Lifetime experiences of hypomanic symptoms are associated with delayed and irregular sleep-wake cycle and seasonality in non-clinical adult samples

The importance of sleep regularity: a consensus statement of the National Sleep Foundation sleep timing and variability panel

OBJECTIVE

To develop and present consensus findings of the National Sleep Foundation sleep timing and variability panel regarding the impact of sleep timing variability on health and performance.

METHODS

The National Sleep Foundation assembled a panel of sleep and circadian experts to evaluate the scientific evidence and conduct a formal consensus and voting procedure. A systematic literature review was conducted using the NIH National Library of Medicine PubMed database, and panelists voted on the appropriateness of 3 questions using a modified Delphi RAND/UCLA Appropriateness Method with 2 rounds of voting.

RESULTS

The literature search and panel review identified 63 full text publications to inform consensus voting. Panelists achieved consensus on each question: (1) is daily regularity in sleep timing important for (a) health or (b) performance? and (2) when sleep is of insufficient duration during the week (or work days), is catch-up sleep on weekends (or non-work days) important for health? Based on the evidence currently available, panelists agreed to an affirmative response to all 3 questions.

CONCLUSIONS

Consistency of sleep onset and offset timing is important for health, safety, and performance. Nonetheless, when insufficient sleep is obtained during the week/work days, weekend/non-work day catch-up sleep may be beneficial.

[Chronobiological aspects of bipolar disorder]

BACKGROUND

Numerous symptoms of bipolar disorder are regulated by the circadian rhythm. Because of this association it is assumed that disruption of the circadian rhythm may be part of the pathomechanism of bipolar disorder.

OBJECTIVES

A comparison and subsequent critical discussion of the current data situation on chronobiological aspects of bipolar disorder are presented.

METHODS

A narrative literature search was carried out and the main findings are presented in a summarized form.

RESULTS

There are a large number of animal and human studies investigating the connection between disorders of the circadian rhythm and bipolar disorder. Especially chronotype, the environmental factor light and sleep disorders seem to be associated with the development of bipolar disorder.

CONCLUSIONS

The neurobiology of bipolar disorder shows numerous chronobiological aspects. There is evidence for a direct connection of disruption of the circadian rhythm and development and progression of bipolar disorder; however, at present there is no proof for the specificity of these findings for bipolar disorder. Future studies should consolidate the evidence on the impact of disorders of the circadian rhythm on the pathomechanism of bipolar disorder.

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.

Clinical Correlates of False Positive Assignment in Bipolar Screening Measures Across Psychiatric Diagnoses among Patients without Bipolar Disorder

OBJECTIVE

In this study, we aimed to determine clinical correlates of false positive assignment (FPA) on commonly used bipolar screening questionnaires.

METHODS

A retrospective chart review was conducted to a total of 3885 psychiatric outpatients. After excluding patients who have bipolar spectrum illnesses, patients who were assigned as having hypomania on the mood disorder questionnaire (MDQ) or the hypomania checklist-32 (HCL-32) were identified as patients who had FPA. Psychiatric diagnoses and severity of emotional symptoms were compared between patients with and without FPA.

RESULTS

Patients with FPA on the MDQ showed significant associations with presence of major depressive disorder, generalized anxiety disorder, and alcohol-use disorder, while patients with FPA on the HCL-32 showed associations with presence of panic disorder and agoraphobia. FPA on the MDQ was also associated with greater emotional symptoms and lifetime history of suicide attempts. Logistic regression analysis showed that male sex, younger age, presence of alcohol-use disorder, and severity of depression and obsessive-compulsive symptoms were significantly associated with FPA on the MDQ.

CONCLUSION

The FPA for the MDQ was associated with clinical factors linked to trait impulsivity, and the FPA for both the MDQ and the HCL-32 could be related to increased anxiety.

Psychopathologic structure of bipolar disorders: exploring dimensional phenotypes, their relationships, and their associations with bipolar I and II disorders

BACKGROUND

Given its diverse disease courses and symptom presentations, multiple phenotype dimensions with different biological underpinnings are expected with bipolar disorders (BPs). In this study, we aimed to identify lifetime BP psychopathology dimensions. We also explored the differing associations with bipolar I (BP-I) and bipolar II (BP-II) disorders.

METHODS

We included a total of 307 subjects with BPs in the analysis. For the factor analysis, we chose six variables related to clinical courses, 29 indicators covering lifetime symptoms of mood episodes, and 6 specific comorbid conditions. To determine the relationships among the identified phenotypic dimensions and their effects on differentiating BP subtypes, we applied structural equation modeling.

RESULTS

We selected a six-factor solution through scree plot, Velicer's minimum average partial test, and face validity evaluations; the six factors were cyclicity, depression, atypical vegetative symptoms, elation, psychotic/irritable mania, and comorbidity. In the path analysis, five factors excluding atypical vegetative symptoms were associated with one another. Cyclicity, depression, and comorbidity had positive associations, and they correlated negatively with psychotic/irritable mania; elation showed positive correlations with cyclicity and psychotic/irritable mania. Depression, cyclicity, and comorbidity were stronger in BP-II than in BP-I, and they contributed significantly to the distinction between the two disorders.

CONCLUSIONS

We identified six phenotype dimensions; in addition to symptom features of manic and depressive episodes, various comorbidities and high cyclicity constructed separate dimensions. Except for atypical vegetative symptoms, all factors showed a complex interdependency and played roles in discriminating BP-II from BP-I.

Factorial structure and familial aggregation of the Hypomania Checklist-32 (HCL-32): Results of the NIMH Family Study of Affective Spectrum Disorders

BACKGROUND

There is substantial evidence that bipolar disorder (BD) manifests on a spectrum rather than as a categorical condition. Detection of people with subthreshold manifestations of BD is therefore important. The Hypomania Checklist-32 (HCL-32) was developed as a tool to identify such people.

PURPOSE

The aims of this paper were to: (1) investigate the factor structure of HCL-32; (2) determine whether the HCL-32 can discriminate between mood disorder subtypes; and (3) assess the familial aggregation and cross-aggregation of hypomanic symptoms assessed on the HCL with BD.

PROCEDURES

Ninety-six probands recruited from the community and 154 of their adult first-degree relatives completed the HCL-32. Diagnosis was based on semi-structured interviews and family history reports. Explanatory factor analysis and mixed effects linear regression models were used.

FINDINGS

A four-factor ("Activity/Increased energy," "Distractibility/Irritability", "Novelty seeking/Disinhibition, "Substance use") solution fit the HCL-32, explaining 11.1% of the total variance. The Distractibility/Irritability score was elevated among those with BP-I and BP-II, compared to those with depression and no mood disorders. Higher HCL-32 scores were associated with increased risk of BD-I (OR = 1.22, 95%CI 1.14-1.30). The "Distractibility/Irritability" score was transmitted within families (β = 0.15, p = 0.040). However, there was no familial cross-aggregation between mood disorders and the 4 HCL factors.

CONCLUSIONS

Our findings suggest that the HCL-32 discriminates the mood disorder subtypes, is familial and may provide a dimensional index of propensity to BD. Future studies should explore the heritability of symptoms, rather than focusing on diagnoses.

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.

"Always Look on the Bright Side of Life!" - Higher Hypomania Scores Are Associated with Higher Mental Toughness, Increased Physical Activity, and Lower Symptoms of Depression and Lower Sleep Complaints

Background: In the present study, we explored the associations between hypomania, symptoms of depression, sleep complaints, physical activity and mental toughness. The latter construct has gained interest for its association with a broad variety of favorable behavior in both clinical and non-clinical samples.

Subjects and Methods: The non-clinical sample consisted of 206 young adults (M = 21.3 years; age range: 18–24 years; 57.3% males). They completed questionnaires covering hypomania, mental toughness, symptoms of depression, physical activity, and sleep quality.

Results: Higher hypomania scores were associated with higher mental toughness, increased physical activity, lower symptoms of depression and lower sleep complaints. No gender differences were observed. Higher hypomania scores were predicted by higher scores of mental toughness subscales of control and challenge, and physical activity.

Conclusion: The pattern of results suggests that among a non-clinical sample of young adults, self-rated hypomania scores were associated with higher scores on mental toughness and physical activity, along with lower depression and sleep complaints. The pattern of results further suggests that hypomania traits are associated with a broad range of favorable psychological, behavioral and sleep-related traits, at least among a non-clinical sample of young adults.

Investigation of the clinical utility of the hypomania checklist 32 (HCL-32) for the screening of bipolar disorders in the non-clinical adult population

BACKGROUND

The hypomania checklist-32 (HCL-32) is a widely used questionnaire developed for identifying hypomanic components in patients with a depressive episode. Measuring and screening previous hypomanic symptoms in individuals without any definite history of depressive episode would also be needed for early detection of bipolar disorders (BDs). This study aimed at testing the clinical utility of the HCL-32 for screening of BDs in the non-clinical population.

METHODS

Lifetime history of hypomanic symptoms was evaluated by using the HCL-32 in 220 patients with BDs and 313 non-clinical individuals. Sensitivity, specificity, and the area under the curve (AUC) of the Receiver Operating Characteristic (ROC) were evaluated for assessing the discriminatory power of the scale and its two sub-domains in screening BDs.

RESULTS

The mean HCL-32 total score was significantly higher in the Bipolar II disorder group compared to the non-clinical group (P < 0.001). Most of the items (10/12) of the irritable/risk-taking factor showed higher positive responses in patient groups. Items of active/elated factor showed mixed results. The HCL-32 total score and the active/elated factor score were not adequate for both BDs and its subgroups with AUC values of less than 0.7. The irritable/risk-taking factor score showed higher discrimination power, i.e. AUC for BDs, Bipolar I disorder, and Bipolar II disorder was 0.71, 0.67, and 0.75, respectively.

CONCLUSIONS

The HCL-32 could not adequately distinguish BD patients from the non-clinical adult population. However, the current study identified items of irritable/risk-taking factor of the scale that could be useful in screening BDs in the general population.

The association between biological rhythms, depression, and functioning in bipolar disorder: a large multi-center study

OBJECTIVE

We examined the relationship between biological rhythms and severity of depressive symptoms in subjects with bipolar disorder and the effects of biological rhythms alterations on functional impairment.

METHOD

Bipolar patients (n = 260) and healthy controls (n = 191) were recruited from mood disorders programs in three sites (Spain, Brazil, and Canada). Parameters of biological rhythms were measured using the Biological Rhythms Assessment in Neuropsychiatry (BRIAN), an interviewer administered questionnaire that assesses disruptions in sleep, eating patterns, social rhythms, and general activity.

RESULTS

Multivariate analyses of covariance showed significant intergroup differences after controlling for potential confounders (Pillai's F = 49.367; df = 2, P < 0.001). Depressed patients had the greatest biological rhythms disturbance, followed by patients with subsyndromal symptoms, euthymic patients, and healthy controls. Biological rhythms and HAMD scores were independent predictors of poor functioning (F = 12.841, df = 6, P < 0.001, R²  = 0.443).

CONCLUSION

Our study shows a dose-dependent association between the severity of depressive symptoms and degree of biological rhythms disturbance. Biological rhythms disturbance was also an independent predictor of functional impairment. Although the directionality of this relationship remains unknown, our results suggest that stability of biological rhythms should be an important target of acute and long-term management of bipolar disorder and may aid in the improvement of functioning.

Integrated neurobiology of bipolar disorder

From a neurobiological perspective there is no such thing as bipolar disorder. Rather, it is almost certainly the case that many somewhat similar, but subtly different, pathological conditions produce a disease state that we currently diagnose as bipolarity. This heterogeneity - reflected in the lack of synergy between our current diagnostic schema and our rapidly advancing scientific understanding of the condition - limits attempts to articulate an integrated perspective on bipolar disorder. However, despite these challenges, scientific findings in recent years are beginning to offer a provisional "unified field theory" of the disease. This theory sees bipolar disorder as a suite of related neurodevelopmental conditions with interconnected functional abnormalities that often appear early in life and worsen over time. In addition to accelerated loss of volume in brain areas known to be essential for mood regulation and cognitive function, consistent findings have emerged at a cellular level, providing evidence that bipolar disorder is reliably associated with dysregulation of glial-neuronal interactions. Among these glial elements are microglia - the brain's primary immune elements, which appear to be overactive in the context of bipolarity. Multiple studies now indicate that inflammation is also increased in the periphery of the body in both the depressive and manic phases of the illness, with at least some return to normality in the euthymic state. These findings are consistent with changes in the hypothalamic-pituitary-adrenal axis, which are known to drive inflammatory activation. In summary, the very fact that no single gene, pathway, or brain abnormality is likely to ever account for the condition is itself an extremely important first step in better articulating an integrated perspective on both its ontological status and pathogenesis. Whether this perspective will translate into the discovery of innumerable more homogeneous forms of bipolarity is one of the great questions facing the field and one that is likely to have profound treatment implications, given that fact that such a discovery would greatly increase our ability to individualize - and by extension, enhance - treatment.