Associations between circadian rhythm instability, appraisal style and mood in bipolar disorder

Zfhx3-mediated genetic ablation of the SCN abolishes light entrainable circadian activity while sparing food anticipatory activity

Circadian rhythms persist in almost all organisms and are crucial for maintaining appropriate timing in physiology and behaviour. Here, we describe a mouse mutant where the central mammalian pacemaker, the suprachiasmatic nucleus (SCN), has been genetically ablated by conditional deletion of the transcription factor Zfhx3 in the developing hypothalamus. Mutants were arrhythmic over the light-dark cycle and in constant darkness. Moreover, rhythms of metabolic parameters were ablated in vivo although molecular oscillations in the liver maintained some rhythmicity. Despite disruptions to SCN cell identity and circuitry, mutants could still anticipate food availability, yet other zeitgebers - including social cues from cage-mates - were ineffective in restoring rhythmicity although activity levels in mutants were altered. This work highlights a critical role for Zfhx3 in the development of a functional SCN, while its genetic ablation further defines the contribution of SCN circuitry in orchestrating physiological and behavioral responses to environmental signals.

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Deletion of Zfhx3 in developing hypothalamus leads to behavioral arrhythmicity

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SCN cell identity is absent while other retinal targets and visual functions remain

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Rhythms in metabolic functions are lost while some molecular rhythms in liver persist

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Conditional mutants can respond to food availability and other environmental cues

Are existing self-ratings of acute manic symptoms in adults reliable and valid?-A systematic review

BACKGROUND

Depression research historically uses both self- and clinician ratings of symptoms with significant and substantial correlations. It is often assumed that manic patients lack insight and cannot accurately report their symptoms. This delayed the development of self-rating scales for mania, but several scales now exist and are used in research. Our objective is to systematically review the literature to identify existing self-ratings of symptoms of (hypo)mania and to evaluate their psychometric properties.

METHODS

PubMed, Web of Knowledge, and Ovid were searched up until June 2018 using the keywords: "(hypo)mania," "self-report," and "mood disorder" to identify papers which included data on the validity and reliability of self-rating scales for (hypo)mania in samples including patients with bipolar disorder.

RESULTS

We identified 55 papers reporting on 16 different self-rating scales claiming to assess (hypo)manic symptoms or states. This included single item scales, but also some with over 40 items. Three of the scales, the Internal State Scale (ISS), Altman Self-Rating Mania Scale (ASRM), and Self-Report Manic Inventory (SRMI), provided data about reliability and/or validity in more than three independent studies. Validity was mostly assessed by comparing group means from individuals in different mood states and sometimes by correlation to clinician ratings of mania.

CONCLUSIONS

ASRM, ISS, and SRMI are promising self-rating tools for (hypo)mania to be used in clinical contexts. Future studies are, however, needed to further validate these measures; for example, their associations between each other and sensitivity to change, especially if they are meant to be outcome measures in studies.

The associations between illness perceptions and social rhythm stability on mood symptoms among patients with bipolar disorder

BACKGROUND

The association between illness perceptions and the effectiveness of patients' illness-management strategies has been supported across a range of medical and psychiatric disorders. Few studies have examined these variables or their association in bipolar disorder (BD). This study examined the main and interactive associations between illness perceptions and one important illness management strategy - social rhythms stability on mood symptom severity in adults with BD.

METHODS

A cross-sectional study with 131 patients with BD in Taiwan was conducted using clinician- and patient-rated mood symptoms, self-reported illness perceptions, and a measure of daily and nightly social rhythms.

RESULTS

Illness perceptions were associated with mood symptom severity, but social rhythms were not. Unfavorable illness perceptions (e.g., beliefs of experiencing more BD symptoms, having stronger emotional responses to the illness) were associated with more severe mood symptoms. Favorable illness perceptions (e.g., beliefs of being able to understand and control the illness) were associated with less severe mood symptoms, with personal control as the strongest correlate of mood symptom severity. Finally, social rhythm stability moderated the relationship between unfavorable illness perceptions and clinician-rated manic symptoms.

LIMITATIONS

The cross-sectional design limits our ability to make causal conclusions. Also, the effects pertain to patients in remission and may not generalize to more severely ill or hospitalized bipolar patients.

CONCLUSIONS

This study indicates that in patients with BD, illness perceptions are associated with symptom severity. Interventions to enhance favorable IPs and reduce unfavorable IPs may improve mood outcomes, particularly when patients have adopted regular social rhythms.

A prospective study of bipolar disorder vulnerability in relation to behavioural activation, behavioural inhibition and dysregulation of the Behavioural Activation System

Background:

The weak regulation, or “dysregulation”, of the Behavioural Activation System (BAS) is implicated in the development and recurrence of bipolar disorder. However, there has been a lack of prospective studies investigating the predictive role of BAS dysregulation in relation to bipolar-vulnerability. Furthermore, no studies have tested the prospective predictive utility of the DYS self-report measure of BAS dysregulation in an analogue sample. The goal of the current study was to redress this gap.

Methods:

Participants (n = 127) completed baseline self-report measures of mood symptoms (Internal States Scale [ISS]), the Hypomanic Personality Scale (HPS), behavioural activation, inhibition and dysregulation of BAS (BIS/BAS and DYS), and at six months, the Mood Disorders Questionnaire (MDQ).

Results:

Linear regression analysis indicated a significant main effect of BAS Dysregulation, and a significant interaction between BIS and BAS Fun Seeking, on prospective MDQ scores whilst controlling for baseline mood symptoms and HPS scores. The interaction effect indicated that the relationship between high BAS Fun Seeking and follow-up MDQ scores was strongest when BIS scores were high, whilst the lowest MDQ scores were observed for a combination of low BAS Fun Seeking and high BIS. However, DYS scores were the stronger predictor of MDQ scores compared to the BAS Fun Seeking and BIS interaction.

Conclusions:

Bipolar-vulnerability is prospectively associated with heightened BAS Dysregulation, as measured by the DYS subscale, similar to prior findings in clinical samples. Further research investigating the longer-term associations between BAS Dysregulation with the development of clinically significant bipolar mood symptoms is required.

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.

Differences in beliefs about mood between people with and without bipolar disorder

Psychological models of bipolar disorder (BD), such as the self-regulation model (SRM; Leventhal, Nerenz, & Steele, 1984), highlight the crucial role of beliefs about mood in relapse vulnerability. To date, no studies have directly compared these beliefs between people with and without BD. Based on the SRM, the current research examined beliefs about mood in people with and without BD and explored the impact of current affect on these beliefs. Fifty euthymic people with a diagnosis of BD and 50 controls were recruited through an online screening study, clinical services, and support organizations. Experience sampling methodology (ESM) was used to assess beliefs (according to the Brief Illness Perceptions Questionnaire; Broadbent, Petrie, Main, & Weinman, 2006) across a typical week of everyday life. Data were analysed using multilevel modelling. Forty-two people with a diagnosis of BD and 50 controls were included in the analyses. Results indicated that the BD group reported less control over mood, a shorter duration of mood, and less understanding of mood and were more likely to report the cause of depressive symptoms as something internal, compared with controls. When controlling for current affect, the BD group also reported more positive consequences, made more internal attributions for hypomanic symptoms, and reported less concern about mood, compared with controls. Findings suggest important differences in beliefs about mood between people with and without BD that are not the result of current affect. These beliefs may be particularly important in understanding underlying vulnerability to future relapse into depression and/or mania.

Evaluation of affective temperament and anxiety-depression levels in fibromyalgia patients: a pilot study

OBJECTIVE

Fibromyalgia (FM) patients have higher rates of depression and anxiety disorders than healthy controls. Affective temperament features are subclinical manifestations of mood disorders. Our aim was to evaluate the affective temperaments of FM patients and investigate their association with depression and anxiety levels and clinical findings.

METHODS

This cross-sectional study included FM patients and healthy controls. The Hospital Anxiety and Depression Scale (HADS) was used to determine patient anxiety and depression levels, and the Temperament Scale of Memphis, Pisa and San Diego, self-administered version was applied to assess affective temperaments in all subjects. Disease severity was assessed in FM patients with the Fibromyalgia Criteria and Severity Scales and the Fibromyalgia Impact Questionnaire (FIQ). Differences between groups were evaluated using Student's t-tests. Correlations among parameters were performed.

RESULTS

This study involved 38 patients with FM (30 female) and 30 healthy controls (25 female). Depressive, anxious and cyclothymic temperaments were significantly higher in FM patients than healthy controls. Statistically significant positive correlations were found between HADS depression score and all temperaments except hyperthymic, as well as between HADS anxiety score and cyclothymic and anxious temperaments. HADS depression and anxiety scores were correlated with symptom severity. We found a higher risk of depression and anxiety among FM patients with higher FIQ scores.

CONCLUSION

This study is the first to evaluate affective temperament features of FM patients. Evaluating temperamental traits in FM patients may help clinicians determine which patients are at risk for depression and anxiety disorders.

Abnormal sleep duration associated with hastened depressive recurrence in bipolar disorder

BACKGROUND

Abnormal sleep duration (ASD, <6 or ≥9h) is common in bipolar disorder (BD), and often persists beyond acute mood episodes. Few longitudinal studies have examined the ASD's impact upon BD illness course. The current study examined the longitudinal impact of ASD upon bipolar depressive recurrence/recovery.

METHODS

Outpatients referred to the Stanford BD Clinic during 2000-2011 were assessed with the Systematic Treatment Enhancement Program for BD (STEP-BD) Affective Disorders Evaluation at baseline, and with the Clinical Monitoring Form at monthly follow-ups for up to two years of naturalistic treatment. Prevalence and clinical correlates of ASD in 93 recovered (euthymic ≥8 weeks) and 153 depressed BD patients were assessed. Kaplan-Meier analyses (Log-Rank tests) assessed relationships between baseline ASD and longitudinal depressive severity, with Cox Proportional Hazard analyses assessing potential mediators.

RESULTS

ASD was only half as common among recovered versus depressed BD outpatients, but was significantly associated with hastened depressive recurrence (Log-Rank p=0.007), mediated by lifetime anxiety disorder and attenuated by lifetime history of psychosis, and had only a non-significant tendency towards association with delayed depressive recovery (Log-Rank p=0.07). In both recovered and depressed BD outpatients, baseline ASD did not have significant association with any baseline BD illness characteristic.

LIMITATIONS

Self-reported sleep duration. Limited generalizability beyond our predominately white, female, educated, insured American BD specialty clinic sample.

CONCLUSIONS

Baseline ASD among recovered BD patients may be a risk marker for hastened depressive recurrence, suggesting it could be an important therapeutic target between mood episodes.

Mood disorders and biological rhythms in young adults: A large population-based study

BACKGROUND

It is known that sleep disturbance has been considered a trait-marker of mood disorders. However, the role of disruptions in biological rhythms, such as eating, activity, and social patterns, needs to be better understood.

AIM

To assess the differences in biological rhythms in subjects with bipolar disorder, major depressive disorder, and healthy controls. We also tested the association between disruptions of biological rhythms and circadian preferences.

METHODS

A cross-sectional, population-based study with a representative sample of 1023 young adults. Bipolar disorder and depression were diagnosed using The Mini International Neuropsychiatric Interview - PLUS and DSM Structured Clinical Interview. Self-reported biological rhythms and circadian preference were assessed using the Biological Rhythm Interview of Assessment in Neuropsychiatry (BRIAN).

RESULTS

Bipolar disorders and depression subjects presented higher rates of disruption in biological rhythms when compared to healthy controls even after adjusting for sex, socioeconomic status, alcohol, tobacco, illicit drug use, anxiety disorder and psychotropic medication use. Euthymic subjects showed higher biological rhythm disruption when compared to controls. Higher disruption in biological rhythms was observed in subjects with evening preferences.

CONCLUSION

Higher disruption in biological rhythms occurs in individuals with depression and bipolar disorder even on periods of euthymia.