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The Pineal Gland and Melatonin
Published in George H. Gass, Harold M. Kaplan, Handbook of Endocrinology, 2020
Jerry Vriend, Nancy A.M. Alexiuk
Studies of circulating melatonin rhythms in humans suggest that melatonin may be useful in treating disorders of biological rhythms.541 Following the report of Marczynski and coworkers542 that it induced sleep in cats, melatonin has been linked to sleep mechanisms. Melatonin administration may result in sleep in humans543 and has been reported to synchronize sleep cycles in a patient lacking a pineal gland544 and in a blind individual.545 A melatonin-induced alleviation of “jet lag” and “shift workers” syndrome has been confirmed in several recent studies,546–549 however, it has been questioned whether this effect will eventually have any practical significance.550 Melatonin administration could be useful in the treatment of delayed sleep phase syndrome, particularly in older individuals in whom the secretion of melatonin is reduced.551
What Actually Is Sleep?
Published in Zippi Dolev, Mordechai Zalesch, Judy Kupferman, Sleep and Women's Health, 2019
Zippi Dolev, Mordechai Zalesch, Judy Kupferman
For one affected by delayed sleep phase syndrome, the sense of tiredness arrives only between 1 a.m. and 3 a.m., if not later. As a result, it is difficult to wake up in the morning for work or school. One feels tired throughout most of the day and has a deep desire to sleep. The sleep deficit is overcome on weekends.
Disorders
Published in Jonathan P Rogers, Cheryl CY Leung, Timothy RJ Nicholson, Pocket Prescriber Psychiatry, 2019
Jonathan P Rogers, Cheryl CY Leung, Timothy RJ Nicholson
Light therapy is a treatment for delayed sleep phase syndrome. Requires exposure to bright light for 30–120 min depending on properties of the lamp.
Understanding the role of chronopharmacology for drug optimization: what do we know?
Published in Expert Review of Clinical Pharmacology, 2023
Akio Fujimura, Kentaro Ushijima
Delayed sleep phase syndrome (DSPS) is a disease of circadian rhythm. Sleep onset and offset are delayed in patients with DSPS, so it is difficult to adjust their sleep-wake cycles to fit a normal daily schedule. Bezafibrate is a hypolipidemic drug that is a ligand of peroxisome proliferator-activated receptor α (PPARα) and regulates the expression of lipid metabolism-associated genes. An animal study showed that bezafibrate induces the advanced phase of locomotor activity rhythm and 24-h food intake rhythm [94,95]. The advanced circadian phase induced by bezafibrate can be explained by the finding that PPARα is a positive regulator of expression of Bmal1 [96]. Activation of PPARα leads to an elevated BMAL1 protein level, which, in turn, enhances the functions of clock output systems. Therefore, it is anticipated that ligands of PPARα, including bezafibrate, would be promising treatments for DSPS.
The circadian preferences in the context of sociodemographic indicators and lifestyle
Published in Chronobiology International, 2022
Denisa Manková, Jan Novák, Petr Sedlak, Eva Andrlíková (Farkova)
Circadian preference is influenced by many variables. Heredity (Klei et al. 2005), hormonal changes, increasingly revealing genetics (Merikanto et al. 2021; von Schantz 2017), as well as socio-psycho-environmental phenomena (Maierova et al. 2016; Roenneberg and Merrow 2007) are involved in these changes. Many studies proved that circadian types change during lifespan. Children tend to be morning types. Due to changes in the homeostatic (slower accumulation of homeostatic sleep pressure) and circadian (a tendency to have a longer intrinsic period compared to adults) systems, Delayed sleep phase syndrome (DSPS) occurs during adolescence. DSPS is characterized by a later tendency to go to sleep and a chronic inability to fall asleep and wake at the desired clock time (Crowley et al. 2007). The breaking point for the M/E change is later in boys – 17.2 years than girls – 15.7 (Randler et al. 2017). The return to the morning type takes place from middle adulthood onwards, with a significant predominance in the elderly (for review, see Adan et al. 2012). In contrast to these results, other studies showed that individual chronotypes in middle-aged people have a normal or almost normal distribution (Roenneberg and Merrow 2007). Specifically, in the circadian preferences measured by MEQ, this shift occurs after changing the original cut-off scores to the new (Paine et al. 2006; Taillard et al. 2004). There is no complete agreement among scientists on the representation of sex in individual circadian preferences.
Effects of chronotherapy on circadian rhythm and ADHD symptoms in adults with attention-deficit/hyperactivity disorder and delayed sleep phase syndrome: a randomized clinical trial
Published in Chronobiology International, 2021
Emma van Andel, Denise Bijlenga, Suzan W. N. Vogel, Aartjan T. F. Beekman, J. J. Sandra Kooij
A biomarker for the internal circadian rhythm is the Dim-Light Melatonin Onset (DLMO), indicating the time when endogenous salivary melatonin reaches a threshold of 3 pg/ml (Lewy and Sack 1989). Sleep initiation in adults with ADHD occurs on average 2.5 h after the DLMO (Bijlenga et al. 2013b). A delayed circadian rhythm is associated with sleep-onset problems when going to bed at a socially accepted earlier time, and shorter sleep duration on nights before work days, when one needs to get up early relative to one’s circadian rhythm. According to the Diagnostic and Statistical Manual of Mental Disorders (5th Edition; DSM-5), Delayed Sleep Phase Syndrome (DSPS) is diagnosed when a chronic delayed circadian rhythm is not caused by other disorders or substances, if the pattern persists for at least 6 months, and causes functional daytime impairments (American Psychiatric Association 2013). The prevalence of DSPS in our clinic has previously been estimated at 26% based on self-reports (Bijlenga et al. 2013a). However, it has not been systematically assessed and is likely an underestimation. Another one of our previous studies showed that 78% of adults with ADHD had a diagnosis of sleep-onset insomnia (SOI) and a delayed DLMO (Van Veen et al. 2010). SOI and DSPS are both used as indications for a delayed circadian rhythm (Bijlenga et al. 2019); so, the true prevalence of DSPS in adults with ADHD is considered to be close to 78%. This indicates a huge difference compared to the general population in which DSPS prevalence is estimated at 0.1–3.1% (Bijlenga et al. 2019).