cause initial anxiety. Thus, successful treatment depends on personal motivation to endure sleep deprivation initially and maintain a rigid schedule continuously.

• #2 Scientists discover how a common mutation leads to ‘night owl’ sleep disorder | University of California

  https://www.universityofcalifornia.edu/news/scientists-discover-how-common-mutation-leads-night-owl-sleep-disorder

  A new study by researchers at UC Santa Cruz shows how a genetic mutation throws off the timing of the biological clock, causing a common sleep syndrome called delayed sleep phase disorder. […] In 2017, scientists discovered a surprisingly common mutation that causes this sleep disorder by altering a key component of the biological clock that maintains the body’s daily rhythms. […] The genetic variant identified in the 2017 study, however, was found in around one in 75 people of European descent. […] This genetic marker is really widespread, Partch said. We still have a lot to understand about the role of lengthened clock timing in delayed sleep onset, but this one mutation is clearly an important cause of late night behavior in humans. […] Partch has been studying the molecular structures and interactions of the clock proteins for years. In a study published earlier this year, her lab showed how certain mutations can shorten clock timing by affecting a molecular switch mechanism, making some people extreme morning larks.

• #2 How a Genetic Mutation Causes Delayed Sleep Phase Disorder | Sleep Review

  https://sleepreviewmag.com/sleep-disorders/circadian-rhythm-disorders/delayed-phase/genetic-mutation-causes-delayed-phase-disorder/

  This genetic marker is really widespread. […] We still have a lot to understand about the role of lengthened clock timing in delayed sleep onset, but this one mutation is clearly an important cause of late night behavior in humans. […] The mutation affects a protein called cryptochrome, one of four main clock proteins. […] The cryptochrome mutation causes a small segment on the tail of the protein to get left out, and Partch’s lab found that this changes how tightly cryptochrome binds to the CLOCK:BMAL1 complex. […] The region that gets snipped out actually controls the activity of cryptochrome in a way that leads to a 24-hour clock. […] This tells us we should be looking for drugs that bind to that pocket and can serve the same purpose as the cryptochrome tail. […] We know now that we need to target that pocket to develop therapeutics that could shorten the clock for people with delayed sleep phase disorder.

• #2 Delayed sleep-wake phase disorder

  https://researchfeatures.com/delayed-sleep-wake-phase-disorder/

  Delayed sleep-wake phase disorder (DSWPD) is a circadian rhythm disorder, characterised by a late onset of sleep and wakefulness compared to conventional times or a night owl preference. […] The exact cause of DSWPD has remained elusive. Researchers have hypothesised that both genetic and environmental factors play a role in initiating and exacerbating this condition. […] Polymorphism in the circadian clock gene hPer3, human leukocyte antigen, and Clock are found to be associated with DSWPD onset and progression. […] A 2017 study published in Cell identified a gene involved in the circadian clock, CRY1, to play a role in DSWPD. […] A gain-of-function mutation leads to increased CRY1 protein expression and inhibition of target genes: Clock and BMAL1. […] Altogether, it is associated with increased period of molecular circadian rhythms in cells and delayed sleep onset.

• #2

  https://www.advocatehealth.com/health-services/sleep-medicine/delayed-sleep-phase-syndrome

  There are many causes of delayed sleep phase disorder, which are not entirely understood. Delayed sleep phase syndrome often runs in families. Environmental factors, such as late-night exposure to light, can also disrupt your circadian rhythm. […] Individuals with ADHD often exhibit symptoms of delayed sleep phase syndrome, such as difficulty falling asleep at conventional bedtimes and excessive daytime sleepiness. […] Treatment for delayed sleep phase syndrome aims to shift your sleep-wake cycle to more conventional times. A sleep specialist will help you come up with effective strategies to improve your sleep pattern.

• #3 Delayed sleep phase disorder – Wikipedia

  https://en.wikipedia.org/wiki/Delayed_sleep_phase_disorder

  People with normal circadian systems can generally fall asleep quickly at night if they slept too little the night before. Falling asleep earlier will in turn automatically help to advance their circadian clocks due to decreased light exposure in the evening. In contrast, people with DSPD have difficulty falling asleep before their usual sleep time, even if they are sleep-deprived.

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