Clinical characteristics of circadian rhythm sleep disorders

Decrease in Social Zeitgebers Is Associated With Worsened Delayed Sleep-Wake Phase Disorder: Findings During the Pandemic in Japan

BACKGROUND

Delay in sleep-wake rhythms was observed in the general population during the coronavirus disease 2019 (COVID-19) pandemic. Patients with delayed sleep-wake phase disorder (DSWPD) may have also experienced exacerbation of symptoms, but no studies have investigated this topic. In this study, we aimed to retrospectively examine the changes in symptoms of outpatients with DSWPD both before and during the pandemic and to identify the factors associated with the exacerbation of sleep-wake rhythms.

METHODS

We included outpatients with DSWPD aged 16 years or older who visited the outpatient clinic due to sleep disorders between January and September 2020. Decreased social zeitgebers was defined as a reduction of 50% or more in the frequency of commuting to school or work during the COVID-19 pandemic. The severity of DSWPD was assessed using the clinical global impressions - severity of illness (CGI-S) at two points: before and during the pandemic. We defined the worsened, unchanged, and improved groups as those whose CGI-S scores worsened by at least one point, remained unchanged, and improved by at least one point, respectively. Multivariate logistic regression analysis was performed to determine the factors associated with worsened DSWPD symptoms.

RESULTS

Sixty patients with DSWPD were eligible for this study. Even before the pandemic, patients who were unemployed or did not attend school tended to show more severe DSWPD symptoms. During the pandemic, 27 patients belonged to the worsened group; 28 patients, unchanged group; and 5 patients, improved group. Decreased social zeitgebers (odds ratio [OR] = 6.668, 95% confidence interval [CI]: 1.653-26.891, p < 0.05) and comorbid mood disorders (OR = 8.876, 95% CI: 1.714-45.974, p < 0.05) showed independent significant associations with the worsening of DSWPD symptoms.

CONCLUSIONS

During the pandemic, the symptoms of DSWPD tended to worsen. The obtained findings emphasize the importance of social zeitgebers, suggesting the need for external motivation in DSWPD treatment.

Attention-deficit hyperactivity disorder symptoms add risk to circadian rhythm sleep problems in depression and anxiety

BACKGROUND

Comorbid ADHD symptoms may partly account for circadian rhythm disturbances in depression and anxiety disorders.

METHODS

Self-reported sleep characteristics of 2090 participants in the Netherlands Study of Depression and Anxiety were assessed using the Munich Chronotype Questionnaire. We defined 3 groups: healthy controls (HC), persons with lifetime depression and/or anxiety disorders (LDA), and those with both LDA and high ADHD symptoms (LDA+ADHD), using the Conner's Adult ADHD Rating Scale.

RESULTS

Sleep characteristics were least favorable in the LDA+ADHD group. Important group differences between LDA+ADHD, LDA and HC were found for extremely late chronotype (12% vs. 5% vs. 3%; p<.001), sleep duration <6h (15% vs. 5% vs. 4%; p<.001), and for an indication of the Delayed Sleep Phase Syndrome (DSPS; 16% vs. 8% vs. 5%; p<.001). After adjustment for covariates, including depression and anxiety, presence of ADHD symptoms increased the odds ratio for late chronotype (OR=2.6; p=.003), indication of DSPS (OR=2.4; p=.002), and sleep duration <6h (OR=2.7; p=.007).

LIMITATIONS

ADHD conceptually overlaps with symptom presentation of depression and anxiety. We used a cross-sectional study design, and used self reported sleep characteristics.

CONCLUSIONS

High ADHD symptoms were associated with an increased rate of circadian rhythm sleep disturbances in an already at-risk population of people with depression and/or anxiety disorders. Circadian rhythm sleep disorders, as often seen in ADHD are not entirely due to any comorbid depression and/or anxiety disorder. Adequate treatment of such sleep problems is needed and may prevent serious health conditions in the long term.

Systematic evaluation of Axis-I DSM diagnoses in delayed sleep phase disorder and evening-type circadian preference

BACKGROUND

Alterations in circadian rhythms can have profound effects on mental health. High co-morbidity for psychiatric disorders has been observed in patients with circadian rhythm disorders, such as delayed sleep phase disorder (DSPD), and in those with an evening-type circadian preference. The aim of this study was to systematically determine the prevalence and type of Diagnostic and Statistical Manual of Mental Disorders fourth edition (DSM IV) Axis-I disorders in those with DSPD compared to evening-type controls.

METHODS

Forty-eight DSPD and 25 evening-type participants took part in this study. Sleep and wake parameters were assessed with actigraphy, diary and questionnaires (Pittsburgh Sleep Quality Index (PSQI) and Functional Outcomes of Sleep Questionnaire (FOSQ). Evening-type preference was defined by the Horne-Ostberg questionnaire. DSPD was determined by an interview according to International Classification of Sleep Disorders criteria. Current and past diagnoses of psychiatric disorders were assessed with a Structured Clinical Interview for DSM-IV disorders.

RESULTS

DSPD was associated with a later wake time, longer sleep time, higher PSQI score and lower Horne-Ostberg and FOSQ scores compared to evening-types. There were no significant differences in the prevalence or type of Axis-I disorders between those with DSPD or evening-type preference. Over 70% of participants met criteria for at least one past Axis-I disorder. Approximately 40% of both the DSPD and evening-types met criteria for a past diagnosis of mood, anxiety (most frequently phobia) or substance-use disorders. Evening types were more likely to have a past diagnosis of more than one Axis-I disorder.

CONCLUSIONS

These results highlight the important link between circadian rhythms and mental disorders. Specifically, an evening circadian chronotype regardless of DSPD status is associated with a risk for anxiety, depressive or substance-use disorders.

Therapeutics for Circadian Rhythm Sleep Disorders

The sleep-wake cycle is regulated by the interaction of endogenous circadian and homeostatic processes. The circadian system provides timing information for most physiological rhythms, including the sleep and wake cycle. In addition, the central circadian clock located in the suprachiasmatic nucleus of the hypothalamus has been shown to promote alertness during the day. Circadian rhythm sleep disorders arise when there is a misalignment between the timing of the endogenous circadian rhythms and the external environment or when there is dysfunction of the circadian clock or its entrainment pathways. The primary synchronizing agents of the circadian system are light and melatonin. Light is the strongest entraining agent of circadian rhythms and timed exposure to bright light is often used in the treatment of circadian rhythm sleep disorders. In addition, timed administration of melatonin, either alone or in combination with light therapy has been shown to be useful in the treatment of the following circadian rhythm sleep disorders: delayed sleep phase, advanced sleep phase, free-running, irregular sleep wake, jet lag and shift work.

The roles of melatonin and light in the pathophysiology and treatment of circadian rhythm sleep disorders

Normal circadian rhythms are synchronized to a regular 24 h environmental light-dark cycle, and the suprachiasmatic nucleus and the hormone melatonin have important roles in this process. Desynchronization of circadian rhythms, as occurs in chronobiological disorders, can produce severe disturbances in sleep patterns. According to the International Classification of Sleep Disorders, circadian rhythm sleep disorders (CRSDs) include delayed sleep phase syndrome, advanced sleep phase syndrome, non-24 h sleep-wake disorder, jet lag and shift-work sleep disorder. Disturbances in the circadian phase position of plasma melatonin levels have been documented in all of these disorders. There is compelling evidence to implicate endogenous melatonin as an important mediator in CRSD pathophysiology, although further research involving large numbers of patients will be required to clarify whether the disruption of melatonin secretion is a causal factor in CRSDs. In this Review, we focus on the use of exogenous melatonin and light therapy to treat the disturbed sleep-wake rhythms seen in CRSDs.

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.

Circadian rhythm sleep disorders: part II, advanced sleep phase disorder, delayed sleep phase disorder, free-running disorder, and irregular sleep-wake rhythm. An American Academy of Sleep Medicine review

OBJECTIVE

This the second 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. We herein report on the accumulated evidence regarding the evaluation and treatment of Advamced Sleep Phase Disorder (ASPD), Delayed Sleep Phase Disorder (DSPD), Free-Running Disorder (FRD) and Irregular Sleep-Wake Rhythm ISWR).

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 CRSDs. 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 CRSDs 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.

Circadian rhythm sleep disorders: characteristics and entrainment pathology in delayed sleep phase and non-24-h sleep-wake syndrome

This paper presents a clinical review of delayed sleep phase syndrome (DSPS) and non-24-h sleep-wake syndrome (non-24). These syndromes seem to be common and under-recognized in society, not only in the blind, but also typically emerging during adolescence. Both types of syndrome can appear alternatively or intermittently in an individual patient. Psychiatric problems are also common in both syndromes. DSPS and non-24 could share a common circadian rhythm pathology in terms of clinical process and biological evidence. The biological basis is characterized by a longer sleep period, a prolonged interval from the body temperature nadir-to-sleep offset, a relatively advanced temperature rhythm, lower sleep propensity after total sleep deprivation, and higher sensitivity to light than in normal controls. There are multiple lines of evidence suggesting dysfunctions at the behavioral, physiological and genetic levels. Treatment procedures and prevention of the syndromes require further attention using behavioral, environmental, and psychiatric approaches, since an increasing number of patients in modern society suffer from these disorders.

A clinical approach to circadian rhythm sleep disorders

Circadian rhythm sleep disorders are characterized by complaints of insomnia and excessive sleepiness that are primarily due to alterations in the internal circadian timing system or a misalignment between the timing of sleep and the 24-h social and physical environment. In addition to physiological and environmental factors, maladaptive behaviors often play an important role in the development of many of the circadian rhythm sleep disorders. This review will focus on the clinical approach to the diagnosis and management of the various circadian rhythm sleep disorders, including delayed sleep phase disorder, advanced sleep phase disorder, non-entrained type, irregular sleep-wake rhythm, shift work sleep disorder and jet lag disorder. Diagnostic tools such as sleep diaries and wrist activity monitoring are often useful in confirming the diagnosis. Because behavioral and environmental factors often are involved in the development of these conditions, a multimodal approach is usually necessary. Interventions include sleep hygiene education, timed exposure to bright light as well as avoidance of bright light at the wrong time of the day and pharmacologic approaches, such as melatonin. However, it should be noted that the use of melatonin is not an FDA-approved indication for the treatment of circadian rhythm sleep disorders.

Circadian rhythm sleep disorders

Humans exhibit endogenous circadian rhythms that are regulated by the master circadian clock of the body, the suprachiasmatic nucleus. These endogenous circadian rhythms are aligned to the outside world by social and environmental cues. Circadian rhythm sleep disorders (CRSD) occur when there is an alteration of the internal timing mechanism or a misalignment between sleep and the 24-h social and physical environment. CRSD are often underrecognized yet should be considered in the differential of patients presenting with symptoms of insomnia and/or hypersomnia. Because behavioral and environmental factors often are involved in the development and maintenance of these conditions, a multimodal treatment approach of behavioral and/or pharmacologic approaches is usually required to synchronize a patient's circadian rhythm to the 24-h environment, consolidate sleep, and improve alertness. Rapid advances in our understanding of the physiologic, cellular, and molecular basis of circadian rhythm and sleep regulation will likely lead to improved diagnostic tools and treatments for CRSD.

Neurobiology of circadian rhythm sleep disorders

To adapt to a 24-hour environment, nearly all organisms, from mammals to single-celled organisms, have developed endogenous mechanisms that generate nearly 24-hour (circadian) rhythms in physiology and behavior, the most notable being that of the daily cycles of sleep and wake. Disruption of these circadian rhythms is often accompanied by disorders of sleep and wakefulness. With the recent advances in the molecular biology that underlies the development and maintenance of these rhythms, the pathophysiology behind circadian rhythm sleep disorders is becoming better understood.

Circadian Rhythm Sleep Disorders

Individuals who have circadian rhythm sleep disorders present with symptoms of insomnia or excessive sleepiness and complain of an inability to sleep at their desired time. Although the primary etiology of these disorders is a misalignment between the endogenous circadian clock and the external environment, social and behavioral factors can also play important roles in perpetuating or exacerbating these disorders. Currently, the management of circadian rhythm disorders is limited to the use of bright light and melatonin to realign the circadian clock with the desired sleep time.However, as the understanding of the physiologic and genetic basis of sleep and circadian rhythm regulation advances, even more practical and effective treatments should become available.

Behavioral profile of rats submitted to session 1-session 2 in the elevated plus-maze during diurnal/nocturnal phases and under different illumination conditions

The elevated plus-maze (EPM) model usually employs nocturnal species (e.g. rats and mice) and the tests are almost exclusively performed during the diurnal phase (lights on), leading some laboratories to perform experiments with animals under a reversed light cycle to overcome this problem. However, it is questionable whether the artificial reversal of the light cycle for short periods guarantees modifications in all the physiological parameters found in normal subjects. The present study evaluated the session 1-session 2 (S1-S2) EPM profile in rats during their normal diurnal or nocturnal phase using different illumination conditions. Prior exposure to the EPM decreased open arm exploration for all groups in S2, regardless of the circadian phase and illumination condition; however, this behavior was decreased in subjects tested during the nocturnal phase, when compared to the diurnal phase. Risk assessment (RA) behavior was decreased under high illumination for both circadian phases in S1 and increased in the first minute of S2, when compared to the last minute of S1. Although open arm exploration and RA behavior were decreased under high illumination, when compared to low illumination conditions in both circadian phases, general locomotor activity was only decreased during the nocturnal phase. The results are discussed in terms of circadian variations in the behavioral profile and as a possible source of variability in pre-clinical models of anxiety.

Circadian rhythm sleep disorders (CRSD)

Circadian Rhythm Sleep Disorders (CRSD) are a group of sleep disorders characterized by a malsynchronization between a person's biological clock and the environmental 24-h schedule. These disorders can lead to harmful psychological and functional difficulties and are often misdiagnosed and incorrectly treated due to the fact that doctors are unaware of their existence. In the following review we describe the characteristics of CRSD, diagnosis, treatment as well as their relationship to psychopathology, psychotropic drugs and head trauma.