Just Let Me Sleep in: Identifying and Treating Delayed Sleep Phase Disorder in Adolescents.

Individuals with delayed sleep phase disorder (DSPD) are unable to naturally fall asleep and awake at conventional times; for this reason, DSPD is often mistaken for insomnia. However, unlike many patients with insomnia, those with DSPD struggle to get up at appropriate times. DSPD is associated with school refusal, academic difficulties, and lower employment rate. DSPD in youth has prevalence as high as 16%, and is often comorbid with other psychiatric disorders. Treatments include appropriate light exposure during the day, melatonin use, developing an evening routine that minimizes arousal-increasing activities, and gradually shifting sleep-wake times toward more functional ones.

Circadian Rhythm Sleep-Wake Disorders in Older Adults.

The timing, duration, and consolidation of sleep result from the interaction of the circadian timing system with a sleep-wake homeostatic process. When aligned and functioning optimally, this allows for wakefulness throughout the day and a long consolidated sleep episode at night. Changes to either the sleep regulatory process or how they interact can result in an inability to fall asleep at the desired time, difficulty remaining asleep, waking too early, and/or difficulty remaining awake throughout the day. This mismatch between the desired timing of sleep and the ability to fall asleep and remain asleep is a hallmark of a class of sleep disorders called the circadian rhythm sleep-wake disorders. In this updated article, we discuss typical changes in the circadian regulation of sleep with aging; how age influences the prevalence, diagnosis, and treatment of circadian rhythm sleep disorders; and how neurologic diseases in older patient impact circadian rhythms and sleep.

Treatment of Circadian Rhythm Sleep-Wake Disorders.

Circadian rhythm sleep-wake disorders (CRSWDs) are a distinct class of sleep disorders caused by alterations to the circadian time-keeping system, its entrainment mechanisms, or a mismatch between the endogenous circadian rhythm and the external environment. The main clinical manifestations are insomnia and excessive daytime sleepiness that often lead to clinically meaningful distress or cause mental, physical, social, occupational, educational, or other functional impairment. CRSWDs are easily mistaken for insomnia or early waking up, resulting in inappropriate treatment. CRSWDs can be roughly divided into two categories, namely, intrinsic CRSWDs, in which sleep disturbances are caused by alterations to the endogenous circadian rhythm system due to chronic changes in the regulation or capture mechanism of the biological clock, and extrinsic circadian rhythm sleep-wake disorders, in which sleep disorders, such as jet lag or shift-work disorder, result from environmental changes that cause a mismatch between sleep-wakefulness times and internal circadian rhythms. Sleep diaries, actigraphy, and determination of day and night phase markers (dim light melatonin onset and core body temperature minimum) have all become routine diagnostic methods for CRSWDs. Common treatments for CRSWD currently include sleep health education, time therapy, light therapy, melatonin, and hypnotic drug therapy. Here, we review the progress in the epidemiology, etiology, diagnostic evaluation, diagnostic criteria, and treatment of intrinsic CRSWD, with emphasis on the latter, in the hope of bolstering the clinical diagnosis and treatment of CRSWDs.

Workshop report. Circadian rhythm sleep-wake disorders: gaps and opportunities.

This White Paper presents the results from a workshop cosponsored by the Sleep Research Society (SRS) and the Society for Research on Biological Rhythms (SRBR) whose goals were to bring together sleep clinicians and sleep and circadian rhythm researchers to identify existing gaps in diagnosis and treatment and areas of high-priority research in circadian rhythm sleep-wake disorders (CRSWD). CRSWD are a distinct class of sleep disorders caused by alterations of the circadian time-keeping system, its entrainment mechanisms, or a misalignment of the endogenous circadian rhythm and the external environment. In these disorders, the timing of the primary sleep episode is either earlier or later than desired, irregular from day-to-day, and/or sleep occurs at the wrong circadian time. While there are incomplete and insufficient prevalence data, CRSWD likely affect at least 800,000 and perhaps as many as 3 million individuals in the United States, and if Shift Work Disorder and Jet Lag are included, then many millions more are impacted. The SRS Advocacy Taskforce has identified CRSWD as a class of sleep disorders for which additional high-quality research could have a significant impact to improve patient care. Participants were selected for their expertise and were assigned to one of three working groups: Phase Disorders, Entrainment Disorders, and Other. Each working group presented a summary of the current state of the science for their specific CRSWD area, followed by discussion from all participants. The outcome of those presentations and discussions are presented here.

Just Let Me Sleep in: Identifying and Treating Delayed Sleep Phase Disorder in Adolescents.

Individuals with delayed sleep phase disorder (DSPD) are unable to naturally fall asleep and awake at conventional times; for this reason, DSPD is often mistaken for insomnia. However, unlike many patients with insomnia, those with DSPD struggle to get up at appropriate times. DSPD is associated with school refusal, academic difficulties, and lower employment rate. DSPD in youth has prevalence as high as 16%, and is often comorbid with other psychiatric disorders. Treatments include appropriate light exposure during the day, melatonin use, developing an evening routine that minimizes arousal-increasing activities, and gradually shifting sleep-wake times toward more functional ones.

Effect of Suvorexant vs Placebo on Total Daytime Sleep Hours in Shift Workers: A Randomized Clinical Trial.

Importance: Many shift workers have difficulty sleeping during the daytime owing to an inappropriately timed circadian drive for wakefulness. Objective: To determine whether a dual hypocretin receptor antagonist would enable shift workers to have more daytime sleep. Design, Setting, and Participants: This double-blind, placebo-controlled randomized clinical trial included 2 weeks of baseline data and 3 weeks of intervention data, from March 2016 to December 2018. Individuals were recruited through poster advertisements in the broader San Francisco Bay area in California. From an initial voluntary recruitment cohort of 38 shift workers, 19 individuals with self-reported difficulty sleeping during the daytime following night work shift were included. Data were analyzed from Janaury to March 2019. Interventions: 1 week of 10 mg suvorexant or placebo, titrated upward to 20 mg suvorexant or placebo for 2 additional weeks. Main Outcomes and Measures: Objective (ie, actigraphy) and subjective (ie, sleep logs) measures of sleep. Results: Among 19 participants who completed the study (mean [SD] age, 37.7 [11.1] years; 13 [68%] men), 8 participants (42%) were assigned to the suvorexant group and 11 participants (58%) were assigned to the placebo group. Compared with individuals in the placebo group, individuals in the suvorexant group increased their objective total sleep time by a mean (SE) of 1.04 (0.53) hours (P = .05) at the end of 1 week of 10-mg doses and by 2.16 (0.75) hours (P = .004) by the end of the 2 weeks of 20-mg doses. Subjective sleep was similarly improved as, compared with the placebo group, individuals in the suvorexant group increased their subjective total sleep time by a mean (SE) of 2.08 (0.47) hours (P < .001) at the end of 1 week of 10-mg doses and by 2.97 (0.56) hours (P < .001) by the end of the 2 weeks of 20-mg doses. Physician ratings of daytime sleep aligned with these measures, as there was no change in the placebo group and a much improved change in the suvorexant group. No adverse events were reported in the suvorexant group. Conclusions and Relevance: This pilot study found that the use of a dual hypocretin receptor antagonist in shift workers under real-world conditions resulted in more than 2 extra hours of daytime sleep per episode. Future research should confirm this pilot finding in a larger sample size and examine whether, over the long term, use of this medication has a concomitant improvement in medical and psychiatric health as well as workplace performance and safety. Trial Registration: ClinicalTrials.gov Identifier: NCT02491788.

Sleep coaching: non-pharmacological treatment of non-restorative sleep in Austrian railway shift workers.

Sleep coaching by Holzinger & Klösch™ is a new, Gestalt therapy-based holistic approach to non-pharmacological treatment of non-restorative sleep. It includes psychotherapeutic aspects which enable participants to improve their sleep quality by developing their own coping strategies as a daily routine. Dream work and relaxation techniques are also part of the programme. The aim of this study was to measure the effectiveness of a two-day sleep coaching seminar on sleep quality, daytime sleepiness, and work and life quality in shift workers employed in an Austrian railway company (Österreichische Bundesbahnen, ÖBB). Thirty shift workers (28 male; mean age=24±45.90, age range 24-56 years) answered the same survey before and six months after the seminar (baseline and follow-up) containing items of the Pittsburgh Sleep Quality Index (PSQI) and the Epworth Sleepiness Scale (ESS), their chronotype, personality factors, and burnout risk factors. The baseline findings in this group were compared with those of non-completers (who did not take the follow-up survey) (N=154) to see if the two groups differed significantly enough to create a bias among completers (who took the follow-up survey as well). Groups differed significantly in burnout levels as well as sleep duration, but not in the distribution of critical PSQI and ESS values. The two-day sleep coaching seminar resulted in a significant improvement in total PSQI score and subjective sleep quality and in a significant reduction in diurnal fatigue, sleep latency, and daytime sleepiness. Nevertheless, more research with a larger sample and a longitudinal design is needed to establish the long-term effects of sleep coaching.

Circadian Rhythm Sleep-Wake Disorders in Older Adults.

The timing, duration, and consolidation of sleep result from the interaction of the circadian timing system with a sleep-wake homeostatic process. When aligned and functioning optimally, this allows wakefulness throughout the day and a long consolidated sleep episode at night. Mismatch between the desired timing of sleep and the ability to fall and remain asleep is a hallmark of the circadian rhythm sleep-wake disorders. This article discusses changes in circadian regulation of sleep with aging; how age influences the prevalence, diagnosis, and treatment of circadian rhythm sleep-wake disorders; and how neurologic diseases in older patients affect circadian rhythms and sleep.

Trastorno de retraso de la fase del sueño y del despertar. Síndrome de retraso de fase / Delayed sleep wake phase disorder (DSWPD)

El trastorno de retraso de la fase del sueño y del despertar o síndrome de retraso de fase (SRF) es la alteración del ritmo circadiano de sueño más frecuente y suele manifestarse en la adolescencia. Se caracteriza por un retraso estable, habitualmente de más de dos horas, del inicio y del final del sueño respecto a los horarios convencionales. Clínicamente los pacientes presentan insomnio a la hora de acostarse, con gran dificultad para levantarse por la mañana en la hora deseada. Entre semana, debido a las obligaciones escolares o sociales, los niños con SRF duermen pocas horas, generándose una privación crónica de sueño que se manifestará con somnolencia diurna, fatiga, falta de atención, afectación del rendimiento escolar o absentismo escolar. Característicamente, el fin de semana o durante las vacaciones, cuando están libres de horarios, retrasan el sueño, siendo este de características normales y levantándose descansados. Es importante realizar un diagnóstico precoz para iniciar un tratamiento temprano que minimice las consecuencias del SRF. Por la imposibilidad de seguir unos horarios regulares de estudio ni de trabajo, son jóvenes a los que se califica de noctámbulos o de vagos, a pesar de sus esfuerzos repetidos por adaptarse a unos horarios convencionales, lo que aboca en altos índices de depresión, ansiedad y abuso de sustancias. El retraso de fase de sueño se confirma mediante las agendas de sueño, la actigrafía y los marcadores de fase circadianos. La higiene del sueño, la cronoterapia, la fototerapia y la administración de melatonina son los posibles tratamientos del SRF (AU)

Delayed sleep wake phase disorder (DSWPD) or delayed sleep phase disorder is the most frequent circadian rhythm sleep disorder and is commonly seen in adolescents. DSWPD is characterized by habitual by sleep onset and wake times that are usually delayed more than two hours relative to conventional sleep-wake times. Clinically, affected subjects experience difficulty falling asleep and arising at socially acceptable wake time. Enforced conventional wake times (during the school or working days), may result in chronically insufficient sleep manifested as excessive daytime sleepiness, fatigue, repetitive school absences with negative impact on their attention and academic performance. When allowed to follow their preferred schedule (during the weekends or vacation periods), the patient’s timing of sleep is delayed with normal and restoring sleep. It is very important to make an early diagnosis to initiate treatments that minimize consequences of DSWPD. Although their repetitive attempts to adapt to conventional times, their difficulties to maintain regular school or work timings leads these adolescents to be seen as lazy and not motivated, which usually results in an increase in mood disorders and drug abuse. Delay sleep phase is demonstrated by sleep log, actigraphy monitoring and in the timing of other circadian rhythms. Sleep hygiene, chronotherapy, bright light therapy or melatonin administration are the most habitual treatment of the DSWPD (AU)

Sleepiness, sleep, and use of sleepiness countermeasures in shift-working long-haul truck drivers.

Driver sleepiness is a prevalent phenomenon among professional drivers working unconventional and irregular hours. For compromising occupational and traffic safety, sleepiness has become one of the major conundrums of road transportation. To further elucidate the phenomenon, an on-road study canvassing the under-explored relationship between working hours and sleepiness, sleep, and use of sleepiness countermeasures during and outside statutory rest breaks was conducted. Testing the association between the outcomes and working hours, generalized estimating equations models were fitted on a data collected from 54 long-haul truck drivers (mean 38.1 ± 10.5 years, one female) volunteering in the 2-week study. Unobtrusive data-collection methods applied under naturalistic working and shift conditions included the Karolinska Sleepiness Scale (KSS) measuring sleepiness, a combination of actigraphy and sleep-log measuring sleep, and self-report questionnaire items incorporated into the sleep-log measuring the use of sleepiness countermeasures during and outside statutory rest breaks. Drivers' working hours were categorized into first and consecutive night, morning and day/evening shifts based on shift timing. The results reveal severe sleepiness (KSS≥7) was most prevalent on the first night (37.8%) and least on the morning (10.0%) shifts. Drivers slept reasonably well prior to duty hours, with main sleep being longest prior to the first night (total sleep time 7:21) and shortest prior to the morning (total sleep time 5:43) shifts. The proportion of shifts whereby drivers reported using at least one sleepiness countermeasure outside statutory rest breaks was approximately 22% units greater for the night than the non-night shifts. Compared to the day/evening shifts, the odds of severe sleepiness were greater only on the first night shifts (OR 6.4-9.1 with 95% confidence intervals, depending on the statistical model), the odds of insufficient daily sleep were higher especially prior to the consecutive night shifts (OR 3.5 with 95% confidence intervals), and the odds of using efficient sleepiness countermeasures outside statutory rest breaks were greater on the first as well as consecutive night shifts (OR 4.0-4.6 with 95% confidence intervals). No statistically significant association was found between shift type and use of efficient sleepiness countermeasures during statutory rest breaks. In all, the findings demonstrate marked differences in the occurrence of severe sleepiness at the wheel, sleep preceding duty hours, and the use of sleepiness countermeasures between different shift types. In addition, although drivers slept reasonably well in connection with different shift types, the findings imply there is still room for improvement in alertness management among this group of employees.

Predictors of shift work disorder among nurses: a longitudinal study.

BACKGROUND: Shift work is associated with sleep problems and impaired health. The main aim of the present study was to explore predictors of developing shift work disorder (SWD) among Norwegian nurses using a longitudinal design. METHODS: A total of 1533 nurses participating in a survey on shift work, sleep and health responded to questionnaires at baseline and at follow-up about two years later. SWD was defined as problems of excessive sleepiness and/or complaints of insomnia related to the work schedule. RESULTS AND CONCLUSIONS: There was a significant reduction (p < 0.001) in the prevalence of SWD from baseline to follow-up, from 35.7% to 28.6%. Logistic regression analyses showed significant risks of having SWD at follow-up and the following variables measured at baseline: number of nights worked the last year (OR = 1.01, 95% CI = 1.01-1.02), having SWD (OR = 5.19, 95% CI = 3.74-7.20), composite score on the Epworth Sleepiness Scale (OR = 1.08, 95% CI = 1.04-1.13), use of melatonin (OR = 4.20, 95% CI = 1.33-13.33), use of bright light therapy (OR = 3.10, 95% CI 1.14-8.39), and symptoms of depression measured by the Hospital Anxiety and Depression Scale (OR = 1.07, 95% CI = 1.00-1.14). In addition, leaving night work between baseline and follow-up was associated with a significantly reduced risk of SWD at follow-up (OR = 0.12, 95% CI = 0.07-0.22).

Circadian rhythm disorders among adolescents: assessment and treatment options.

Delayed sleep phase disorder (DSPD) - a circadian rhythm sleep disorder - is most commonly seen in adolescents. The differential diagnosis between DSPD and conventional psychophysiological insomnia is important for correct therapeutic intervention. Adolescent DSPD sleep duration is commonly 9 hours or more. Depression may be comorbid with DSPD. DSPD has a negative impact on adolescent academic performance. DSPD treatments include bright light therapy, chronotherapeutic regimens, and administration of melatonin as a chronobiotic (as distinct from a soporific). Attention to non-photic and extrinsic factors including healthy sleep parameters is also important to enable better sleep and mood outcomes in adolescents.

Shift work disorder in nurses--assessment, prevalence and related health problems.

BACKGROUND: This study investigates the prevalence of symptoms of shift work disorder in a sample of nurses, and its association to individual, health and work variables. METHODOLOGY/PRINCIPAL FINDINGS: We investigated three different shift work disorder assessment procedures all based on current diagnostic criteria and employing symptom based questions. Crude and adjusted logistic regression analyses were performed with symptoms of shift work disorder as the dependent variable. Participants (n = 1968) reported age, gender, work schedule, commuting time, weekly work hours, children in household, number of nights and number of shifts separated by less than 11 hours worked the last year, use of bright light therapy, melatonin and sleep medication, and completed the Bergen Insomnia Scale, Epworth Sleepiness Scale, Global Sleep Assessment Questionnaire, Diurnal Scale, Revised Circadian Type Inventory, Dispositional Resilience (Hardiness) Scale--Revised, Fatigue Questionnaire, questions about alcohol and caffeine consumption, as well as the Hospital Anxiety and Depression Scale. CONCLUSIONS/SIGNIFICANCE: Prevalence rates of symptoms of shift work disorder varied from 32.4-37.6% depending on the assessment method and from 4.8-44.3% depending on the work schedule. Associations were found between symptoms of shift work disorder and age, gender, circadian type, night work, number of shifts separated by less than 11 hours and number of nights worked the last year, insomnia and anxiety. The different assessment procedures yielded similar results (prevalence and logistic regression analyses). The prevalence of symptoms indicative of shift work disorder was high. We argue that three symptom-based questions used in the present study adequately assess shift work disorder in epidemiological studies.

Night work and health status of nurses and midwives. cross-sectional study.

BACKGROUND: The aim of this study was to assess the association between night shift work and the prevalence of diseases and conditions among nurses and midwives. MATERIAL AND METHODS: The study included 725 subjects (354 working on night shifts and 371 working only during the day). The data were collected via an interview based on the "Standard Shiftwork Index". We analyzed the frequency of diseases and conditions and the relative risk expressed as the odds ratio (adjusted for important confounding factors). RESULTS: The most common diseases in the study population were chronic back pain (47.2%), hypertension (24.5%) and thyroid diseases (21.2%). We found no statistically significant increased relative risk of any diseases and conditions among the night shift nurses, compared to the day shift ones. The duration of the work performed on night shifts was significantly associated with the relative risk of thyroid diseases--increased almost two times in the women working for 15 or more years in such system (p for trend: 0.031). The analysis showed the significantly increased (more than eight times higher) relative risk of feet swelling in the women with 8 or more night duties per month, compared to the women having fewer night shifts. CONCLUSIONS: We did not observe a higher frequency of diseases in the night shift nurses, compared to the day shift nurses. These results may be related to the so-called "Healthy Worker Effect". There is a need for further long-term observational studies in the populations of nurses.

Chronobiological disorders: current and prevalent conditions.

In recent decades, the hectic lifestyle of industrialized societies has wrought its effects on the quality of sleep, and these effects are evidenced by a profusion of sleep-related disorders. Regular exposure to artificial light, coupled with social and economic pressures have shortened the time spent asleep. Otherwise, Circadian Rhythm Sleep Disorders are characterized by desynchronization between the intrinsic circadian clock and the extrinsic cycles of light/dark and social activities. This desynchronization produces excessive sleepiness and insomnia. The International Classification of Sleep Disorders describes nine sleep disorders under the category of Circadian Rhythm Sleep Disorders. Currently, this diagnosis is made based on the patient's history, a sleep log alone, or the sleep logs and actigraphy conducted for at least 7 days. This review contains an overview of current treatment options, including chronotherapy, timed bright light exposure, and administration of exogenous melatonin.

Shift work disorder among oil rig workers in the North Sea.

STUDY OBJECTIVES: Shift work disorder (SWD) is a circadian rhythm sleep disorder caused by work hours during the usual sleep period. The main symptoms are excessive sleepiness and insomnia temporally associated with the working schedule. The aim of the present study was to examine SWD among shift workers in the North Sea. DESIGN AND PARTICIPANTS: A total of 103 shift workers (2 weeks on 7 nights/7days, 12-h shifts, 4 weeks off), mean age 39.8 years, working at an oil rig in the North Sea responded to a questionnaire about SWD. They also completed the Pittsburgh Sleep Quality Index, Bergen Insomnia Scale, Epworth Sleepiness Scale, Composite Morningness Questionnaire, Subjective Health Complaint Inventory, Demand/Control, and Instrumental Mastery Oriented Coping (based on the Utrecht Coping list). Most of these instruments were administered during the first day of the 2-week working period, thus reflecting symptoms and complaints during the 4-week non-work period. The shift workers were also compared to day workers at the oil rig. RESULTS: Twenty-four individuals were classified as suffering from SWD, yielding a prevalence for SWD of 23.3%. During the 4-week non-work period, individuals with SWD reported significantly poorer sleep quality, as measured by the Pittsburgh Sleep Quality Index, and more subjective health complaints than individuals not having SWD. There were no differences between the 2 groups in sleepiness, insomnia, circadian preference, psychological demands, or control. Individuals with SWD reported significantly lower scores on coping. The reports of shift workers without SWD were similar to those of day workers regarding sleep, sleepiness, subjective health complaints, and coping. CONCLUSIONS: The prevalence of SWD was relatively high among these shift workers. Individuals with SWD reported poorer sleep quality and more subjective health complaints in the non-work period than shift workers not having SWD.

Sleep and delirium in ICU patients: a review of mechanisms and manifestations.

Sleep deprivation and delirium are conditions commonly encountered in intensive care unit patients. Sleep in these patients is characterized by sleep fragmentation, an increase in light sleep, and a decrease of both slow wave sleep and rapid eye movement sleep. The most common types of delirium in this population are hypoactive and mixed-type. Knowledge about the mechanisms of sleep and delirium has evolved over time, but these phenomena are not yet well understood. What is known, however, is that different areas in the brainstem transmit information to the thalamus and cortex necessary for sleep-wake regulation. Delirium is related to an imbalance in the synthesis, release, and inactivation of some neurotransmitters, particularly acetylcholine and dopamine. The relationship between sleep deprivation and delirium has been studied for many years and has been viewed as reciprocal. The link between them may be ascribed to shared mechanisms. An imbalance in neurotransmitters as well as alteration of melatonin production may contribute to the pathogenesis of both phenomena. A better understanding of the mechanisms and factors that contribute to sleep deprivation and delirium can guide the development of new methods and models for prevention and treatment of these problems and consequently improve patient outcomes.

Circadian rhythm sleep disorders: part I, basic principles, shift work and jet lag disorders. An American Academy of Sleep Medicine review.

OBJECTIVE: This the first of two articles reviewing the scientific literature on the evaluation and treatment of circadian rhythm sleep disorders (CRSDs), employing the methodology of evidence-based medicine. In this first part of this paper, the general principles of circadian biology that underlie clinical evaluation and treatment are reviewed. We then report on the accumulated evidence regarding the evaluation and treatment of shift work disorder (SWD) and jet lag disorder (JLD). METHODS: A set of specific questions relevant to clinical practice were formulated, a systematic literature search was performed, and relevant articles were abstracted and graded. RESULTS: A substantial body of literature has accumulated that provides a rational basis the evaluation and treatment of SWD and JLD. Physiological assessment has involved determination of circadian phase using core body temperature and the timing of melatonin secretion. Behavioral assessment has involved sleep logs, actigraphy and the Morningness-Eveningness Questionnaire (MEQ). Treatment interventions fall into three broad categories: 1) prescribed sleep scheduling, 2) circadian phase shifting ("resetting the clock"), and 3) symptomatic treatment using hypnotic and stimulant medications. CONCLUSION: Circadian rhythm science has also pointed the way to rational interventions for the SWD and JLD, and these treatments have been introduced into the practice of sleep medicine with varying degrees of success. More translational research is needed using subjects who meet current diagnostic criteria.

Recent advances in the treatment and management of excessive daytime sleepiness.

Excessive daytime sleepiness (EDS) is a prevalent complaint among patients in psychiatric care. Patients with conditions of EDS have often been misdiagnosed with depression due to their complaints of lack of energy, poor concentration, memory disturbance, and a reduced interest in life. Impaired alertness associated with EDS can be detrimental to a person's quality of life by causing decreased work performance, self-consciousness, low self esteem, and social isolation. Excessive sleepiness is also associated with various health problems, comorbid medical and psychiatric conditions, and fatal accidents occurring after the driver has fallen asleep at the wheel. Contributing factors leading to EDS range from insufficient sleep hours to central nervous system-mediated debilitating hypersomnolence. Circadian rhythm disorders, sleep disorders such as obstructive sleep apnea and narcolepsy, and medications that cause sleepiness may also contribute to symptoms of EDS. Recognition of the symptoms of sleep deprivation is essential, as many such patients do not have a clear awareness of their own sleepiness. Treatment options, depending upon the condition, include light therapy or appropriate airway management techniques such as nasal continuous positive airway pressure (CPAP). Occasionally, wakefulness-promoting medications are necessary, particularly in patients with narcolepsy. In this expert roundtable supplement, Stephen P. Duntley, MD, reviews the definition and prevalence of EDS and discusses the contributing factors and consequences of daytime sleepiness. Next, Richard K. Bogan, MD, FCCP, gives an overview of the differential diagnosis of EDS and the assessment tools available for identifying sleepiness in symptomatic patients. Finally, Mary B. O'Malley, MD, PhD, reviews treatment of EDS, including counseling on sleep hygiene and duration of sleep, mechanical treatments, bright-light therapy, and wake-promoting medications.

Clinical management of delayed sleep phase disorder.

Delayed Sleep Phase Disorder is a circadian rhythm disorder that results in a late timed sleep pattern. Individuals have difficulty falling asleep at a conventional hour and difficulty waking in the morning. We discuss the contributing factors and consequences of a delayed sleep phase and describe treatment approaches. These include therapies to phase change the delayed sleep circadian rhythm such as morning bright light exposure, exogenous melatonin administration, and chronotherapy as well as some behavioral strategies.