Prevalence of Circadian Rhythm Sleep-Wake Disorders and Associated Factors in Euthymic Patients with Bipolar Disorder

Chronobiology of Mood Disorders: The Role of the biological clock in Depression and Bipolar Disorder

Mood disorders, including major depressive disorder (MDD), bipolar disorder (BD), and seasonal affective disorder (SAD), exhibit significant heterogeneity, with disturbances in biological rhythms playing a central role. These disturbances not only contribute to the onset and progression of mood disorders but also serve as important predictors of relapse (Chronos syndrome) and treatment response. Circadian disruptions, influenced by factors such as seasonality, jet lag, shift work, and childbirth, are hallmarks of mood episodes and pivotal in transitions between mood states. Longitudinal studies reveal a bidirectional relationship between circadian dysregulation and mood disorders, suggesting that biological clock abnormalities may both signal and predispose individuals to mood episodes. Despite their significance, no single circadian biomarker has demonstrated sufficient specificity or sensitivity for diagnostic precision. This underscores the urgent need for multimodal approaches that integrate circadian markers with other physiological and behavioral dimensions. Advancing mood disorder care requires biomarkers that capture individualized biological signatures, revealing circadian dysregulation and its interactions with multiple other physiological systems to enable precise subtyping and improved interventions. This review emphasizes the potential of integrating biological rhythms into a dimensional framework, leveraging advanced digital tools and mathematical models to provide ecologically valid insights into mood disorder mechanisms. Such approaches aim to bridge the gap between clinical observations and biological underpinnings, paving the way for biologically informed classifications and personalized treatment strategies. By addressing the complexity of circadian disruptions and their interplay with other systems, this paradigm shift offers a promising path to enhancing mood disorder diagnostics and therapeutics.

Effect of lithium on circadian activity level and flexibility in patients with bipolar disorder: results from the Oxford Lithium Trial

BACKGROUND

Disruption of circadian rest-activity is prevalent in patients with bipolar disorder (BD). Lithium's impact on circadian rhythms has been documented in cell lines, animal models, and pharmacogenomics studies in patients with BD. However, the causal relationship between such disruption and BD remains unclear.

METHODS

We investigated the early effects of lithium on circadian rest-activity in an exploratory analysis of a randomised, placebo-controlled, double-blind six-week study on patients with BD. Participants were assigned to receive either lithium or a placebo in a 1:1 ratio. Circadian activity was monitored using actigraphy, and daily affect was assessed through ecological momentary assessment. A computational model was used to quantify different types of activity variability, and the impact of lithium on activity level, activity onset time and their variability were analysed using linear mixed models.

FINDINGS

Of the thirty-five participants who began treatment, 19 received lithium and 16 received a placebo. Lithium significantly altered circadian rest-activity patterns, including reducing daytime activity levels (after 4 weeks, below as well: Cohen's d = -0.19, p = 0.002, linear mixed model, ibid.), advancing the onset of daytime activity (Cohen's d = -0.14, p = 0.018), and increasing the volatility of both daytime activity level (Cohen's d = 0.10, p = 0.002) and its onset time (Cohen's d = 0.13, p < 0.001), independent of affective symptoms changes.

INTERPRETATION

This study establishes a causal link between lithium treatment and reduced circadian activity with advanced circadian phase, potentially via temporarily increasing their volatility (flexibility). Significant circadian changes were detected within one week of starting lithium, highlighting their potential as an early biomarker for treatment response.

FUNDING

This research was supported by the Wellcome Trust Strategic Award (CONBRIO: Collaborative Oxford Network for Bipolar Research to Improve Outcomes, reference No. 102,616/Z), NIHR Oxford Health Biomedical Research Centre and the NIHR Oxford cognitive health Clinical Research Facility.

Chronotherapeutic Treatments for Psychiatric Disorders: A Narrative Review of Recent Literature

PURPOSE OF THE REVIEW

This narrative review examines the newest findings from clinical trials of chronotherapeutics for psychiatric disorders. We reviewed the potential effects of the most commonly-studied chronotherapeutics such as bright light therapy, dark therapy, melatonin, and chronotherapy on the psychiatric disorders of depression, bipolar disorder, and anxiety disorders.

RECENT FINDINGS

The preponderance of recent clinical trials in chronotherapeutics has focused on bright light therapy in depression. However, there is an emerging body of preliminary studies testing chronotherapeutics in other psychiatric disorders, including bipolar disorder and post-traumatic stress disorder. Chronotherapeutics hold potential to improve sleep in adults with psychiatric conditions as well as psychiatric symptoms. Although the most recent literature demonstrates the promise of these interventions, the current body of work is limited by small sample sizes and relatively few studies outside of depression. Larger-scale trials are needed to refine treatment protocols, develop personalized treatment approaches, and inform dissemination. Studies in psychiatric conditions besides depression are particularly needed.

General procrastination associated with the evening preference in healthy people but not with circadian rhythm sleep-wake disorders with phase delay

Procrastination behavior has been reportedly associated with the evening preference. This study aimed to evaluate its difference between patients with circadian rhythm sleep-wake disorders with phase delay (CRSWDswPD) and healthy controls in terms of evening preference and comorbid psychiatric disorders. Thirty patients with CRSWDswPD and 29 healthy participants were included. In both groups, the general procrastination scale (GPS), Beck Depression Inventory (BDI), and Morningness-Eveningness Questionnaire (MEQ) were administered. Additionally, Adult ADHD Self-Report Scale (ASRS) and autism spectrum quotient (AQ) were also assessed in the patient group. Unexpectedly, GPS was not statistically different between patients with CRSWDswPD and healthy controls. GPS was significantly higher with lower MEQ in the healthy group, whereas the opposite tendency was observed in the patient group. Higher AQ, ASRS, and BDI tended to be associated with higher GPS in the patient group, with the first two being statistically significant. The results suggest that general procrastination is not significantly associated with CRSWDswPD, although it is associated with evening preference in healthy participants. Procrastination in the patient group may be associated with developmental disorders or depression tendencies. Future studies should include simultaneous measurement of circadian markers, other behavioral assessments, a larger population, and untreated patients.

Irregular sleep-wake rhythm disorder: From the pathophysiologic perspective to the treatment

Irregular sleep-wake rhythm disorder (ISWRD) is an intrinsic circadian rhythm disorder caused by loss of the brain's circadian regulation, through changes of the input and/or output to the suprachiasmatic nucleus (SCN), or of the SCN itself. Although there are limited prevalence data for this rare disease, ISWRD is associated with neurodegenerative disorders, including the Alzheimer disease (AD) and the Parkinson disease (PD), which will become increasingly prevalent in an aging population. It additionally presents in childhood developmental disorders, psychiatric disorders, and traumatic brain injury (TBI). Patients present with unpredictable, short sleep periods over a 24-h period, with significant day-to-day and weekly variability. Symptoms manifest as insomnia and excessive daytime sleepiness. Sleep logs and actigraphy monitoring capture rest-activity patterns required for diagnosis. Treatment aims to enhance external circadian cues through timed light therapy, behavioral activity regimens, and melatonin, but efficacy remains quite limited. Pathophysiology of ISWRD in association with various diseases and their specific management are discussed. There is a need for further investigation of disease pathophysiology, development of widely applicable tools for diagnosis, and development of treatments.

How sleep in patients with serious mental illness is recorded and treated, and its impact on service engagement

BACKGROUND

Sleep and mental health share a bidirectional relationship whereby problems in one exacerbate the other. Accordingly, sleep problems are frequent and severe in serious mental illness (SMI) populations, exacerbating SMI symptoms. This study examined the documentation and treatment of sleep problems within anonymised clinical records of SMI patients, and their association with attendance rates and number of appointments scheduled.

METHODS

Patient records between 01.09.2021 and 31.08.2022 were identified and relevant records (n = 229) extracted from an NHS Trust database. Content analysis was used to assess documentation and treatment of sleep problems and Chi-square tests were used to assess demographic differences. Mann-Whitney U tests were used to compare attendance rates and number of appointments scheduled between patients with/without sleep problems.

RESULTS

Most (n = 170; 84 %) patients with sleep problems had no or minimal assessment of the sleep problem within their records. Patients were primarily offered no (n = 115; 57 %) or non-recommended (n = 69; 34 %) sleep treatment. More outpatients were offered no sleep treatment (n = 89; 64 %) than inpatients (n = 26; 41 %) (p = .002) whilst more inpatients were offered non-recommended sleep treatments (n = 33; 52 %) than outpatients (n = 36; 26 %) (p < .001). No significant associations were found between sleep and attendance or appointments scheduled.

CONCLUSIONS

There is a lack of routine clinical attention to sleep assessment and treatment in SMI groups. Where sleep is addressed, treatment often conflicts with guidelines. Improved sleep assessment and treatment could significantly enhance current SMI patient care.

Effects of Sleep Deficiency on Risk, Course, and Treatment of Psychopathology

This article reviews the literature on the relationship between sleep deficiency and unipolar and bipolar depression, anxiety disorders, and posttraumatic stress disorder. We consider the evidence for sleep as a contributory causal factor in the development of psychiatric disorders, as well as sleep as an influential factor related to the outcome and recurrence of psychopathology. A case for sleep deficiency being an important treatment target when sleep and psychiatric disorders are comorbid is also made. Our recommendation is that sleep deficiency is recognized as a means to positively impact the development and course of psychopathology and, as such, is routinely assessed and treated in clinical practice.

Sleep and circadian disruption in bipolar disorders: From psychopathology to digital phenotyping in clinical practice

Sleep and biological rhythms are integral to mood regulation across the lifespan, particularly in bipolar disorder (BD), where alterations in sleep phase, structure, and duration occur in all mood states. These disruptions are linked to poorer quality of life, heightened suicide risk, impaired cognitive function, and increased relapse rates. This review highlights the pathophysiology of sleep disturbances in BD and aims to consolidate understanding and clinical applications of these phenomena. It also summarizes the evolution of sleep and biological rhythms assessment methods, including ecological momentary assessment (EMA) and digital phenotyping. It underscores the importance of recognizing circadian rhythm involvement in mood regulation, suggesting potential therapeutic targets. Future research directions include elucidating circadian clock gene mechanisms, understanding environmental impacts on circadian rhythms, and investigating the bidirectional relationship between sleep disturbances and mood regulation in BD. Standardizing assessment methods and addressing privacy concerns related to EMA technology and digital phenotyping are essential for advancing research. Collaborative efforts are crucial for enhancing clinical applicability and understanding the broader implications of biological rhythms in BD diagnosis and treatment. Overall, recognizing the significance of sleep and biological rhythms in BD offers promise for improved outcomes through targeted interventions and a deeper understanding of the disorder's underlying mechanisms.

Sleep disorders in a naturalistic cohort of Dutch psychiatric outpatients: prevalence rates and associations with psychopathology symptom severity and well-being

Sleep problems are very common in individuals with a mental disorder. Given the abundant evidence indicating the negative impact of disturbed sleep on mental health outcome, insight into the prevalence of all types of sleep disorders in specific mental disorders and neurodevelopmental conditions is of practical importance. Therefore, we estimated the prevalence of six types of sleep disorders with the Holland Sleep Disorders Questionnaire in an overall mental health sample (n = 1082) and separately for different mental and neurodevelopmental conditions. Furthermore, associations between specific sleep disorders, psychopathology and well-being were studied. The impact of the total number of sleep disorders on these associations was examined. Overall, 46.2% of all participants scored above the cut-off for having a sleep disorder. Specifically, 26.8% scored on insomnia, 12.1% on sleep breathing disorders, 9.7% on hypersomnia, 13.7% on circadian rhythm sleep-wake disorders, 11.2% on parasomnia, and 17.9% on sleep-related movement disorders. Most sleep disorders were associated with greater severity of psychopathology and lower well-being. These associations got stronger with an increasing number of sleep disorders. Our study revealed higher suspected prevalence of most sleep disorders in a mental disorder sample compared to the general population. Moreover, the presence of sleep disorder(s) was strongly associated with symptom severity and reduced well-being. These findings extend the notion that early detection and treatment of sleep disorders in mental health populations is essential for psychiatric outcome.

The sleep-circadian interface: A window into mental disorders

Sleep, circadian rhythms, and mental health are reciprocally interlinked. Disruption to the quality, continuity, and timing of sleep can precipitate or exacerbate psychiatric symptoms in susceptible individuals, while treatments that target sleep-circadian disturbances can alleviate psychopathology. Conversely, psychiatric symptoms can reciprocally exacerbate poor sleep and disrupt clock-controlled processes. Despite progress in elucidating underlying mechanisms, a cohesive approach that integrates the dynamic interactions between psychiatric disorder with both sleep and circadian processes is lacking. This review synthesizes recent evidence for sleep-circadian dysfunction as a transdiagnostic contributor to a range of psychiatric disorders, with an emphasis on biological mechanisms. We highlight observations from adolescent and young adults, who are at greatest risk of developing mental disorders, and for whom early detection and intervention promise the greatest benefit. In particular, we aim to a) integrate sleep and circadian factors implicated in the pathophysiology and treatment of mood, anxiety, and psychosis spectrum disorders, with a transdiagnostic perspective; b) highlight the need to reframe existing knowledge and adopt an integrated approach which recognizes the interaction between sleep and circadian factors; and c) identify important gaps and opportunities for further research.

The engagement of autophagy in maniac disease

AIMS

Mania is a prevalent psychiatric disorder with undefined pathological mechanism. Here, we reviewed current knowledge indicating the potential involvement of autophagy dysregulation in mania and further discussed whether targeting autophagy could be a promising strategy for mania therapy.

DISCUSSIONS

Accumulating evidence indicated the involvement of autophagy in the pathology of mania. One of the most well-accepted mechanisms underlying mania, circadian dysregulation, showed mutual interaction with autophagy dysfunction. In addition, several first-line drugs for mania therapy were found to regulate neuronal autophagy. Besides, deficiencies in mitochondrial quality control, neurotransmission, and ion channel, which showed causal links to mania, were intimately associated with autophagy dysfunction.

CONCLUSIONS

Although more efforts should be made to either identify the key pathology of mania, the current evidence supported that autophagy dysregulation may act as a possible mechanism involved in the onset of mania-like symptoms. It is therefore a potential strategy to treat manic disorder by correting autophagy.

The concept of "metabolic jet lag" in the pathophysiology of bipolar disorder: implications for research and clinical care

Bipolar disorder (BD) is a potentially chronic mental disorder marked by recurrent depressive and manic episodes, circadian rhythm disruption, and changes in energetic metabolism. "Metabolic jet lag" refers to a state of shift in circadian patterns of energy homeostasis, affecting neuroendocrine, immune, and adipose tissue function, expressed through behavioral changes such as irregularities in sleep and appetite. Risk factors include genetic variation, mitochondrial dysfunction, lifestyle factors, poor gut microbiome health and abnormalities in hunger, satiety, and hedonistic function. Evidence suggests metabolic jet lag is a core component of BD pathophysiology, as individuals with BD frequently exhibit irregular eating rhythms and circadian desynchronization of their energetic metabolism, which is associated with unfavorable clinical outcomes. Although current diagnostic criteria lack any assessment of eating rhythms, technological advancements including mobile phone applications and ecological momentary assessment allow for the reliable tracking of biological rhythms. Overall, methodological refinement of metabolic jet lag assessment will increase knowledge in this field and stimulate the development of interventions targeting metabolic rhythms, such as time-restricted eating.

Effects of exogenous melatonin on sleep and circadian rhythm parameters in bipolar disorder with comorbid delayed sleep-wake phase disorder: An actigraphic study

The present study evaluates the effect of exogenous melatonin (exo-MEL) on sleep and circadian parameters in patients with bipolar disorder (BD) and delayed sleep-wake phase disorder (DSWPD). BD euthymic patients (n = 83, mean age = 45.13 ± 13.68, males 56%) were evaluated for chronotype (reduced Morningness-Eveningness Questionnaire [rMEQ]), sleep quality (Pittsburgh Sleep Quality Index), sleep and circadian parameters (actigraphic monitoring). Patients that fulfilled criteria for DSWPD (n = 25) were treated for three months with exo-MEL 2 mg administered approximately 4 h before the sleep onset time (SOT) actigraphically-determined at baseline. Sleep and circadian parameters at baseline (T0) and after the exo-MEL treatment (T1) were compared using paired Wilcoxon test. In patients that completed the treatment (n = 19), the rMEQ score increased between T0 (median = 8.0 [IQR = 7.0, 11.0]) and T1 (median = 13.5 [IQR = 9.3, 15.0], p-value = 0.006), the SOT was advanced between T0 (median = 00:55 [IQR = 00:25, 01:39] and T1 (median = 00:09 [IQR = 23:41, 01:04], p-value = 0.039), the sleep efficiency and total sleep time increased (T0: median = 84.4 [IQR = 81.3, 89.4]; T1 (median = 90.3 [IQR = 85.5, 92.9] %, p-value = 0.01, and T0: median = 7.20 [IQR = 6.15, 8.15]; T1: median = 7.7 [IQR = 7.0, 9.3] hours, p-value = 0.04, respectively). These results indicate that in BD with comorbid DSWPD, the self-reported chronotype, the sleep onset time, and sleep efficiency and duration were modified after a personalized treatment with exo-MEL, suggesting its potential efficacy in improving sleep patterns in BD. The absence of proper control groups and of treatment randomization constitute limitations of our study and further randomized controlled trials are required to confirm our results.

Sleep problems and referral intentions in mental health services: service user self-report and staff proxy report surveys

BACKGROUND

Sleep problems are common in mental health service users, but few non-pharmacological therapies are offered. Therapies are being developed and tested, but there may be barriers to these therapies reaching those who need them.

METHODS

Light-Dark and Activity Rhythm Therapy (L-DART), is a new sleep therapy delivered by an occupational therapist, which has been feasibility tested in people with schizophrenia spectrum diagnoses. This paper presents two surveys, conducted with mental health staff and service users, on sleep problems, treatment wishes; and barriers and facilitators to uptake of L-DART or similar therapies. Descriptive statistics, single-level and multi-level ordinal logistic regression were used to examine factors associated with sleep problems and referral intentions.

FINDINGS

Sleep problems were commonly identified by staff and service users, there was demand for non-pharmacological intervention across diagnostic and demographic categories, but staff readiness to refer differed according to NHS Trust and service user diagnosis. Staff and service user reports differed in awareness of sleep disordered breathing and parasomnias, and wish for referral. Staff were more confident identifying sleep problems than addressing them, but more training was associated with greater confidence concerning both assessment and treatment.

CONCLUSIONS

A range of sleep problems are prevalent and recognised in mental health service users, and there is an unmet need for non-pharmacological sleep interventions. Improving suitable resources to support self-management in this group may help; Staff and service users also reported a high readiness to refer or be referred for sleep interventions. Staff training to improve identification of sleep problems, and differentiation between types of sleep problems, would support access to the most appropriate treatments.

Delayed sleep-wake phase disorder and its related sleep behaviors in the young generation

Delayed sleep-wake phase disorder (DSWPD) is a sleep disorder in which the habitual sleep-wake timing is delayed, resulting in difficulty in falling asleep and waking up at the desired time. Patients with DSWPD frequently experience fatigue, impaired concentration, sleep deprivation during weekdays, and problems of absenteeism, which may be further complicated by depressive symptoms. DSWPD is typically prevalent during adolescence and young adulthood. Although there are no studies comparing internationally, the prevalence of DSWPD is estimated to be approximately 3% with little racial differences between Caucasians and Asians. The presence of this disorder is associated with various physiological, genetic and psychological as well as behavioral factors. Furthermore, social factors are also involved in the mechanism of DSWPD. Recently, delayed sleep phase and prolonged sleep duration in the young generation have been reported during the period of COVID-19 pandemic-related behavioral restrictions. This phenomenon raises a concern about the risk of a mismatch between their sleep-wake phase and social life that may lead to the development of DSWPD after the removal of these restrictions. Although the typical feature of DSWPD is a delay in circadian rhythms, individuals with DSWPD without having misalignment of objectively measured circadian rhythm markers account for approximately 40% of the cases, wherein the psychological and behavioral characteristics of young people, such as truancy and academic or social troubles, are largely involved in the mechanism of this disorder. Recent studies have shown that DSWPD is frequently comorbid with psychiatric disorders, particularly mood and neurodevelopmental disorders, both of which have a bidirectional association with the pathophysiology of DSWPD. Additionally, patients with DSWPD have a strong tendency toward neuroticism and anxiety, which may result in the aggravation of insomnia symptoms. Therefore, future studies should address the effectiveness of cognitive-behavioral approaches in addition to chronobiological approaches in the treatment of DSWPD.

Effects of Sleep Deficiency on Risk, Course, and Treatment of Psychopathology

This article reviews the literature on the relationship between sleep deficiency and unipolar and bipolar depression, anxiety disorders, and posttraumatic stress disorder. We consider the evidence for sleep as a contributory causal factor in the development of psychiatric disorders, as well as sleep as an influential factor related to the outcome and recurrence of psychopathology. A case for sleep deficiency being an important treatment target when sleep and psychiatric disorders are comorbid is also made. Our recommendation is that sleep deficiency is recognized as a means to positively impact the development and course of psychopathology and, as such, is routinely assessed and treated in clinical practice.

Neurobiological and behavioral mechanisms of circadian rhythm disruption in bipolar disorder: A critical multi-disciplinary literature review and agenda for future research from the ISBD task force on chronobiology

AIM

Symptoms of bipolar disorder (BD) include changes in mood, activity, energy, sleep, and appetite. Since many of these processes are regulated by circadian function, circadian rhythm disturbance has been examined as a biological feature underlying BD. The International Society for Bipolar Disorders Chronobiology Task Force (CTF) was commissioned to review evidence for neurobiological and behavioral mechanisms pertinent to BD.

METHOD

Drawing upon expertise in animal models, biomarkers, physiology, and behavior, CTF analyzed the relevant cross-disciplinary literature to precisely frame the discussion around circadian rhythm disruption in BD, highlight key findings, and for the first time integrate findings across levels of analysis to develop an internally consistent, coherent theoretical framework.

RESULTS

Evidence from multiple sources implicates the circadian system in mood regulation, with corresponding associations with BD diagnoses and mood-related traits reported across genetic, cellular, physiological, and behavioral domains. However, circadian disruption does not appear to be specific to BD and is present across a variety of high-risk, prodromal, and syndromic psychiatric disorders. Substantial variability and ambiguity among the definitions, concepts and assumptions underlying the research have limited replication and the emergence of consensus findings.

CONCLUSIONS

Future research in circadian rhythms and its role in BD is warranted. Well-powered studies that carefully define associations between BD-related and chronobiologically-related constructs, and integrate across levels of analysis will be most illuminating.

Chronbiologically-based sub-groups in bipolar I disorder: A latent profile analysis

BACKGROUND

Bipolar disorder presents with significant phenotypic heterogeneity. The aim of this study was to investigate whether bipolar disorder, type I (BDI) subjects could be meaningfully classified into homogeneous groups according to activity, sleep, and circadian characteristics using latent profile analysis (LPA). We hypothesized that distinct BDI sub-groups would be identified based primarily on circadian-associated markers.

MATERIALS AND METHODS

105 individuals with BDI were included in the study. Seventeen activity, sleep, and circadian characteristics were assessed via actigraphy and clinical assessments. LPA was conducted to stratify our sample into homogenous sub-groups. Differences between groups on demographic, clinical, activity, sleep, and circadian characteristics were explored.

RESULTS

Two distinct groups were identified, a High Chronobiological Disturbance group (HCD) (56%, N = 59) and a Low Chronobiological Disturbance group (LCD) (41%; N = 46). Circadian variables were the defining characteristics in sub-group determination. Large effect sizes and magnitudes of association were noted in circadian variables between HCD and LCD sub-groups. Several circadian rhythm variables accounted for a large percentage of the variance between HCD and LCD sub-groups. No differences were noted between sub-groups on demographic characteristics and the psychiatric medications currently in use. Mood state did not significantly impact sub-group differences.

LIMITATIONS

The protocol was cross-sectional in design. Longitudinal studies are required to determine the stability of the identified sub-groups.

CONCLUSION

LPA was able to identify sub-groups in BDI with circadian variables being the most distinguishing factors in determining sub-group class membership. Future research should explore the role that circadian characteristics can play in defining sub-phenotypes of bipolar disorder.

The relationship between physical activity, BMI, circadian rhythm, and sleep with cognition in bipolar disorder

BACKGROUND

Cognitive deficits affect a significant proportion of patients with bipolar disorder (BD). Problems with sustained attention have been found independent of mood state and the causes are unclear. We aimed to investigate whether physical parameters such as activity levels, sleep, and body mass index (BMI) may be contributing factors.

METHODS

Forty-six patients with BD and 42 controls completed a battery of neuropsychological tests and wore a triaxial accelerometer for 21 days which collected information on physical activity, sleep, and circadian rhythm. Ex-Gaussian analyses were used to characterise reaction time distributions. We used hierarchical regression analyses to examine whether physical activity, BMI, circadian rhythm, and sleep predicted variance in the performance of cognitive tasks.

RESULTS

Neither physical activity, BMI, nor circadian rhythm predicted significant variance on any of the cognitive tasks. However, the presence of a sleep abnormality significantly predicted a higher intra-individual variability of the reaction time distributions on the Attention Network Task.

CONCLUSIONS

This study suggests that there is an association between sleep abnormalities and cognition in BD, with little or no relationship with physical activity, BMI, and circadian rhythm.

The relationship between sleep and depression and bipolar disorder in children and young people

BACKGROUND

Sleep difficulties are often reported in practice, and are part of the diagnostic criteria for depression and bipolar disorder.

AIMS

To inform the understanding of the relationship between sleep and both depression and bipolar disorder.

METHOD

We conducted a narrative literature review of affective disorders and sleep difficulties in children and young people.

RESULTS

Specific sleep disorders, such as parasomnias, narcolepsy and sleep-related movement disorders, are associated with depression, whereas insomnia, obstructive sleep apnoea and circadian rhythm disorders are associated with both depression and bipolar disorder in children and young people. Conversely, children and young people with depression can present with a number of sleep difficulties, and these are associated with higher depression severity and greater fatigue, suicidal ideation, physical complaints, pain and decreased concentration. Sleep disturbances among adolescents with bipolar disorder can affect the severity of depressive and manic symptoms, are a poor prognostic indicator and have been associated with social and academic impairment. Antidepressants and antipsychotics can directly affect sleep architecture, which clinicians need to be aware of. Non-pharmacological interventions for sleep problems could prevent and/or minimise the risk of relapse in affective disorders.

CONCLUSIONS

Sleep difficulties can occur before, during and after an episode of depression or bipolar disorder, and have a higher prevalence in affective disorders compared with the general population. A multi-modal approach would include the treatment of both the affective and specific sleep disorder. Further research is needed in this field to understand the impact of combined interventions on clinical outcomes.

Altered distribution of resting periods of daily locomotor activity in patients with delayed sleep phase disorder

Delayed sleep phase disorder (DSPD) and mood disorders have a close relationship. However, the shared mechanisms by DSPD and mood disorders have not been well-elucidated. We previously found that micro-fluctuations in human behaviors are organized by robust statistical laws (behavioral organization), where the cumulative distributions of resting and active period durations take a power-law distribution form and a stretched exponential functional form, respectively. Further, we found that the scaling exponents of resting period distributions significantly decreased in major depressive disorder (MDD). In this study, we hypothesized that DSPD had similar characteristics of the altered behavioral organization to that of MDD. Locomotor activity data were acquired for more than 1 week from 17 patients with DSPD and 17 age- and gender-matched healthy participants using actigraphy. We analyzed the cumulative distributions of resting and active period durations in locomotor activity data and subsequently derived fitting parameters of those distributions. Similar to patients with MDD, we found that resting period distributions took a power-law form over the range of 2-100 min, with significantly lower values of scaling exponents γ in patients with DSPD compared with healthy participants. The shared alteration in γ suggests the existence of similar pathophysiology between DSPD and MDD.

A Predictive Model of Risk Factors for Conversion From Major Depressive Disorder to Bipolar Disorder Based on Clinical Characteristics and Circadian Rhythm Gene Polymorphisms

BACKGROUND

Bipolar disorder (BD) is easy to be misdiagnosed as major depressive disorder (MDD), which may contribute to a delay in treatment and affect prognosis. Circadian rhythm dysfunction is significantly associated with conversion from MDD to BD. So far, there has been no study that has revealed a relationship between circadian rhythm gene polymorphism and MDD-to-BD conversion. Furthermore, the prediction of MDD-to-BD conversion has not been made by integrating multidimensional data. The study combined clinical and genetic factors to establish a predictive model through machine learning (ML) for MDD-to-BD conversion.

METHOD

By following up for 5 years, 70 patients with MDD and 68 patients with BD were included in this study at last. Single nucleotide polymorphisms (SNPs) of the circadian rhythm genes were selected for detection. The R software was used to operate feature screening and establish a predictive model. The predictive model was established by logistic regression, which was performed by four evaluation methods.

RESULTS

It was found that age of onset was a risk factor for MDD-to-BD conversion. The younger the age of onset, the higher the risk of BD. Furthermore, suicide attempts and the number of hospitalizations were associated with MDD-to-BD conversion. Eleven circadian rhythm gene polymorphisms were associated with MDD-to-BD conversion by feature screening. These factors were used to establish two models, and 4 evaluation methods proved that the model with clinical characteristics and SNPs had the better predictive ability.

CONCLUSION

The risk factors for MDD-to-BD conversion have been found, and a predictive model has been established, with a specific guiding significance for clinical diagnosis.

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.

Circadian Rhythms in Mood Disorders

Altered behavioral rhythms are a fundamental diagnostic feature of mood disorders. Patients report worse subjective sleep and objective measures confirm this, implicating a role for circadian rhythm disruptions in mood disorder pathophysiology. Molecular clock gene mutations are associated with increased risk of mood disorder diagnosis and/or severity of symptoms, and mouse models of clock gene mutations have abnormal mood-related behaviors. The mechanism by which circadian rhythms contribute to mood disorders remains unknown, however, circadian rhythms regulate and are regulated by various biological systems that are abnormal in mood disorders and this interaction is theorized to be a key component of mood disorder pathophysiology. A growing body of evidence has begun defining how the interaction of circadian and neurotransmitter systems influences mood and behavior, including the role of current antidepressants and mood stabilizers. Additionally, the hypothalamus-pituitary-adrenal (HPA) axis interacts with both circadian and monoaminergic systems and may facilitate the contribution of environmental stressors to mood disorder pathophysiology. The central role of circadian rhythms in mood disorders has led to the development of chronotherapeutics, which are treatments designed specifically to target circadian rhythm regulators, such as sleep, light, and melatonin, to produce an antidepressant response.

Association between circadian activity rhythms and mood episode relapse in bipolar disorder: a 12-month prospective cohort study

A significant proportion of patients with bipolar disorder experience mood episode relapses. We examined whether circadian activity rhythms were associated with mood episode relapses in patients with bipolar disorder. This prospective cohort study included outpatients with bipolar disorder who participated in a study titled "Association between the Pathology of Bipolar Disorder and Light Exposure in Daily Life (APPLE) cohort study." The participants' physical activity was objectively assessed using a wrist-worn accelerometer over 7 consecutive days for the baseline assessment and then at the 12-month follow-up for mood episode relapses. The levels and timing of the circadian activity rhythms were estimated using a cosinor analysis and a nonparametric circadian rhythm analysis. Of the 189 participants, 88 (46%) experienced mood episodes during follow-up. The Cox proportional hazards model adjusting for potential confounders showed that a robust circadian activity rhythm, including midline-estimating statistic of rhythm (MESOR) and amplitude by cosinor analysis and 10 consecutive hours with the highest amplitude values (M10) by the nonparametric circadian rhythm analysis, was significantly associated with a decrease in mood episode relapses (per counts/min, hazard ratio [95% confidence interval]: MESOR, 0.993 [0.988-0.997]; amplitude, 0.994 [0.988-0.999]; and M10, 0.996 [0.993-0.999]). A later timing of the circadian activity rhythm (M10 onset time) was significantly associated with an increase in the depressive episode relapses (per hour; 1.109 [1.001-1.215]). We observed significant associations between circadian activity rhythms and mood episode relapses in bipolar disorder.

Sleep disorders in attention-deficit hyperactivity disorder and autism spectrum disorder: a pragmatic approach to assessment and management

Sleep is essential for survival and humans spend approximately one-third of their life asleep. Adequate sleep is needed to maintain both physical and psychological health. Routinely getting less than the recommended amount of sleep for your age can have profound negative effects on health, such as increasing the likeliness of psychiatric illness, diabetes, cardiovascular disease and stroke. In children and adults with neurodevelopmental disorders, the prevalence of sleep disorders is significantly higher than in the general population. Given the relationship between sleep and psychiatric disorders, it is essential that psychiatrists have knowledge of the principles of sleep medicine. In this article, we focus on the common sleep disorders found in those with attention-deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) and give an overview of screening, diagnosis and management.

Effect of lithium on circadian rhythm in bipolar disorder: A systematic review and meta-analysis

OBJECTIVES

Circadian rhythm disruption is commonly reported in patients with bipolar disorder. Lithium has been suggested to have effects on the circadian clock, the biological basis of the circadian rhythm. The objective of the current review was to review systematically the existing studies on the effect of lithium on circadian rhythm in patients with bipolar disorder.

METHODS

We systematically searched the scientific literature up to September 2020 for experimental or observational studies which measured circadian rhythm in bipolar patients taking lithium (in comparison with placebo or other active treatments) and carried out a meta-analysis. Circadian rest-activity was our primary outcome, but we also collected data about sleep quality and chronotype (Morningness-Eveningness). The protocol was registered in PROSPERO (CRD42018109790).

RESULTS

Four observational studies (n = 668) and one experimental study (n = 29) were included. Results from the meta-analysis suggest a potential association between lithium and shifts towards morningness (standardized mean difference [SMD]: 0.42, 95% confidence interval [CI]: -0.05 to 0.90). One cohort study with 21 days of follow-up found that patients treated with lithium had significantly larger amplitude (0.68, 0.01 to 1.36) when compared to anticonvulsants.

CONCLUSION

This review highlights the insufficient evidence to inform us about the effect of lithium on circadian rhythm. However, we found that chronotype can be a potential target for further exploration of biomarkers or biosignatures of lithium treatment in patients with bipolar disorder. Further studies with prospective and longitudinal study design, adopting actigraphy to monitor daily circadian rest-activity changes are needed.

Prevalence of Circadian Rhythm Sleep-Wake Disorder in Outpatients with Schizophrenia and Its Association with Psychopathological Characteristics and Psychosocial Functioning

The prevalence of circadian rhythm sleep-wake disorder (CRSWD) among patients with schizophrenia is not clear. The effect of comorbid CRSWD on such patients has also not been fully evaluated yet. Outpatients with schizophrenia in the maintenance phase who visited Tokyo Women’s Medical University Hospital between April 2018 and March 2019 participated in this study. The Brief Psychiatric Rating Scale (BPRS), the Clinical Global Impressions–Severity Illness Scale (CGI-S), Global Assessment of Functioning (GAF), World Health Organization Disability Assessment Schedule II, Insomnia Severity Index (ISI), and Morningness–Eveningness Questionnaire (MEQ) were administered, and the patient responses with and without CRSWD were compared. Of the 105 patients with schizophrenia, 19 (18.1%) had CRSWD. There were trends toward higher BPRS and lower GAF scores in the CRSWD group than in the non-CRSWD group, although these did not reach statistical significance following a false discovery rate correction. Among the BPRS subitems, the anxiety scores were significantly higher in the CRSWD group than in the non-CRSWD group (p < 0.01). CRSWD was highly prevalent among patients with schizophrenia in the maintenance phase. Comorbidities of CRSWD may affect psychopathological characteristics and psychosocial functioning.

Circadian depression: A mood disorder phenotype

Major mood syndromes are among the most common and disabling mental disorders. However, a lack of clear delineation of their underlying pathophysiological mechanisms is a major barrier to prevention and optimised treatments. Dysfunction of the 24-h circadian system is a candidate mechanism that has genetic, behavioural, and neurobiological links to mood syndromes. Here, we outline evidence for a new clinical phenotype, which we have called 'circadian depression'. We propose that key clinical characteristics of circadian depression include disrupted 24-h sleep-wake cycles, reduced motor activity, low subjective energy, and weight gain. The illness course includes early age-of-onset, phenomena suggestive of bipolarity (defined by bidirectional associations between objective motor and subjective energy/mood states), poor response to conventional antidepressant medications, and concurrent cardiometabolic and inflammatory disturbances. Identifying this phenotype could be clinically valuable, as circadian-targeted strategies show promise for reducing depressive symptoms and stabilising illness course. Further investigation of underlying circadian disturbances in mood syndromes is needed to evaluate the clinical utility of this phenotype and guide the optimal use of circadian-targeted interventions.

Sleep and Sex: A Review of the Interrelationship of Sleep and Sexuality Disorders in the Female Population, Through the Lens of Sleeping Beauty Syndrome

INTRODUCTION

For many, sleep and sex are crucial for physical, emotional, and mental well-being. Poor sleep quality is linked to a myriad of ailments from coronary artery disease to major depressive disorder. Likewise, a decrease in the frequency of sexual activity is associated with a decrease in self-rated health status. Kleine-Levin syndrome (KLS) is a rare sleep disorder that provides a unique lens to examine the intricate interplay between sleep and sex as it is one of the few sleep disorders defined by concomitant sexual dysfunction.

OBJECTIVES

This study reviews the literature on links between sleep disorders and sexuality with a focus on women's health followed by a case study of unusual patient with KLS with persistent genital arousal disorder.

METHODS

Literature searches were conducted for English language publications, including foreign language publications with English abstracts with ninety-five articles reviewed. The literature review is followed by a case report.

RESULTS

We review the known literature linking sleep and women's sexual health with a focus on insomnia, circadian rhythm sleep disorder, obstructive sleep apnea, restless leg syndrome, sexsomnia, and KLS. We then present a case of KLS-associated persistent genital arousal disorder, which was amenable to treatment with a multimodal approach aimed at symptomatic relief with intravaginal diazepam suppositories, topical clitoral lidocaine, and duloxetine.

CONCLUSION

This case highlights that hypersexuality and persistent arousal cannot effectively be treated in isolation but rather must be contextualized within a patient's broader medical history and diagnoses. Specifically, sleep quality and potential sleep disorders should be assessed for those presenting with sexual health complaints (and vice versa). Zwerling B, Keymeulen S, Krychman ML. Sleep and Sex: A Review of the Interrelationship of Sleep and Sexuality Disorders in the Female Population, Through the Lens of Sleeping Beauty Syndrome. Sex Med Rev 2021;9:221-229.

Evening chronotype, disordered eating behavior, and poor dietary habits in bipolar disorder

OBJECTIVE

Our aim was to evaluate the relationship between evening chronotype, a proxy marker of circadian system dysfunction, and disordered eating behavior and poor dietary habits in individuals with bipolar disorder (BD).

METHODS

In this cross-sectional study, we evaluated 783 adults with BD. Chronotype was determined using item 5 from the reduced Morningness-Eveningness Questionnaire. The Eating Disorder Diagnostic Scale (EDDS) and the Rapid Eating Assessment for Participants-Shortened Version (REAP-S) were used to assess disordered eating behavior and dietary habits respectively. General linear models and logistic regression models were utilized to evaluate differences between chronotype groups.

RESULTS

Two hundred and eight (27%) BD participants self-identified as having evening chronotypes. Compared to non-evening types, evening types were younger (P < 0.01) and, after controlling for age, had higher mean EDDS composite z-scores (P < 0.01); higher rates of binge-eating (BE) behavior (P = 0.04), bulimia nervosa (P < 0.01), and nocturnal eating binges (P < 0.01); and a higher body mass index (P = 0.04). Compared to non-evening types, evening chronotypes had a lower REAP-S overall score (P < 0.01) and scored lower on the 'healthy foods' and 'avoidance of unhealthy food' factors. Evening types also skipped breakfast more often (P < 0.01), ate less fruit (P = 0.02) and vegetables (P = 0.04), and consumed more fried foods (P < 0.01), unhealthy snacks (P = 0.02), and soft drinks (P = 0.01).

CONCLUSIONS

Our findings suggest that the circadian system plays a role in the disordered eating and unhealthy dietary behaviors observed in BD patients. The circadian system may therefore represent a therapeutic target in BD-associated morbidity that warrants further investigation.

Using Chronobiological Phenotypes to Address Heterogeneity in Bipolar Disorder

Bipolar disorder (BD) is a neuropsychiatric mood disorder characterized by recurrent episodes of mania and depression in addition to disruptions in sleep, energy, appetite, and cognitive functions-rhythmic behaviors that typically change on daily cycles. BD symptoms can also be provoked by seasonal changes, sleep, and/or circadian disruption, indicating that chronobiological factors linked to the circadian clock may be a common feature in the disorder. Research indicates that BD exists on a clinical spectrum, with distinct subtypes often intersecting with other psychiatric disorders. This heterogeneity has been a major challenge to BD research and contributes to problems in diagnostic stability and treatment outcomes. To address this heterogeneity, we propose that chronobiologically related biomarkers could be useful in classifying BD into objectively measurable phenotypes to establish better diagnoses, inform treatments, and perhaps lead to better clinical outcomes. Presently, we review the biological basis of circadian time keeping in humans, discuss the links of BD to the circadian clock, and pre-sent recent studies that evaluated chronobiological measures as a basis for establishing BD phenotypes. We conclude that chronobiology may inform future research using other novel techniques such as genomics, cell biology, and advanced behavioral analyses to establish new and more biologically based BD phenotypes.

Sleep and Circadian Rhythm Disorder in Bipolar Affective Disorder

Symptoms of affective disorders encompass a range of changes to biological processes such as sleep and appetite. These processes are regulated over a 24-h cycle known as the circadian rhythm. Sleep is a particularly useful marker of this rhythm as it is readily measurable and functionally significant. Sleep disturbance is common in bipolar affective disorder and may act as a marker, and precipitant, of relapse. Circadian rhythms are modulated by environmental and social cues and have been shown to be influenced by treatment in BPAD. As such understanding of circadian rhythms may lead to a better understanding of the pathophysiology of BPAD and its treatment. This chapter will explore the neurobiology of the circadian clock and the putative role of circadian rhythm dysregulation in the pathophysiology and treatment of bipolar affective disorder (BPAD).

The use of melatonin in adult psychiatric disorders: Expert recommendations by the French institute of medical research on sleep (SFRMS)

Melatonin is a hormone secreted by the pineal gland at night. This hormone has many physiological functions, the main one being to synchronise individuals' biological rhythms. Exogenous melatonin has the same chronobiotic action, even at small doses (0.125mg). In addition, a sleep-inducing (soporific) action appears to occur in a dose-effect relationship, i.e. as the dose increases. In psychiatric disorders, these two effects could have interesting applications in clinical practice. The French institute of medical research on sleep (SFRMS) appointed a group of experts to conduct a consensus conference to study the indications of melatonin and the conditions of its prescription. An account of the conclusions on adult psychiatric disorders (presented orally at the Congress on Sleep in Marseille, 23 November 2017) is given here. Exogenous melatonin proves to be useful among patients with a stabilized psychiatric disorder or in remission, to prevent relapse in case of associated complaints of insomnia, poor quality sleep or delayed sleep phase syndrome. During acute phases, melatonin could be used as an adjuvant treatment when there are insomnia symptoms, in mood disorders (bipolar disorder, major depressive disorder, seasonal affective disorder), in attention deficit hyperactivity disorder (ADHD), in peri-surgical anxiety and in schizophrenia. In somatoform disorders, melatonin is a possible treatment for painful symptoms in fibromyalgia, irritable bowel syndrome, functional dyspeptic syndrome and temporomandibular joint dysfunction.

Significant role of gene-gene interactions of clock genes in mood disorder

BACKGROUND

The genetic interactions in the circadian rhythm biological system are promising as a source of pathophysiology in mood disorder. We examined the role of the gene-gene interactions of clock genes in mood disorder.

METHODS

We included 413 patients with mood disorder and 1294 controls. The clock genes investigated were BHLHB2, CLOCK, CSNK1E, NR1D1, PER2, PER3, and TIMELESS. Allele, genotype, and haplotype associations were tested. Gene--gene interactions were analyzed using the non-parametric model-free multifactor-dimensionality reduction (MDR) method.

RESULTS

TIMELESS rs4630333 and CSNK1E rs135745 were significantly associated with both major depressive disorder and bipolar disorder. The CLOCK haplotype was also strongly associated. The genetic roles of these SNPs were consistent from the allele and genotypic associations to the MDR interaction results. In MDR analysis, the combination of TIMELESS rs4630333 and CSNK1E rs135745 exhibited the most significant association with mood disorders in the two-locus model. BHLHB2 rs2137947 for major depressive disorder and CLOCK rs12649507 for bipolar disorder were the most significant third loci in the three-locus combination model. The four-locus SNP combination model showed the best balanced accuracy (BA), but its cross-validation consistency (CVC) was unsatisfactory.

LIMITATIONS

We included only 17 SNPs for seven circadian genes due to our limited resources; all subjects were ethnically Korean.

CONCLUSIONS

Our results suggest significant single-gene associations and gene-gene interactions of circadian genes with mood disorder. Gene-gene interactions play a crucial role in mood disorder, even when individual clock genes do not have significant roles.

Traits related to bipolar disorder are associated with an increased post-illumination pupil response

Mood states in bipolar disorder appear to be closely linked to changes in sleep and circadian function. It has been suggested that hypersensitivity of the circadian system to light may be a trait vulnerability for bipolar disorder. Healthy persons with emotional-behavioural traits associated with bipolar disorder also appear to exhibit problems with circadian rhythms, which may be associated with individual differences in light sensitivity. This study investigated the melanopsin-driven post-illumination pupil response (PIPR) in relation to emotional-behavioural traits associated with bipolar disorder (measured with the General Behavior Inventory) in a non-clinical group (n = 61). An increased PIPR was associated with increased bipolar disorder-related traits. Specifically, the hypomania scale of the General Behavior Inventory was associated with an increased post-blue PIPR. Further, both the full hypomania and shortened '7 Up' scales were significantly predicted by PIPR, after age, sex and depressive traits were controlled. These findings suggest that increased sensitivity to light may be a risk factor for mood problems in the general population, and support the idea that hypersensitivity to light is a trait vulnerability for, rather than symptom of, bipolar disorder.

Sleep Disturbance in Bipolar Disorder: Neuroglia and Circadian Rhythms

The worldwide prevalence of sleep disorders is approximately 50%, with an even higher occurrence in a psychiatric population. Bipolar disorder (BD) is a severe mental illness characterized by shifts in mood and activity. The BD syndrome also involves heterogeneous symptomatology, including cognitive dysfunctions and impairments of the autonomic nervous system. Sleep abnormalities are frequently associated with BD and are often a good predictor of a mood swing. Preservation of stable sleep-wake cycles is therefore a key to the maintenance of stability in BD, indicating the crucial role of circadian rhythms in this syndrome. The symptom most widespread in BD is insomnia, followed by excessive daytime sleepiness, nightmares, difficulty falling asleep or maintaining sleep, poor sleep quality, sleep talking, sleep walking, and obstructive sleep apnea. Alterations in the structure or duration of sleep are reported in all phases of BD. Understanding the role of neuroglia in BD and in various aspects of sleep is in nascent state. Contributions of the different types of glial cells to BD and sleep abnormalities are discussed in this paper.

Circadian rhythm in bipolar disorder: A review of the literature

Sleep disturbances and circadian rhythm dysfunction have been widely demonstrated in patients with bipolar disorder (BD). Irregularity of the sleep-wake rhythm, eveningness chronotype, abnormality of melatonin secretion, vulnerability of clock genes, and the irregularity of social time cues have also been well-documented in BD. Circadian rhythm dysfunction is prominent in BD compared with that in major depressive disorders, implying that circadian rhythm dysfunction is a trait marker of BD. In the clinical course of BD, the circadian rhythm dysfunctions may act as predictors for the first onset of BD and the relapse of mood episodes. Treatments focusing on sleep disturbances and circadian rhythm dysfunction in combination with pharmacological, psychosocial, and chronobiological treatments are believed to be useful for relapse prevention. Further studies are therefore warranted to clarify the relation between circadian rhythm dysfunction and the pathophysiology of BD to develop treatment strategies for achieving recovery in BD patients.

The role of affective temperaments assessed by the Temperament Evaluation of Memphis, Pisa and San Diego-Autoquestionnaire (TEMPS-A) in the relationship between morningness-eveningness and bipolarity

BACKGROUND

Growing number of studies indicates a link between eveningness chronotype, affective temperaments and bipolarity, both in patients with mood disorders and in general population. Given these tripartite associations, we hypothesized that the effect of circadian preferences on the bipolarity may be mediated by the temperamental traits.

METHODS

The study included 1449 subjects (402 men and 1047 women). They all fulfilled a web-based questionnaire, consisting of the Composite Scale of Morningness (CSM), Mood Disorder Questionnaire (MDQ), Hypomania Checklist-32 (HCL-32) and the Temperament Evaluation of the Memphis, Pisa and San Diego-Autoquestionnaire (TEMPS-A). The role of temperamental traits in the relationship between morningness-eveningness and bipolarity was assessed using mediation analysis.

RESULTS

Morningness is correlated with lower bipolarity measured by the MDQ and HCL-32, and to lower scores of depressive, cyclothymic, irritable and anxious temperaments of the TEMPS-A. There is no significant association between morningness and hyperthymic traits. Cyclothymic and irritable traits are full mediators of the association between chronotype and bipolarity, influencing bipolarity independently from circadian preferences. Depressive and anxious traits are partial mediators of this association, increasing the effect of eveningness on bipolarity.

LIMITATIONS

The indirectness of the findings in the web-based study and disproportion of participants' gender.

CONCLUSIONS

Our study confirmed that eveningness is associated with bipolarity. In case of depressive and anxious temperaments, bipolarity is associated stronger with eveningness than with the TEMPS-A scores. On the other hand, cyclothymic and irritable temperaments were associated with bipolarity independently from circadian preferences.

Delayed sleep phase syndrome and bipolar disorder: Pathogenesis and available common biomarkers

Circadian rhythm disturbances are common in bipolar affective disorder (BD). Delayed sleep-wake phase syndrome (DSWPD) is the most prevalent circadian rhythm sleep-wake disorder (CRSWDs) and is frequently observed in BD. It is unclear whether DSWPD in BD is an independent process or is a consequence of BD. In this hypothetical review, we discuss the overlap between BD and DSWPD and potential common biomarkers for DSWPD and BD. The review will include a discussion of the genetics of DSWPD and BD. Biomarkers elucidating the pathophysiological processes occurring in these two disorders may offer insight into the etiology and prognosis of both conditions.

Solar insolation in springtime influences age of onset of bipolar I disorder

OBJECTIVE

To confirm prior findings that the larger the maximum monthly increase in solar insolation in springtime, the younger the age of onset of bipolar disorder.

METHOD

Data were collected from 5536 patients at 50 sites in 32 countries on six continents. Onset occurred at 456 locations in 57 countries. Variables included solar insolation, birth-cohort, family history, polarity of first episode and country physician density.

RESULTS

There was a significant, inverse association between the maximum monthly increase in solar insolation at the onset location, and the age of onset. This effect was reduced in those without a family history of mood disorders and with a first episode of mania rather than depression. The maximum monthly increase occurred in springtime. The youngest birth-cohort had the youngest age of onset. All prior relationships were confirmed using both the entire sample, and only the youngest birth-cohort (all estimated coefficients P < 0.001).

CONCLUSION

A large increase in springtime solar insolation may impact the onset of bipolar disorder, especially with a family history of mood disorders. Recent societal changes that affect light exposure (LED lighting, mobile devices backlit with LEDs) may influence adaptability to a springtime circadian challenge.

Examining the Behavioural Sleep-Wake Rhythm in Adults with Autism Spectrum Disorder and No Comorbid Intellectual Disability

This study aimed to examine the behavioural sleep-wake rhythm in 36 adults with autism spectrum disorder (ASD) and to determine the prevalence of circadian sleep-wake rhythm disorders compared to age- and sex-matched controls. Participants completed an online questionnaire battery, a 14-day sleep-wake diary and 14-day actigraphy assessment. The results indicated that a higher proportion of adults with ASD met criteria for a circadian rhythm sleep-wake disorder compared to control adults. In particular, delayed sleep-wake phase disorder was particularly common in adults with ASD. Overall the findings suggest that individuals with ASD have sleep patterns that may be associated with circadian rhythm disturbance; however factors such as employment status and co-morbid anxiety and depression appear to influence their sleep patterns.

Circadian rhythm sleep-wake disorders as predictors for bipolar disorder in patients with remitted mood disorders

BACKGROUND

Circadian rhythm dysfunction is thought to play a key role in the pathogenesis of bipolar disorder (BD). We focused on circadian rhythm sleep-wake disorders (CRSWD) as possible predictors for bipolar disorder in patients with remitted mood disorders.

METHOD

One hundred four BD (41 type I and 63 type II) outpatients and 73 age- and sex-matched major depressive disorder (MDD) outpatients participated in this study. The subjects were asked to answer questionnaires including demographic variables, clinical course of the disorder, and family history of psychiatric disorders. Severity of mood status was evaluated by the Montgomery-Åsberg Depression Rating Scale and Young Mania Rating Scale. CRSWD was diagnosed by clinical interview and sleep logs based on the International Classification of Sleep Disorders, third edition.

RESULTS

The rate of CRSWD in BD subjects was significantly higher than that in MDD subjects (33.7% vs 9.6%; P < 0.001). A multiple logistic regression analysis revealed that comorbid CRSWD (OR = 3.35, 95% CI = 1.24 - 9.07; P = 0.018), two or more previous mood episodes within the past year (OR = 3.57, 95% CI = 1.10 - 11.63; P = 0.035), and antidepressant-related switch to mania/hypomania (OR = 10.01, 95% CI = 1.20 - 83.52; P = 0.033) were significantly associated with BD in patients with remitted mood disorders.

CONCLUSION

CRSWD, as well as other factors, could be diagnostic predictors for BD in patients with remitted mood disorders. Combinations of these factors might be useful for predicting a BD diagnosis among the mood disorders in a clinical setting.

Suicidality in sleep disorders: prevalence, impact, and management strategies

Sleep disturbances are associated with suicide-related thoughts and behaviors, and the incidence of sleep concerns and suicide has increased recently in the US. Most published research exploring the sleep-suicidality relation is focused on select sleep disorders, with few reviews offering a comprehensive overview of the sleep-suicidality literature. This narrative review broadly investigates the growing research literature on sleep disorders and suicidality, noting the prevalence of suicide ideation and nonfatal and fatal suicide attempts, the impact of several sleep disorders on suicide risk, and potential sleep-disorder management strategies for mitigating suicide risk. Aside from insomnia symptoms and nightmares, there exist opportunities to learn more about suicide risk across many sleep conditions, including whether sleep disorders are associated with suicide risk independently of other psychiatric conditions or symptoms. Generally, there is a lack of randomized controlled trials examining the modification of suicide risk via evidence-based sleep interventions for individuals with sleep disorders.

History of Lifetime suicide attempt in bipolar I disorder: its correlates and effect on illness course

OBJECTIVES

To identify the prevalence and correlates of bipolar I patients with a lifetime history of suicide attempt.

MATERIALS AND METHODS

Bipolar I disorder was diagnosed in 150 patients as per DSM-IV-TR criteria. Their lifetime suicide risk was assessed using the Columbia Suicide Severity Rating Scale. NIMH retrospective Life Chart Methodology was used to chart the illness course. Medication Adherence Rating Scale (MARS) and Pittsburgh Sleep Quality Index (PSQI) were used to assess the recent adherence and subjective sleep quality, respectively. The suicide attempters were compared with non-attempters on individual variables.

RESULTS

Around 23% had a positive lifetime history of suicide attempt. They were predominantly female, had an index (first ever) episode of depression, spent more proportion of time being ill, especially in depressive or mixed episode phase. Comorbid substance use disorder along with suicidal attempts was seen only in males. Suicide attempters displayed poor medication adherence attitudes for medications taken during the past week and reported impaired sleep quality for the previous month.

CONCLUSIONS

A positive history of lifetime suicide attempt was significantly associated with a worse course of bipolar I disorder. Effective treatment of depressive episodes, addressing non-adherence, substance use and sleep problems can reduce the suicide risk in such patients. Retrospective design of the study and recall bias are some of the limitations.

Effect of aripiprazole on non-24-hour sleep-wake rhythm disorder comorbid with major depressive disorder: a case report

BACKGROUND

Patients with non-24-hour sleep-wake rhythm disorder (N24SWD) exhibit a sleep pattern that is asynchronous with the external light-dark cycle, typically involving a cycling, relapsing-remitting pattern of sleep disturbances, including nighttime insomnia and daytime sleepiness. Here, we report the case of a patient with N24SWD comorbid with major depressive disorder, who was successfully treated with a low dose of aripiprazole.

CASE PRESENTATION

A 47-year-old female presented with an 8-year complaint of difficulty falling asleep and waking up in the morning. The patient was diagnosed with major depressive disorder at the age of 35 years and was treated with various antidepressants since that time. At the age of 40 years, the patient's sleep-wake cycle began to extend without exacerbation of depressive symptoms. The patient was diagnosed with N24SWD at the age of 43 years. Ramelteon 8 mg/d and then melatonin 1 mg/d were administered, but these did not provide effective treatment. In January 2016, after treatment with aripiprazole 3 mg/d in the morning for 4 weeks, the patient's sleep-wake cycle became markedly synchronized to the environmental light-dark cycle. Her sleep-wake cycle remained synchronized when the same dose of aripiprazole was administered for at least 6 months.

CONCLUSION

Treatment-refractory asynchrony of the sleep-wake cycle in an N24SWD patient with depression was successfully treated with aripiprazole. Although the detailed mechanism of action is unclear, aripiprazole may be an appropriate treatment for patients with circadian rhythm sleep-wake disorders.

Possible association between SIRT1 single nucleotide polymorphisms and predisposition to antisocial personality traits in Chinese adolescents

Accumulating evidence suggests an association between the SIRT1 gene and human psychiatric disorders. The aim of the study was to investigate the association between SIRT1 and predisposition to antisocial personality traits (ASP) in Chinese adolescents. Participants consisted of 327 controls and 261 juvenile offenders who were diagnosed with predisposition to ASP according to the Personality Diagnostic Questionnaire. Four tag single nucleotide polymorphisms (tagSNPs) of SIRT1, namely rs12778366, rs7896005, rs10823112, and rs4746720, were genotyped. Association analysis between individual SNPs and ASP risk revealed the CC genotype of rs4746720 to be significantly associated with reduced risk of ASP (OR = 0.51, 95% CI = 0.33-0.77, adjusted P = 0.007). Haplotype analysis showed the TAAC haplotype was associated with reduced susceptibility to ASP (OR = 0.72, 95% CI = 0.57-0.91, P = 0.005). Moreover, rs4746720 variants were found to not only have a direct impact on ASP susceptibility but also modulate the effect of alcohol consumption (Y = 0.022X + 0.431 vs. Y = -0.066X + 0.387). The present study is the first to report a significant association between SIRT1 polymorphisms and ASP in adolescents. This finding is expected to aid in the development of effective interventions for this socially and personally costly disorder.