Evening chronotype as a discrete clinical subphenotype in bipolar disorder

Sex differences in insomnia and hypersomnia complaints during major depressive episode: Results from a national sample

BACKGROUND

Sex differences in sleep disturbances during major depressive episodes (MDE) have been suggested. This study compares the prevalence, sociodemographic characteristics, and psychiatric comorbidity associated with sleep complaints specific to each sex among adults with MDE. These findings are crucial for precise diagnosis, personalized treatment, and improved clinical outcomes.

METHODS

In a large nationally representative prospective survey, we used multi-adjusted logistic regression models including sociodemographic characteristics, psychiatric comorbidity, and depression severity to examine whether associations differ between men and women.

RESULTS

Among women, 93.3 % reported at least one type of sleep complaints (i.e., trouble falling asleep, early morning awakening or hypersomnia) while 91.0 % of men did, with respectively 78.3 % and 77.2 % of insomnia complaints, and 46.2 % and 41.3 % of hypersomnia complaints. Women with sleep complaints were more likely to be black, with lower individual incomes, have histrionic personality disorder or a specific phobia. Conversely, men with sleep complaints were more likely to have a lifetime diagnosis of mania spectrum disorder, generalized anxiety disorder, drug use disorder, as well as dependent and schizotypal personality disorders. Surprisingly, being "never married" has emerged as a protective factor against sleep complaints in women, while posing as a risk factor in men compared to other marital statuses. Differences and specificities were also noted concerning subtypes of insomnia and hypersomnia complaints.

LIMITATIONS

The cross-sectional design means the associations found do not imply causality.

CONCLUSIONS

These findings provide insights into the complex relationship between sleep and depression in men and women, highlighting the need for personalized interventions.

The relationship between sleep and circadian patterns with risk for suicide in bipolar disorder varies by subtype

INTRODUCTION

Sleep and circadian disturbances play a crucial role in psychiatric disorders, especially mood disorders such as bipolar disorder. This study investigated the predictive value of self-reported sleep and circadian factors for suicide risk in individuals with bipolar type I and bipolar type II disorder.

METHODS

Data were collected from the Heinz C. Prechter Longitudinal Study of Bipolar Disorder. Suicide risk was evaluated using the Columbia Suicide-Severity Rating Scale, while the sleep and circadian factors were extracted from the Pittsburgh Sleep Quality Index, Hamilton Depression Rating Scale, and Munich Chronotype Questionnaire.

RESULTS

A stepwise selection procedure identified significant predictors for each group. Results showed that suicide risk in individuals with bipolar disorder type I was associated with insomnia, whereas risk in bipolar disorder type II was associated with evening chronotype.

CONCLUSION

These findings indicate that specific sleep and circadian disturbance variables confer unique risk for suicide in the subtypes of bipolar disorder. This highlights the importance of conducting a thorough sleep and circadian assessment in clinical practice and emphasizes the need for clinical trials investigating the impact of sleep and circadian interventions on mitigating suicide risk in individuals with bipolar disorder.

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.

Circadian phase instability in bipolar disorder: a neglected essence

Circadian system disruption is an essential but poorly understood feature of bipolar disorder (BD) and associated comorbidities. This forum article summarizes current evidence regarding the emerging concept of circadian phase instability (CPI) as a neglected phenomenon with possibly unique features in BD that could be harnessed to develop individually tailored chronobiological interventions.

Association of Sleep Pattern and Genetic Susceptibility with Obstructive Sleep Apnea: A Prospective Analysis of the UK Biobank

Purpose

The prevalence of obstructive sleep apnea (OSA) is high worldwide. This study aimed to quantify the relationship between the incidence of OSA and sleep patterns and genetic susceptibility.

Methods

A total of 355,133 white British participants enrolled in the UK Biobank between 2006 and 2010 with follow-up data until September 2021 were recruited. We evaluated sleep patterns using a customized sleep scoring method based on the low-risk sleep phenotype, defined as follows: morning chronotype, 7-8 hours of sleep per day, never/rarely experience insomnia, no snoring, no frequent daytime sleepiness, never/rarely nap, and easily getting up early. The polygenic risk score was calculated to assess genetic susceptibility to OSA. Cox proportional hazard models were used to evaluate the associations between OSA and sleep patterns and genetic susceptibility.

Results

During a mean follow-up of 12.57 years, 4618 participants were diagnosed with OSA (age: 56.83 ± 7.69 years, women: 31.3%). Compared with those with a poor sleep pattern, participants with a normal (HR: 0.42, 95% CI: 0.38-0.46), ideal (HR: 0.21, 95% CI: 0.19-0.24), or optimal (HR: 0.15, 95% CI: 0.12-0.18) sleep pattern were significantly more likely to have OSA. The genetic susceptibility of 173,239 participants was calculated, and the results showed that poor (HR: 3.67, 95% CI: 2.95-4.57) and normal (HR: 1.89, 95% CI: 1.66-2.16) sleep patterns with high genetic susceptibility can increase the risk for OSA.

Conclusion

This large-scale prospective study provides evidence suggesting that sleep patterns across seven low-risk sleep phenotypes may protect against OSA in individuals with varying degrees of genetic susceptibility.

The influence of childhood trauma and chronotype on suicide attempts in Chinese emerging adults with severe depressive symptoms

BACKGROUND

Studies have investigated how adults with severe depressive symptoms are more likely to attempt suicide, and these adults often have traumatic experiences and chaotic sleep/wake rhythms. Thus, this study using Latent class analysis aimed to investigate the relationship between childhood trauma class, chronotype, and suicide attempts among emerging adults with severe depressive symptoms.

METHODS

This study was conducted among emerging adults with severe depressive symptoms covering 63 Universities in Jilin Province, China. A total of 1,225 emerging adults (mean age = 19.6 ± 1.78) constructed the final sample. In addition to measuring socio-demographic characteristics, the Childhood Trauma Questionnaire-Short Form, the Single-Item Chronotyping, and a single item for suicide attempts were used to evaluate childhood trauma, chronotype, and suicide attempts, respectively. Latent class analysis was applied to identify the classes of childhood trauma within emerging adults who had severe depressive symptoms. Hierarchical logistic regression models were run to investigate the effects of socio-demographic characteristics, chronotype, and childhood trauma class on suicide attempts.

RESULTS

Three latent classes were identified: the Low-risk for childhood trauma class, the Neglect class, and the High-risk for childhood abuse class. Those who suffered sexual, emotional, and physical abuse at the same time were divided into the High-risk for childhood abuse class, and were significantly more likely to experience suicide attempts than those in the Neglect class (OR = 1.97, 95%CI = 1.34-2.89, p < 0.001) and the Low-risk for childhood trauma class (OR = 2.28, 95% CI = 1.50-3.46, p < 0.001). In terms of chronotype, the results showed that the chaotic type was a risk factor for suicide attempts when compared with the evening type (OR = 0.46, 95%CI = 0.27-0.78, p < 0.01), the moderately active type (OR = 0.53, 95%CI = 0.31-0.89, p < 0.05), and the daytime type (OR = 0.42, 95%CI = 0.21-0.86, p < 0.05). Overall, the significant risk factors for suicide attempts included being female, living in an urban area, having experienced sexual, emotional, and physical abuse simultaneously, and having a chaotic chronotype.

CONCLUSION

Emerging adults suffering sexual, emotional, and physical abuse at the same time and identifying with chaotic chronotype showed a higher risk of attempting suicide. The findings provided a clinical reference to quickly identify those at high risk of suicide attempts among emerging adults with severe depressive symptoms.

Chronotype is differentially associated with lifetime mood and panic-agoraphobic spectrum symptoms in patients with bipolar disorder and healthy controls

OBJECTIVE

Although the association between chronotype and mood disorders has been consistently reported, conversely, attempts to measure the association between chronotype and anxiety symptoms have generated inconsistent results. We aimed at evaluating whether chronotype (assessed through subjective and objective measures) is associated with lifetime mood and panic-agoraphobic spectrum symptoms in healthy controls (HCs) and in patients with bipolar disorder (BD).

METHODS

Overall, 173 subjects, patients with BD in euthymic phase (n = 76) and HC (n = 97), were evaluated through the reduced Morningness-Eveningness Questionnaire (rMEQ), actigraphy monitoring and mood and panic-agoraphobic spectrum self-report (MOODS-SR and PAS-SR). The discrepancy between objective (actigraphic-based) versus subjective (rMEQ-based) circadian typology was estimated through the Circadian Classification Discrepancy Index (CCDI).

RESULTS

rMEQ-based evening chronotype (ET) was associated with higher scores in MOODS-SR depressive and rhythmicity and vegetative functions domains in HC and BD.Both ET and morning chronotypes (MT) were associated with higher PAS-SR scores in BD only. Actigraphic-based MT was associated with higher MOODS-SR depressive scores in HC. Likewise, the discrepancy between actigraphic-based and rMEQ-based circadian typology was associated with depressive symptoms in HC only.

CONCLUSION

Self-reported ET was consistently associated with mood symptoms, while associations with panic-agoraphobic symptoms only emerged in BD and involved both extreme chronotypes. The discrepancy between the preferred circadian typology (rMEQ-based) and the actual one (actigraphic-based) could contribute to depressive symptoms in HC. These results pave the way for interventional studies targeting circadian typology in an attempt to prevent or treat mental health disorders.

Chronotype is associated with affective temperaments, clinical severity and worse treatment outcomes in bipolar disorders: results from a two-center, cross-sectional study

OBJECTIVE

The present study was aimed at investigating the clinical correlates of evening chronotype in a population of subjects suffering from bipolar disorders (BD).

METHODS

We assessed chronotype using the Morningness-Eveningness Questionnaire. We administered the brief Temperament Evaluation of Memphis, Pisa, and San Diego, the Barratt Impulsiveness Scale, and the Alda Scale to evaluate affective temperaments, impulsiveness, and response to mood stabilisers. We performed bivariate analyses and ran a logistic regression model to analyse clinical variables associated with evening chronotype.

RESULTS

In our sample (n = 178), subjects with an evening chronotype (n = 56, 31.5%) more often suffered from BD type I and reported higher prevalence of seasonality, antidepressant-induced mood switches, psychotic, aggressive, mixed, and anxiety features, and substance use disorders. The number of lifetime suicide attempts and mood episodes was higher in this subgroup. Depressive, cyclothymic, irritable, and anxious temperament scores were higher among evening-chronotype subjects, who also displayed greater levels of impulsiveness and worse treatment response. At the logistic regression, evening chronotype was associated with depressive and irritable temperaments.

CONCLUSIONS

Subjects with evening chronotype display higher clinical severity and worse BD course. Clinicians should evaluate the presence of evening chronotype in BD subjects, especially in those with irritable or depressive temperament.Key pointsEvening chronotype is a frequent clinical feature in subjects suffering from bipolar disorders (BD);Affective temperaments, particularly depressive and irritable, are associated with evening chronotype in BD;Evening chronotype underpins higher severity of the clinical picture in BD, as well as a worse response to mood stabiliser treatment;Circadian preferences should be systematically assessed in subjects suffering from BD, with particular attention to evening preference.

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.

Clinical characterization of patients with bipolar disorder and a history of asthma: An exploratory study

INTRODUCTION

Bipolar disorder (BD) and asthma are leading causes of morbidity in the US and frequently co-occur.

OBJECTIVES

We evaluated the clinical features and comorbidities of patients with BD and a history of asthma.

METHODS

In a cross-sectional analysis from the Mayo Clinic Bipolar Biobank, we explored the clinical characteristics of the BD and an asthma phenotype and fitted a multivariable regression model to identify risk factors for asthma.

RESULTS

A total of 721 individuals with BD were included. From these, 140 (19%) had a history of asthma. In a multivariable model only sex and evening chronotype were significant predictors of asthma with the odds ratios and 95% confidence intervals being 1.65 (1.00, 2.72; p=0.05) and 1.99 (1.25, 3.17; p < 0.01), respectively. Individuals with asthma had higher odds of having other medical comorbidities after adjusting for age, sex, and site including hypertension (OR = 2.29 (95% CI 1.42, 3.71); p < 0.01), fibromyalgia (2.29 (1.16, 4.51); p=0.02), obstructive sleep apnea (2.03 (1.18, 3.50); p=0.01), migraine (1.98 (1.31, 3.00); p < 0.01), osteoarthritis (2.08 (1.20, 3.61); p < 0.01), and COPD (2.80 (1.14, 6.84); p=0.02). Finally, individuals currently on lithium were less likely to have a history of asthma (0.48 (0.32, 0.71); p < 0.01).

CONCLUSION

A history of asthma is common among patients with BD and is associated with being female and having an evening chronotype, as well as with increased odds of having other medical comorbidities. A lower likelihood of a history of asthma among those currently on lithium is an intriguing finding with potential clinical implications that warrants further study.

Exploratory Study on the Associations between Lifetime Post-Traumatic Stress Spectrum, Sleep, and Circadian Rhythm Parameters in Patients with Bipolar Disorder

The present study aimed at exploring whether lifetime post-traumatic stress spectrum symptoms are associated with chronotype in patients with bipolar disorder (BD). Moreover, we explored whether the chronotype can moderate the potential associations between lifetime post-traumatic stress spectrum symptoms and rest-activity circadian and sleep-related parameters. A total of 74 BD patients were administered the Trauma and Loss Spectrum Self-Report (TALS-SR) lifetime version for lifetime post-traumatic stress spectrum symptoms, the Pittsburgh Sleep Quality Index (PSQI) for self-reported sleep quality, and the Reduced Morningness-Eveningness Questionnaire (rMEQ) to discriminate evening chronotypes (ETs), neither chronotype (NT), and morning chronotype (MT). Actigraphic monitoring was used to objectively evaluate sleep and circadian parameters. Patients classified as ET reported significantly higher scores in the re-experiencing domain, as well as poorer sleep quality, lower sleep efficiency, increased wake after sleep onset, and delayed mid-sleep point compared with both NT and MT (p-value ≤ 0.05). Moreover, ET presented significantly higher scores in the TALS-SR maladaptive coping domain than NT and lower relative amplitude than MT (p-value ≤ 0.05). Moreover, higher TALS-SR total symptomatic domains scores were significantly correlated with poor self-reported sleep quality. Regression analyses showed that the PSQI score maintained the association with the TALS total symptomatic domains scores after adjusting for potentially confounding factors (age and sex) and that no interaction effect was observed between the chronotype and the PSQI. Conclusions: This exploratory study suggests that patients with BD classified as ET showed significantly higher lifetime post-traumatic stress spectrum symptoms and more disrupted sleep and circadian rhythmicity with respect to other chronotypes. Moreover, poorer self-reported sleep quality was significantly associated with lifetime post-traumatic stress spectrum symptoms. Further studies are required to confirm our results and to evaluate whether targeting sleep disturbances and eveningness can mitigate post-traumatic stress symptoms in BD.

Regional shape alteration of left thalamus associated with late chronotype in young adults

Chronotype reflects individual differences in circadian rhythms and influences individual psychology and behavior. Previous studies found altered subcortical structures are closely related to individual chronotypes. However, these studies have been conducted mainly using voxel-based morphometry and traditional volume measurement methods with certain limitations. This study aimed to investigate subcortical aberrant volume and shape patterns in late chronotypes (LC) young adults compared to early chronotypes (EC) young adults. Magnetic resonance imaging (MRI) scanning and chronotype assessment were performed once for all participants, including 49 LC young adults and 49 matched EC young adults. The morningness and eveningness preferences were assessed using the Chronotype Questionnaire. A vertex-wise shape analysis was conducted to analyze structural MRI data. There were no significant differences in brain tissue volume and subcortical structural volume between groups. LC young adults showed significant regional shape atrophy in the left ventral posterior thalamus compared to EC individuals. A significant correlation was found between the regional shape atrophy of left ventral posterior thalamus and the score of Chronotype Questionnaire in LC young adults. Regional shape alteration of left thalamus was closely related to the chronotype, and LC may be a potential risk factor for sleep-related behavioral and mental problems in young adults. However, the predominantly female sample and the failure to investigate the effect of chronotype on the subcortical structure-function network are limitations of this study. Further prospective studies are needed to investigate the temporal characteristics of thalamic shape changes and consequent behavioral and psychiatric problems in adults with LC.

The Mediating Role of Time Perspective in the Relationship between Chronotype and Suicide in Bipolar Disorder

(1) Background: Suicide in patients with bipolar disorder (BD) is related to the chronotype of the person from a biological perspective. However, it is not known whether there is a relationship between suicide and psychological time in BD. The aim of our study was to evaluate the relationship between time perspective (TP) and suicide and the effect of TP on the relationship between suicide and chronotype in euthymic patients with BD. (2) Methods: We included 150 BD patients and 84 healthy controls in this cross-sectional study. We administered the Young Mania Rating Scale (YMRS), Hamilton Depression Rating Scale (HDRS), Beck Scale for Suicidal Ideation (BSSI), Zimbardo Time Perspective Inventory (ZTPI), and Morning−Evening Questionnaire (MEQ). (3) Results: There was a statistically significant difference between the median scores of past negative TP, present fatalistic TP, future TP, and MEQ total score (p < 0.001, p < 0.001, p = 0.010, and p = 0.020, respectively). There was a significant correlation between past negative TP, future TP, MEQ scores, and BSSI scores in the patient group (p < 0.001, p = 0.018, and p = 0.028, respectively). An inverse and significant relationship between the MEQ total score and BSSI score and TP types had a mediator role in this relationship. (4) Conclusions: Our study shows that TP, which evaluates time from a psychological perspective, has a direct relationship with suicidal ideation and a mediating role in the relationship between chronotype and suicide. According to our results, we can conclude that ZTPI can also be used to evaluate the risk of suicidality in patients with BD. Appropriate therapy methods for TP may help to prevent some suicide attempts.

The relationship between morningness-eveningness and mood symptoms and quality of life in euthymic state of mood disorders: Results from a prospective observational cohort study

BACKGROUND

The clinical importance of morningness-eveningness, especially in mood disorders, is prevailing. The differential relation of chronotype with diagnoses of early-onset mood disorders, mood symptoms, anxiety, and quality of life was evaluated.

METHODS

Early-onset mood disorder patients [n = 419; 146 major depressive disorder (MDD); 123 bipolar I disorder (BDI); 150 bipolar II disorder (BDII)] from the Mood Disorder Cohort Research Consortium were assessed for chronotype using the composite scale for morningness (CSM) and its association with clinical variables obtained during the clinician-verified euthymic state.

RESULTS

The mean total CSM of BDI was significantly higher than MDD and BDII (p < 0.001). In all types of mood disorders, higher total CSM was associated with lower Quick inventory of depressive symptomatology (p < 0.005) and higher WHO quality of life (p < 0.005). Such negative correlations between the total CSM and Montgomery-Asberg depression rating were significant in MDD and BDI (p < 0.05) and marginally significant in BDII (p = 0.077). CSM was a significant contributor to quality of life in BDI (p < 0.001) and BDII (p = 0.011), but it was not for MDD.

LIMITATIONS

The defined 'euthymic state' that may not fully reflect the remission of episode; limited generalizability due to clinical characteristic of early-onset mood disorder; the disparity between diurnal preference measured by the CSM and chronotype; possible effects of the last mood episode polarity and medication; and, lack of control group.

CONCLUSION

Less eveningness was associated with less severe depressive symptoms and better quality of life. This suggests that morningness may reduce residual depressive symptoms and recover function of patients.

The genetics of bipolar disorder with obesity and type 2 diabetes

BACKGROUND

Bipolar disorder (BD) presents with high obesity and type 2 diabetes (T2D) and pathophysiological and phenomenological abnormalities shared with cardiometabolic disorders. Genomic studies may help define if they share genetic liability. This selective review of BD with obesity and T2D will focus on genomic studies, stress their current limitations and guide future steps in developing the field.

METHODS

We searched electronic databases (PubMed, Scopus) until December 2021 to identify genome-wide association studies, polygenic risk score analyses, and functional genomics of BD accounting for body mass index (BMI), obesity, or T2D.

RESULTS

The first genome-wide association studies (GWAS) of BD accounting for obesity found a promising genome-wide association in an intronic gene variant of TCF7L2 that was further replicated. Polygenic risk scores of obesity and T2D have also been associated with BD, yet, no genetic correlations have been demonstrated. Finally, human-induced stem cell studies of the intronic variant in TCF7L2 show a potential biological impact of the products of this genetic variant in BD risk.

LIMITATIONS

The narrative nature of this review.

CONCLUSIONS

Findings from BD GWAS accounting for obesity and their functional testing, have prompted potential biological insights. Yet, BD, obesity, and T2D display high phenotypic, genetic, and population-related heterogeneity, limiting our ability to detect genetic associations. Further studies should refine cardiometabolic phenotypes, test gene-environmental interactions and add population diversity.

A matter of time: A systematic scoping review on a potential role of the circadian system in binge eating behavior

Background

Emerging research suggests that food intake timing, eating behavior and food preference are associated with aspects of the circadian system function but the role that the circadian system may play in binge eating (BE) behavior in humans remains unclear.

Objective

To systematically evaluate the evidence for circadian system involvement in BE behavior.

Methods

Systematic searches of PubMed, EMBASE, and Scopus were performed for reports published from inception until May 2020 (PROSPERO Registration CRD42020186325). Searches were conducted by combining Medical Subject Headings related to the circadian system, BE behavior, and/or interventions. Observational and interventional studies in humans with BE behavior published in peer-review journals in the English language were included. Studies were assessed using quality and risk of bias tools (AXIS, ROB 2.0, or ROBINS).

Results

The search produced 660 articles, 51 of which were included in this review. Of these articles, 46 were observational studies and 5 were interventional trials. Evidence from these studies suggests that individuals with BE behavior tend to have more food intake, more binge cravings, and more BE episodes later in the day. Hormonal and day/night locomotor activity rhythm disturbances may be associated with BE behavior. Furthermore, late diurnal preference ("eveningness") was associated with BE behavior and chronobiological interventions that shift the circadian clock earlier (e.g., morning bright light therapy) were found to possibly decrease BE behavior. Substantive clinical overlap exists between BE and night eating behavior. However, there is a significant knowledge gap regarding their potential relationship with the circadian system. Limitations include the lack of studies that use best-established techniques to assess the chronobiology of BE behavior, heterogeneity of participants, diagnostic criteria, and study design, which preclude a meta-analytic approach.

Conclusion

Current evidence, although limited, suggests that the circadian system may play a role in the etiology of BE behavior. Further mechanistic studies are needed to fully characterize a potential role of the circadian system in BE behavior. A chronobiological approach to studying BE behavior may lead to identification of its neurobiological components and development of novel therapeutic interventions.

Systematic review registration

[https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020186325], identifier [CRD42020186325].

The Mediation Effect of Peripheral Biomarkers of Calcium Metabolism and Chronotypes in Bipolar Disorder Psychopathology

Calcium (Ca++) metabolism may be impaired in several psychiatric diseases. We hypothesize that calcium imbalance might also correlate with a specific chronotype and could be recognized as a marker of illness severity in bipolar disorder (BD). We aimed to (1) identify the association between calcium imbalance and a specific chronotype in a cohort of BD patients, and (2) test the mediation role of high parathyroid hormone (PTH) levels towards a specific chronotype and illness severity in BD patients. Patients’ socio-demographic and clinical characteristics were collected with an ad-hoc schedule. We administered the Hamilton Depression Rating Scale (HAM-D), the Hamilton Rating Scale for Anxiety (HAM-A), the Young Mania Rating Scale (YMRS), and the Morningness Eveningness Questionnaire (MEQ). 100 patients affected by BD were recruited. The Kruskal-Wallis test showed a significant difference between the three MEQ groups in PTH levels (p < 0.001) and vitamin D levels (p = 0.048) but not in Ca++ levels (p = 0.426). Dwass-Steel-Critchlow-Fligner Pairwise analyses performed concerning three MEQ groups revealed significantly higher scores on PTH levels in MEQ-E subjects compared to MEQ-M and MEQ-I (in both cases, p < 0.001). No differences emerged between calcium levels among the three chronotypes. The mediation analysis has shown that elevated PTH levels are directly influenced by more severe HAM-A, HAM-D, and YMRS scores. MEQ-E could be a marker related to BD and predispose to various factors influencing mood symptoms. The combination of vitamin D therapy in MEQ-E may help to improve prognosis in this subtype of patients affected by BD.

The impact of lithium on circadian rhythms and implications for bipolar disorder pharmacotherapy

Bipolar disorder (BD) is characterized by disrupted circadian rhythms affecting sleep, arousal, and mood. Lithium is among the most effective mood stabilizer treatments for BD, and in addition to improving mood symptoms, stabilizes sleep and activity rhythms in treatment responsive patients. Across a variety of experimental models, lithium has effects on circadian rhythms. However, uncertainty exists as to whether these actions directly pertain to lithium's therapeutic effects. Here, we consider evidence from mechanistic studies in animals and cells and clinical trials in BD patients that identify associations between circadian rhythms and the therapeutic effects of lithium. Most evidence indicates that lithium has effects on cellular circadian rhythms and increases morningness behaviors in BD patients, changes that may contribute to the therapeutic effects of lithium. However, much of this evidence is limited by cross-sectional analyses and/or imprecise proxy markers of clinical outcomes and circadian rhythms in BD patients, while mechanistic studies rely on inference from animals or small numbers of patients . Further study may clarify the essential mechanisms underlying lithium responsive BD, better characterize the longitudinal changes in circadian rhythms in BD patients, and inform the development of therapeutic interventions targeting circadian rhythms.

Chronotype, circadian rhythm, and psychiatric disorders: Recent evidence and potential mechanisms

The circadian rhythm is crucial for physiological and behavioral functions. Chronotype, which represents individual preferences for activity and performance, is associated with human health issues, particularly psychiatric disorders. This narrative review, which focuses on the relationship between chronotype and mental disorders, provides an insight into the potential mechanism. Recent evidence indicates that (1) the evening chronotype is a risk factor for depressive disorders and substance use disorders, whereas the morning chronotype is a protective factor. (2) Evening chronotype individuals with bipolar disorder tend to have more severe symptoms and comorbidities. (3) The evening chronotype is only related to anxiety symptoms. (4) The relationship between chronotype and schizophrenia remains unclear, despite increasing evidence on their link. (5) The evening chronotype is significantly associated with eating disorders, with the majority of studies have focused on binge eating disorders. Furthermore, the underlying mechanisms or influence factors are described in detail, including clock genes, brain characteristics, neuroendocrinology, the light/dark cycle, social factors, psychological factors, and sleep disorders. These findings provide the latest evidence on chronotypes and psychiatric disorders and serve as a valuable reference for researchers.

Prevalence and psychiatric comorbidities of night-eating behavior in obese bariatric patients: preliminary evidence for a connection between night-eating and bipolar spectrum disorders

PURPOSE

The co-occurrence of obesity, eating and mood disorders has been frequently reported in clinical and epidemiological settings. This study aimed to explore the prevalence of night-eating obese patients referred for bariatric surgery and to identify associated psychopathology and psychiatric comorbidity.

METHODS

The sample was composed of 121 obese patients consecutively enrolled between November 2010 and May 2012 during psychiatric evaluations for bariatric intervention. Clinical features and psychiatric diagnoses were collected. Night-eating was investigated through the administration of the Night-eating Questionnaires (NEQ) and was defined as the presence of self-reported evening hyperphagia and/or nocturnal ingestions. Binge-eating and purging behaviors and general psychopathology were respectively assessed using the Bulimic Investigatory Test, Edinburgh and the Symptom Checklist-90-Revised.

RESULTS

Night-eating was reported by twenty subjects (16.5%). Patients with night-eating behavior were significantly more frequently diagnosed with bipolar spectrum disorders and with comorbid eating and mood disorders in comparison with other patients. Night-eating patients showed significantly more binging/purging behaviors and greater severity of somatization, obsessive-compulsive symptoms, phobic anxiety, psychoticism and sleep disorders. Patients with bipolar disorder type 1 or 2 scored significantly higher than those without mood disorders at NEQ total score, mood/sleep and nocturnal ingestions subscales, but also scored significantly higher than other patients with mood disorders at the latter subscale.

CONCLUSION

Patients with evening hyperphagia and/or nocturnal ingestions should be carefully evaluated to detect possible bipolar spectrum disorders and other eating disorders. Prompt management of these conditions should be provided before bariatric interventions.

LEVEL OF EVIDENCE

V, cross-sectional descriptive study.

Chronotypes and circadian rest-activity rhythms in bipolar disorders: a meta-analysis of self- and observer rating scales

OBJECTIVE

Chronobiological models postulate that abnormalities in circadian rest/activity rhythms (CRAR) are core phenomena of bipolar disorders (BDs). We undertook a meta-analysis of published studies to determine whether self- or observer ratings of CRAR differentiate BD cases from comparators (typically healthy controls [HCs]).

METHOD

We undertook systematic searches of four databases to identify studies for inclusion in random effects meta-analyses and meta-regression analyses. Effect sizes (ES) for pooled analyses of self- and observer ratings were expressed as standardized mean differences with 95% confidence intervals (CIs).

RESULTS

The 30 studies meeting eligibility criteria included 2840 cases and 3573 controls. Compared with HC, BD cases showed greater eveningness (ES: 0.33; 95% CI: 0.12-0.54), lower flexibility of rhythms (ES: 0.36; 95% CI: 0.06-0.67), lower amplitude of rhythms (ES: 0.55; 95% CI: 0.39-0.70) and more disturbances across a range of CRAR (ES of 0.78-1.12 for general and social activities, sleep and eating patterns). Between study heterogeneity was high (I²  > 70%) and evidence indicated a potential publication bias for studies using the Biological Rhythms Interview of Assessment in Neuropsychiatry. Meta-regression analyses suggested significantly larger ES were observed in studies using observer ratings or including BD cases with higher levels of depressive symptoms.

CONCLUSION

This meta-analysis demonstrates that BD is associated with higher levels of self- or observer-rated CRAR disturbances compared with controls. However, further studies should examine the respective performance of individual instruments when used alone or in combination, to clarify their applicability and utility in clinical practice.

Quantifying daily rhythms with non-negative matrix factorization applied to mobile phone data

Human activities follow daily, weekly, and seasonal rhythms. The emergence of these rhythms is related to physiology and natural cycles as well as social constructs. The human body and its biological functions undergo near 24-h rhythms (circadian rhythms). While their frequencies are similar across people, their phases differ. In the chronobiology literature, people are categorized into morning-type, evening-type, and intermediate-type groups called chronotypes based on their tendency to sleep at different times of day. Typically, this typology builds on carefully designed questionnaires or manually crafted features of time series data on people’s activity. Here, we introduce a method where time-stamped data from smartphones are decomposed into components using non-negative matrix factorization. The method does not require any predetermined assumptions about the typical times of sleep or activity: the results are fully context-dependent and determined by the most prominent features of the activity data. We demonstrate our method by applying it to a dataset of mobile phone screen usage logs of 400 university students, collected over a year. We find four emergent temporal components: morning activity, night activity, evening activity and activity at noon. Individual behavior can be reduced to weights on these four components. We do not observe any clear categories of people based on the weights, but individuals are rather placed on a continuous spectrum according to the timings of their phone activities. High weights for the morning and night components strongly correlate with sleep and wake-up times. Our work points towards a data-driven way of characterizing people based on their full daily and weekly rhythms of activity and behavior, instead of only focusing on the timing of their sleeping periods.

Individual Circadian Preference, Eating Disorders and Obesity in Children and Adolescents: A Dangerous Liaison? A Systematic Review and a Meta-Analysis

BACKGROUND

Obesity and other eating disorders are an actual public health problem, especially in childhood and adolescents, and could be also related with chronotype. The aim of this systematic review was to determine the relationship between eating disorders, obesity and the different chronotypes in children and adolescents.

METHODS

A systematic review of observational studies evaluating young populations dealing with and evaluating chronotype was conducted. Electronic searches were performed in six international databases. A qualitative thematic-categorical analysis was carried out and a random-effects model was used for the quantitative analysis (meta-analysis).

RESULTS

Fifteen studies were included, but quantitative analysis was only carried out in three of them. Children and adolescents with an evening chronotype had higher body mass index, consumed more junk food or were more predisposed to suffer from food addiction and night eating syndrome.

CONCLUSIONS

Children and adolescents with evening chronotype had higher tendency to incorrect eating behaviors and were suffering from overweight/obesity. Environment but also lifestyle factors should be considered in the association between chronotype and eating disorders and obesity.

Revisiting the bipolar disorder with migraine phenotype: Clinical features and comorbidity

INTRODUCTION

To evaluate the prevalence and clinical correlates of lifetime migraine among patients with bipolar disorder (BD).

METHODS

In a cross-sectional study, we evaluated 721 adults with BD from the Mayo Clinic Bipolar Disorder Biobank and compared clinical correlates of those with and without a lifetime history of migraine. A structured clinical interview (DSM-IV) and a clinician-assessed questionnaire were utilized to establish a BD diagnosis, lifetime history of migraine, and clinical correlates.

RESULTS

Two hundred and seven (29%) BD patients had a lifetime history of migraine. BD patients with migraine were younger and more likely to be female as compared to those without migraine (p values <0.01). In a multivariate logistic regression model, younger age (OR=0.98, p<0.01), female sex (OR=2.02, p<0.01), higher shape/weight concern (OR=1.04, p=0.02), greater anxiety disorder comorbidities (OR=1.24, p<0.01), and evening chronotype (OR=1.65, p=0.03) were associated with migraine. In separate regression models for each general medical comorbidity (controlled for age, sex, and site), migraines were significantly associated with fibromyalgia (OR=3.17, p<0.01), psoriasis (OR=2.65, p=0.03), and asthma (OR=2.0, p<0.01). Participants with migraine were receiving ADHD medication (OR=1.53, p=0.05) or compounds associated with weight loss (OR=1.53, p=0.02) at higher rates compared to those without migraine.

LIMITATIONS

Study design precludes determination of causality. Migraine subtypes and features were not assessed.

CONCLUSIONS

Migraine prevalence is high in BD and is associated with a more severe clinical burden that includes increased comorbidity with pain and inflammatory conditions. Further study of the BD-migraine phenotype may provide insight into common underlying neurobiological mechanisms.

Late chronotype predicts more depressive symptoms in bipolar disorder over a 5 year follow-up period

BACKGROUND

There is increasing evidence that bipolar disorder is influenced by circadian timing, including the timing of sleep and waking activities. Previous studies in bipolar disorder have shown that people with later timed daily activities, also known as late chronotypes, are at higher risk for subsequent mood episodes over the following 12-18 months. However, these studies were limited to euthymic patients and smaller sample sizes. The aim of the current study was to further examine baseline chronotype as a potentially important predictor of mood-related outcomes in a larger sample of individuals with bipolar disorder and over the longest follow up period to date, of 5 years. Participants included 318 adults diagnosed with bipolar I and II (19-86 years) who were enrolled in the Prechter Longitudinal Study of Bipolar Disorder.

RESULTS

Participants with a late chronotype were found to be more likely to have mild to more severe depressive symptoms (PHQ-9 ≥ 5) as captured with PHQ-9 assessments every 2 months over the 5 year follow up period. This higher risk for depressive symptoms remained even after adjusting for age, sex and mood at baseline. Additionally, late chronotypes reported fewer hypomania/mania episodes during the 5 year follow up, as derived from clinical interviews every two years.

CONCLUSIONS

These results highlight the potential clinical usefulness of a single self-report question, in identifying patients at risk for a more depressive mood course. The results also suggest that circadian phase advancing treatments, that can shift circadian timing earlier, should be explored as a means to reduce depressive symptoms in late chronotypes with bipolar disorder.

Enlightened: addressing circadian and seasonal changes in photoperiod in animal models of bipolar disorder

Bipolar disorders (BDs) exhibit high heritability and symptoms typically first occur during late adolescence or early adulthood. Affected individuals may experience alternating bouts of mania/hypomania and depression, with euthymic periods of varying lengths interspersed between these extremes of mood. Clinical research studies have consistently demonstrated that BD patients have disturbances in circadian and seasonal rhythms, even when they are free of symptoms. In addition, some BD patients display seasonal patterns in the occurrence of manic/hypomanic and depressive episodes as well as the time of year when symptoms initially occur. Finally, the age of onset of BD symptoms is strongly influenced by the distance one lives from the equator. With few exceptions, animal models useful in the study of BD have not capitalized on these clinical findings regarding seasonal patterns in BD to explore molecular mechanisms associated with the expression of mania- and depression-like behaviors in laboratory animals. In particular, animal models would be especially useful in studying how rates of change in photoperiod that occur during early spring and fall interact with risk genes to increase the occurrence of mania- and depression-like phenotypes, respectively. Another unanswered question relates to the ways in which seasonally relevant changes in photoperiod affect responses to acute and chronic stressors in animal models. Going forward, we suggest ways in which translational research with animal models of BD could be strengthened through carefully controlled manipulations of photoperiod to enhance our understanding of mechanisms underlying seasonal patterns of BD symptoms in humans. In addition, we emphasize the value of incorporating diurnal rodent species as more appropriate animal models to study the effects of seasonal changes in light on symptoms of depression and mania that are characteristic of BD in humans.

A Causal Web between Chronotype and Metabolic Health Traits

Observational and experimental evidence has linked chronotype to both psychological and cardiometabolic traits. Recent Mendelian randomization (MR) studies have investigated direct links between chronotype and several of these traits, often in isolation of outside potential mediating or moderating traits. We mined the EpiGraphDB MR database for calculated chronotype–trait associations (p-value < 5 × 10⁻⁸). We then re-analyzed those relevant to metabolic or mental health and investigated for statistical evidence of horizontal pleiotropy. Analyses passing multiple testing correction were then investigated for confounders, colliders, intermediates, and reverse intermediates using the EpiGraphDB database, creating multiple chronotype–trait interactions among each of the the traits studied. We revealed 10 significant chronotype–exposure associations (false discovery rate < 0.05) exposed to 111 potential previously known confounders, 52 intermediates, 18 reverse intermediates, and 31 colliders. Chronotype–lipid causal associations collided with treatment and diabetes effects; chronotype–bipolar associations were mediated by breast cancer; and chronotype–alcohol intake associations were impacted by confounders and intermediate variables including known zeitgebers and molecular traits. We have reported the influence of chronotype on several cardiometabolic and behavioural traits, and identified potential confounding variables not reported on in studies while discovering new associations to drugs and disease.

Association between the Arylalkylamine N-Acetyltransferase (AANAT) Gene and Seasonality in Patients with Bipolar Disorder

OBJECTIVE

Bipolar disorder (BD) is complex genetic disorder. Therefore, approaches using clinical phenotypes such as biological rhythm disruption could be an alternative. In this study, we explored the relationship between melatonin pathway genes with circadian and seasonal rhythms of BD.

METHODS

We recruited clinically stable patients with BD (n=324). We measured the seasonal variation of mood and behavior (seasonality), and circadian preference, on a lifetime basis. We analyzed 34 variants in four genes (MTNR1a, MTNR1b, AANAT, ASMT) involved in the melatonin pathway.

RESULTS

Four variants were nominally associated with seasonality and circadian preference. After multiple test corrections, the rs116879618 in AANAT remained significantly associated with seasonality (corrected p=0.0151). When analyzing additional variants of AANAT through imputation, the rs117849139, rs77121614 and rs28936679 (corrected p=0.0086, 0.0154, and 0.0092) also showed a significant association with seasonality.

CONCLUSION

This is the first study reporting the relationship between variants of AANAT and seasonality in patients with BD. Since AANAT controls the level of melatonin production in accordance with light and darkness, this study suggests that melatonin may be involved in the pathogenesis of BD, which frequently shows a seasonality of behaviors and symptom manifestations.

Meta-analysis of sleep deprivation in the acute treatment of bipolar depression

BACKGROUND

Sleep deprivation (SD) is an antidepressant intervention with multiple administration formats that has been investigated primarily with uncontrolled clinical trials and qualitative reviews of the literature. The validity and applicability of these findings to the treatment of bipolar depression (BPD) is uncertain.

METHODS

A PRISMA-based systematic review of the literature and meta-analysis were conducted to determine the efficacy of SD in the treatment of BPD and to identify moderator variables that influence response rate.

RESULTS

From a sample of 15 studies covering 384 patients, the overall, mean response rate to SD was 47.6% (CI 36.0%, 59.5%). This response rate compared post-SD to pre-SD depression scores, and not to a placebo control condition. Of several potential moderating variables examined, the use of adjunctive pharmacotherapy achieved statistical significance with response rates of 59.4% [CI 48.5, 69.5] for patients using adjunctive medication vs 27.4% [CI 17.8, 39.8] for patients not using adjunctive medication.

CONCLUSIONS

This meta-analysis of SD in the treatment of BPD found an overall, response rate of almost 50%, reinforcing earlier estimates of efficacy. The use of adjunctive pharmacotherapy had a statistically significant moderating effect on SD response suggesting that clinical practice should routinely pair these interventions. These findings provide a higher level of evidence supporting the use of SD, especially when used with medication, and should inform future management guidelines for the treatment of BPD.

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.

Relationship between Auditory Evoked Potentials and Circadian Preference in Patients with Major Depressive Episodes

Mood disorders often accompany circadian rhythm abnormalities. The serotonergic system (STS) is related to mood and circadian rhythm. This study aimed to test whether serotonergic neurotransmission, using the loudness dependence of auditory evoked potential (LDAEP), is associated with circadian preference in patients with major depressive disorder (MDD). Depression severity was assessed in 18–65-year-old outpatients (n = 48) using the Beck Depression Inventory scores and Hamilton Depression Rating Scale at baseline. Additionally, various scales, including the Korean version of the Composite Scale of Morningness (K-CSM), Korean version of the Mood Disorder Questionnaire (K-MDQ), and Korean version of the Childhood Trauma Questionnaire (K-CTQ), were used. LDAEP was also measured at baseline. The subjects were divided into three groups according to the circadian preference using total K-CSM scores (morningness (n = 10) vs intermediate (n = 19) vs. eveningness (n = 19)) and two groups according to median based on each K-CSM score, respectively (higher K-CSM (n = 25) vs. lower K-CSM (n = 23)). The bipolarity, suicidality, and age at onset differed among the three groups. Impulsivity, depression severity, suicidality, hopelessness, bipolarity, frequency of emotional abuse, and age at onset differed between the two group divisions. Thus, the STS might serve as the mediator between the circadian system and mood.

Comorbid Bipolar Disorder and Migraine: From Mechanisms to Treatment

Bipolar disorder (BD) is a severe psychiatric disorder characterized by recurrent episodes of manic/hypomanic or depressive symptoms and euthymic periods, with some patients suffering a gradual deterioration of illness and consequent cognitive deficits during the late stage. Migraine is a disease generally without abnormal medical examinations, neurological examinations or laboratory studies, and the diagnosis is made based on the retrospective demonstration of headache features and groupings of disease-associated symptoms. The epidemiology of comorbid BD and migraine is high and it is obligatory to find effective treatments to improve the prognosis. Recent investigations demonstrated that the close relationship between BD and migraine significantly increased the rapid cycling rates of both BD and migraine in patients. Although the detailed mechanism is complex and largely unclear in comorbid BD and migrain, genetic factors, neurotransmitters, altered signaling pathways, disturbances of inflammatory cytokines, and mitochondrial dysfunction are risk factors of BD and migraine. Particularly these two diseases share some overlapping mechanisms according to previous studies. To this end, we call for further investigations of the potential mechanisms, and more efforts are underway to improve the treatment of people with comorbid BD and migraine. In this review, we provide an overview of the potential mechanisms in patients with BD or migraine and we further discuss the treatment strategies for comorbid BD and migraine and it is obligatory to find effective treatments to improve the prognosis. This work will provide insights for us to know more about the mechanisms of comorbid BD and migraine, provides new therapeutic targets for the treatment and give clinicians some guidance for more appropriate and beneficial treatment.