Significant sleep disturbances in euthymic bipolar patients

Striatal Dopamine Transporter Availability is Associated with Sleep Disturbance among Patients with Bipolar I Disorder: A Single-photon Emission Computed Tomography Study Using [99mTc] TRODAT-1

OBJECTIVE

Bipolar disorder (BD) is characterized by the poor sleep quality. Whether the striatal dopamine transporter (DAT) availability is related to sleep quality among patients with BD is unclear.

METHODS

Fifty-three euthymic patients with BD (24 BD-I and 29 BD-II) and sixty-eight healthy controls were enrolled. The Chinese Version of the Pittsburgh Sleep Quality Index (PSQI) was used, and the availability of DAT was assessed by single-photon emission computed tomography (SPECT) using [^99mTc] TRODAT-1.

RESULTS

The sleep disturbance component of the PSQI was significantly associated with the level of DAT availability among patients with BD.

CONCLUSION

The striatal dopaminergic activity that contributes to resilience to adversity was associated with sleep pattern among patients with BD.

The Clinical Science of Euthymia: A Conceptual Map

Euthymia is a trans-diagnostic construct characterized by lack of mood disturbances; presence of positive affect; balance of psychological well-being dimensions, flexibility, consistency, and resistance to stress. The aim of this critical review is to draw a conceptual map of euthymia. Relationships with other constructs, continuum between euthymia and dysthymia with discomfort as an intermediate area, associations with lifestyle, clinimetric assessment, role of psychotherapeutic interventions, establishment of therapeutic targets, and neurobiological mechanisms are discussed. The model is based on the bipolar nature of well-being dimensions. Euthymia means using allostasis optimally and maintaining a healthy balance that promotes positive aspects of brain and body health through health-promoting behaviors. It may provide a framework for a renewed definition of recovery, for measuring treatment outcome and for targeting interventions, including the sequential administration of therapeutic components. Clinical assessment requires a clinimetric approach encompassing a broad range of aspects, such as allostatic load and lifestyle behaviors, all interacting with each other and contributing to the euthymia/dysthymia balance. Clinimetric indices for assessing euthymia (the Clinical Interview for Euthymia and the Euthymia Scale) and related constructs (the Clinical Interview for Dysthymia and the Semi-Structured Interview for the Diagnostic Criteria for Psychosomatic Research) are presented here. Well-Being Therapy, a psychotherapeutic strategy specifically aimed at pursuing euthymia, relies on self-observation of well-being episodes using a structured diary as a distinct therapeutic ingredient. The clinical science of euthymia may unravel innovative approaches to assessment and treatment of psychiatric and medical disorders, according to a unitary conceptual framework.

The significance of sleep quality in euthymic bipolar patients from Nigeria

Background

Bipolar disorder is highly under-researched in Africa. Existing studies show that racial/ethnic disparities exist for sleep quality. Poor sleep quality in bipolar disorder causes significant morbidity and mortality even during periods of euthymia.

Aim

This study aimed to assess sleep quality and its correlates amongst euthymic patients with bipolar I disorder from Nigeria.

Setting

The study was carried out in a teaching hospital, and state hospital, in Ibadan, Nigeria.

Method

This cross-sectional study was conducted amongst 76 euthymic bipolar patients aged between 18 and 60 years, meeting the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) diagnostic criteria for bipolar disorder. Euthymia was defined as having a score of ≤ 5 on the Young Mania Rating Scale and < 8 on the Hamilton Depression Rating Scale. Sleep quality was assessed with the Pittsburgh Sleep Quality Index (PSQI).

Results

A total of 37 (48.7%) participants had poor quality sleep. Sleep quality was associated with marital status (p = 0.013) and suicide plan (p = 0.047). Participants with good sleep quality had higher total sleep duration, lower time to fall asleep (sleep latency), better subjective quality of sleep, were less likely to use sleep medications and had less daytime dysfunction than participants with poor sleep quality. All p-values were < 0.05. Subjective quality of sleep, ongoing use of sleep medication, daytime dysfunction were independently associated with poor sleep quality.

Conclusion

Poor sleep quality frequently persists during euthymic periods in patients with bipolar disorder. The correlates identified can be targeted for intervention during treatment.

Chronobiology Revisited in Psychiatric Disorders: From a Translational Perspective

OBJECTIVE

Several lines of evidence support a relationship between circadian rhythms disruption in the onset, course, and maintenance of mental disorders. Despite the study of circadian phenotypes promising a decent understanding of the pathophysiologic or etiologic mechanisms of psychiatric entities, several questions still need to be addressed. In this review, we aimed to synthesize the literature investigating chronobiologic theories and their associations with psychiatric entities.

METHODS

The Medline, Embase, PsycInfo, and Scopus databases were comprehensively and systematically searched and articles published between January 1990 and October 2019 were reviewed. Different combinations of the relevant keywords were polled. We first introduced molecular elements and mechanisms of the circadian system to promote a better understanding of the chronobiologic implications of mental disorders. Then, we comprehensively and systematically reviewed circadian system studies in mood disorders, schizophrenia, and anxiety disorders.

RESULTS

Although subject characteristics and study designs vary across studies, current research has demonstrated that circadian pathologies, including genetic and neurohumoral alterations, represent the neural substrates of the pathophysiology of many psychiatric disorders. Impaired HPA-axis function-related glucocorticoid rhythm and disrupted melatonin homeostasis have been prominently demonstrated in schizophrenia and other psychotic disorders, while alterations of molecular expressions of circadian rhythm genes including CLOCK, PER, and CRY have been reported to be involved in the pathogenesis of mood disorders.

CONCLUSION

Further translational work is needed to identify the causal relationship between circadian physiology abnormalities and mental disorders and related psychopathology, and to develop sound pharmacologic interventions.

Sleep quality and emotional reactivity cluster in bipolar disorders and impact on functioning

Objective:

Bipolar disorders (BD) are characterized by sleep disturbances and emotional dysregulation both during acute episodes and remission periods. We hypothesized that sleep quality (SQ) and emotional reactivity (ER) defined clusters of patients with no or abnormal SQ and ER and we studied the association with functioning.

Method:

We performed a bi-dimensional cluster analysis using SQ and ER measures in a sample of 533 outpatients patients with BD (in remission or with subsyndromal mood symptoms). Clusters were compared for mood symptoms, sleep profile and functioning.

Results:

We identified three clusters of patients: C1 (normal ER and SQ, 54%), C2 (hypo-ER and low SQ, 22%) and C3 (hyper-ER and low SQ, 24%). C1 was characterized by minimal mood symptoms, better sleep profile and higher functioning than other clusters. Although highly different for ER, C2 and C3 had similar levels of subsyndromal mood symptoms as assessed using classical mood scales. When exploring sleep domains, C2 showed poor sleep efficiency and a trend for longer sleep latency as compared to C3. Interestingly, alterations in functioning were similar in C2 and C3, with no difference in any of the sub-domains.

Conclusion:

Abnormalities in ER and SQ delineated three clusters of patients with BD and significantly impacted on functioning.

Role of biological rhythm dysfunction in the development and management of bipolar disorders: a review

Disturbance of biological rhythms contributes to the onset of bipolar disorders and is an important clinical feature of the condition. To further explore the role of biological rhythms in bipolar disorders, 95 English articles published between 1968 and 2019 were retrieved from the PubMed database and analysed. We herein review the outcomes of studies on biological rhythm disturbance in bipolar disorders, including the epidemiology, aetiology, clinical features (eg, sleep, feeding and eating disorders) and treatment of the condition evaluated by patients’ self-report and biological indicators such as melatonin. Our report supports the characterisation of biological rhythm disturbance as a significant clinical feature affecting the onset and development of bipolar disorders and reviews classical and novel treatments, such as chronotherapy, that can be applied in the clinical practice. Our analysis indicates that a more comprehensive study of the pathophysiology, clinical phenomenology and treatment of biological rhythm disturbance is required.

The pursuit of euthymia

Psychiatrists often consider the positive characteristics displayed by a patient in their clinical judgment, yet current assessment and treatment strategies are shifted on the side of psychological dysfunction. Euthymia is a transdiagnostic construct referring to the presence of positive affects and psychological well-being, i.e., balance and integration of psychic forces (flexibility), a unifying outlook on life which guides actions and feelings for shaping future accordingly (consistency), and resistance to stress (resilience and tolerance to anxiety or frustration). There is increasing evidence that the evaluation of euthymia and its components has major clinical implications. Specific instruments (clinical interviews and questionnaires) may be included in a clinimetric assessment strategy encompassing macro-analysis and staging. The pursuit of euthymia cannot be conceived as a therapeutic intervention for specific mental disorders, but as a transdiagnostic strategy to be incorporated in an individualized therapeutic plan. A number of psychotherapeutic techniques aiming to enhance positive affects and psychological well-being (such as well-being therapy, mindfulness-based cognitive therapy, and acceptance and commitment therapy) have been developed and validated in randomized controlled clinical trials. The findings indicate that flourishing and resilience can be promoted by specific interventions leading to a positive evaluation of one's self, a sense of continuing growth and development, the belief that life is purposeful and meaningful, satisfaction with one's relations with others, the capacity to manage effectively one's life, and a sense of self-determination.

Sleep Disturbance in Bipolar Disorder: Neuroglia and Circadian Rhythms

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

Decreased need for sleep as an endophenotype of bipolar disorder: an actigraphy study

Reports of subjective sleep impairments have been replicated in adults with bipolar disorder (BD), young BD patients, and even children of parents with BD. Furthermore, circadian rhythm alterations are a core feature of BD. Despite the impairment in circadian rhythms and altered sleep included in various heuristic developmental models of BD, thus far, biomarkers have not been sufficiently objectively validated. Thus, here, we assessed the rest-activity circadian rhythmicity and sleep macrostructure using actigraphy in a sample of unaffected child and adolescent offspring of bipolar parents (BO; n = 43; 21 females; 11.0 ± 3.2 years) and controls (n = 42; 17 females; 11.1 ± 3.4 years) comparable in sex (p = .4) and age (p = .7). All participants wore a MotionWatch 8 (Camntech, Cambridge, UK) actigraph on their nondominant wrist for ≥ 14 days and completed sleep diaries. Psychopathology was assessed by the Kiddie Schedule for Affective Disorders and Schizophrenia and by subjective scales. The main areas of interest were rest-activity circadian rhythmicity, chronotype and sleep macrostructure. Subgroup analyses (child and adolescent subgroups) were conducted to identify physiological differences in sleep between these age groups. The BO and controls did not differ in the presence of current mood (p = .5) and anxiety (p = .6) disorders. The BO had shorter sleep time on free days (p = .007; effect size, Cohen´s d = 0.56), lower sleep efficiency on free days (p = .01; d = 0.47), lower prolongation of time in bed on free days (p = .046; d = 0.41), and lower social jet lag (p = .04; d = 0.5) than the controls. A longer sleep time on school days (p < .001; d = 0.21), lower prolongation of sleep time between school and free days (p = .008; d = 0.74), and larger difference in sleep onset latency between school days and free days (p = .009; d = 0.52) were observed in the adolescent BO than in the controls. The child BO had poorer sleep quality on free days than the controls (p = .02; d = 0.96). In all cases, the results remained significant after controlling for subthreshold mood and anxiety symptoms. The BO had less variable rest-activity rhythm than controls (p = .04; d = 0.32). No other significant differences between the BO and controls were observed in the rest-activity circadian rhythmicity and chronotype. The results showed decreased physiological catch-up sleep on free days in the BO, which may indicate a decreased need for sleep in this population. Thus, the decreased need for sleep observed in the unaffected BO may represent an endophenotype of BD.

The impact of clinical comorbidities and residual depressive symptoms in sleep quality in euthymic/interepisodic bipolar subjects

Sleep disturbances are feasibly linked with poorer outcome in BD. This study aims to cross-sectionally investigate clinical factors associated with sleep disruption in euthymic BD patients. We assessed sleep quality in a sample of 209 euthymic BD patients with the Pittsburgh Sleep Quality Index. After multiple logistic regression analysis controlling for several confounding factors, the variables number of clinical diseases and Hamilton global score remained significant and independently associated with poor sleep quality. Our results suggest that euthymic BD patients presenting poor sleep quality are more likely to have clinical comorbidities and manifest subsyndromal depressive symptomatology.

Circadian rhythm in bipolar disorder: A review of the literature

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

Is there any relationship between quality of life and polysomnographically detected sleep parameters/disorders in stable myasthenia gravis?

It is known that quality of life in myasthenia gravis is positively correlated with subjective sleep quality, still no data is available regarding the relationship between QOL and polysomnographically detected sleep parameters and disorders. In this study, we tried to highlighten this relationship, by performing polysomnography. Sleep-related complaints were evaluated in face-to-face interviews with 19 clinically stable MG patients and 26 healthy controls. During the interviews questionnaires assessing sleep quality, excessive daytime sleepiness, fatigue, depression, anxiety, and Turkish version of the MG-QOL 15-item scale [(MG-QOL15(T)] were administered and then an overnight polysomnography was performed. Sleep disorders, especially obstructive sleep apnea and fatigue were higher, whereas subjective sleep duration was significantly lower, in patients than controls. Excessive daytime sleepiness and poor sleep quality were not different between patients and controls. Other than percentage of sleep stage III, which was negatively correlated with MG-QOL15(T) scores, neither other sleep parameters nor sleep disorders were correlated with MG-QOL15(T) scores. MG composite, subjective sleep duration, fatigue severity and Hamilton depression rating scale scores were found to be positively correlated with MG-QOL15(T) scores. It was shown that decreasing disease severity and enhancing psychological well-being will improve patients' quality of life. We recommend that our findings should be repeated in a large prospective cohort of MG patients.

Assessment of sleep quality in bipolar euthymic patients

OBJECTIVE

Sleep quality is affected in bipolar disorder even in euthymic episodes. The aim of this study was to assess sleep quality in bipolar euthymic patients, determine related clinical characteristics and evaluate its effects on functionality.

METHODS

A total of 122 outpatients were included. Scales were used to confirm that patients were euthymic. Mini Mental Test was performed to exclude patients with a diagnosis of dementia. A data form for socio-demographic features and clinical characteristics of bipolar disorder have been completed. SCID-I and SCID II were used. The general features of sleep were investigated by General Sleep Questionnaire. All patients completed Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale and Bipolar Disorder Functioning Questionnaire.

RESULTS

56.5% of our sample had poor sleep quality. Patients with poor sleep had a longer time to fall asleep and more frequent waking after sleep onset. Caffeine use and smoking, history of suicide attempts, seasonality, comorbidity of lifetime anxiety, somatoform and impulse control disorders, using antidepressant medication and administration of electroconvulsive therapy were significantly higher; emotional and intellectual functioning, household relations, taking initiative, self-sufficiency and total functionality were lower in bipolar patients with poor sleep quality (p<0.05). The strongest predictor of sleep quality problem was seasonality, recording an odds ratio of 3.91.

CONCLUSIONS

Sleep quality is closely related with clinical features of bipolar disorder. Sleep quality is affected negatively in euthymic episodes of bipolar disorder and poor sleep quality cause loss in functionality. Assessment of sleep disturbances routinely in psychiatric interviews and dealing with sleep problems regardless mood episodes may improve sleep quality, thereby functionality and quality of life.

Genetic Association of the PERIOD3 (Per3) Clock Gene with Bipolar Disorder

OBJECTIVE

Circadian rhythms have been linked to psychiatric disorders such as Depression and Bipolar Disorder (BD). Given previous evidences of sleep/circadian disturbances as well as the genetic susceptibility for BD, we decided to investigate the possible link between the PERIOD3 (Per3) circadian gene and BD.

METHODS

This is a genetic association case (BD) vs. control study of the Per3 gene. We further subdivided our BD sample into "good sleepers" (PSQI ≤5) and "poor sleepers" (PSQI>5) according to the Pittsburgh Sleep Quality Index (PSQI) global score, and then we assessed genetic association of the Per3 gene with sleep quality in the BD group.

RESULTS

There were 209 cases and 213 controls in our sample. The GT genotype of the SNP rs707467 significantly associated with BD (χ²=8.80; p-value=0.01; adjusted residual=±2.6). We also found significant association of the SNP rs10462020 allele T with BD (χ²=5.81; p-value=0.01) as well as the genotype TT (χ²= 6.01; p-value=0.04; adjusted residual=±2.4).

CONCLUSION

In this study we demonstrated evidences of genetic association between the Per3 gene and BD. The results of association between the Per3 gene and BD in our sample may bring additional evidence to the former findings of association between the Per3 gene and BD.

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.

An actigraphy study investigating sleep in bipolar I patients, unaffected siblings and controls

OBJECTIVES

Disturbances in sleep and waking patterns are highly prevalent during mood episodes in bipolar disorder. The question remains whether these disturbances persist during phases of euthymia and whether they are heritable traits of bipolar disorder. The current study investigates objective sleep measures in a large sample of bipolar I patients, non-affected siblings and controls.

METHODS

A total of 107 bipolar disorder I patients, 74 non-affected siblings, and 80 controls were included. Sleep was measured with actigraphy over the course of 14 days. Seven sleep parameters were analyzed for group differences and their relationship with age at onset, number of episodes and psychotic symptoms using linear mixed model analysis to account for family dependencies.

RESULTS

Patients had a longer sleep duration and later time of sleep offset compared to the non-affected siblings but these differences were entirely attributable to differences in mood symptoms. We found no difference between patients and controls or siblings and controls when the analyses were restricted to euthymic patients. None of the bipolar illness characteristics were associated with sleep.

LIMITATIONS

Medication use was not taken into account which may have influenced our findings and controls were younger compared to non-affected siblings.

CONCLUSIONS

In the largest study to date, our findings suggest that recovered bipolar I patients and their siblings do not experience clinically significant sleep disturbances. Sleep disturbances are primarily a reflection of current mood state, but are unrelated to the course of the disorder.

An examination of sleep quality in veterans with a dual diagnosis of PTSD and severe mental illness

Poor sleep quality is one of the most frequently reported symptoms by veterans with Posttraumatic Stress Disorder (PTSD) and by veterans with severe mental illness (SMI; i.e., schizophrenia spectrum disorders, bipolar disorder, major depression with or without psychotic features). However, little is known about the compounding effects of co-occurring PTSD/SMI on sleep quality in this population. Given the high rates of comorbidity and poor functional outcomes associated with sleep dysfunction, there is a need to better understand patterns of poor sleep quality in this population. The present study provides a description of sleep quality in veterans with a dual diagnosis of PTSD/SMI relative to veterans with PTSD only. Results indicated that, despite similar reports of PTSD symptom severity between the groups, veterans with PTSD/SMI reported higher levels of poor sleep quality than veterans only diagnosed with PTSD. Specifically, veterans with PTSD/SMI reported significantly greater difficulties with sleep onset and overall more sleep disturbance than their non-SMI counterparts. Implications of the findings are discussed within the context of an existing model of insomnia and suggest that more comprehensive sleep assessment and the provision of targeted sleep interventions may be helpful for those with a dual diagnosis of PTSD/SMI.

Effect of early trauma on the sleep quality of euthymic bipolar patients

OBJECTIVE

Poor quality of sleep is frequent in euthymic bipolar patients and conveys worse clinical outcomes. We investigated the features of euthymic bipolar patients associated with poor sleep quality, with a focus on the effect of childhood trauma.

METHOD

493 euthymic patients with DSM-IV-defined bipolar disorders were recruited in FondaMental Advanced Centers of Expertize for Bipolar Disorders (FACE-BD) between 2009 and 2014. Clinical variables were recorded. Subjective sleep quality and history of childhood trauma were respectively measured by the Pittsburgh Sleep Quality Index (PSQI) and the Childhood Trauma Questionnaire (CTQ).

RESULTS

Poor sleepers were older, less professionally active, had significantly higher anxiety levels, took more anxiolytic drugs and did endorse more suicide attempts and suicidal ideas than good sleepers after adjusting for anxiety levels and age. Emotional abuse was associated with poor sleep quality after adjustment for BMI, age, professional activity, and bipolar disorders (BD) type (OR=1.83; 95% CI [1.30; 3.10]; p=0.02). However, this association was lost after adjustment for anxiety levels, anxiolytic treatment and suicide ideation/attempts.

LIMITATIONS

The main limitation was the type of sleep assessment, which only measured the subjective part of sleep complaints.

CONCLUSION

A history of emotional abuse might underlie sleep problems in many bipolar patients but anxiety seems to act as a confounding factor in this relationship. New studies are needed to elucidate the role of childhood maltreatment on poor sleep among bipolar patients.

Sleep problems in bipolar disorders: more than just insomnia

OBJECTIVE

Sleep problems in bipolar disorder (BD) are common, but reported rates vary from 10% to 80%, depending on definitions, methodologies and management of potential confounding factors. This multicenter study seeks to address these issues and also compares BD cases with Hypersomnia as well as the more commonly investigated Insomnia and No Sleep Problem groups.

METHOD

A cross-sectional comparison of sleep profiles in 563 BD I and II individuals who participated in a structured assessment of demographic, clinical, illness history and treatment variables.

RESULTS

Over 40% cases met criteria for Insomnia and 29% for Hypersomnia. In univariate analysis, Insomnia was associated with BD II depression whilst Hypersomnia was associated with BD I depression or euthymia. After controlling for confounders and covariates, it was demonstrated that Hypersomnia cases were significantly more likely to be younger, have BD I and be prescribed antidepressants whilst Insomnia cases had longer illness durations and were more likely to be prescribed benzodiazepines and hypnotics.

CONCLUSION

Whilst Insomnia symptoms are common in BD, Hypersomnia is a significant, frequently underexplored problem. Detailed analyses of large representative clinical samples are critical to extending our knowledge of differences between subgroups defined by sleep profile.

Biological rhythms are independently associated with quality of life in bipolar disorder

Background

Evidence suggests that patients with bipolar disorder (BD) experience biological rhythm disturbances; however, no studies have examined the impact of this disruption on quality of life (QOL). The aim of this study is to investigate the influence of biological rhythm, depressive symptoms, sleep quality, and sleep medication use on QOL in BD.

Methods

Eighty BD subjects (44 depressed and 36 euthymic) completed questionnaires assessing QOL (WHOQOL-BREF), biological rhythm disruption (BRIAN), depressive symptoms (MADRS), and sleep quality (PSQI). The impact of biological rhythm disturbance, depressive symptoms severity, sleep quality, and sleep medication use on QOL was determined with multiple regression analyses.

Results

BRIAN (β = −0.31, t = −2.73, p < 0.01), MADRS (β = −0.30, t = −2.93, p < 0.01), and sleep medication use (β = −0.45, t = −2.55, p < 0.05) were significant predictors of QOL in this model (F_{4, 75} = 20.28; p < 0.0001). The relationship of these factors with subdomains of QOL showed that poorer social QOL was associated with greater biological rhythm disturbance (β = −0.43, t = −3.66, p < 0.01) and sleep medication use (β = −0.49, t = −2.35, p < 0.01), providing support for the social rhythm theory of BD. Physical QOL was associated with depression (β = −0.30, t = −2.93, p < 0.01) and biological rhythm disruption (β = −0.31, t = −2.73, p < 0.01). Main limitations include the cross-sectional assessment and the lack of objective measures of biological rhythms in relation to QOL.

Conclusions

Disruption in biological rhythm is associated with poor QOL in BD, independent of sleep disturbance, sleep medication use, and severity of depression. Treatment strategies targeting regulation of biological rhythms, such as sleep/wake cycles, eating patterns, activities, and social rhythms, are likely to improve QOL in this population.

Exponential state transition dynamics in the rest-activity architecture of patients with bipolar disorder

OBJECTIVE

Our goal was to model the temporal dynamics of sleep-wake transitions, represented by transitions between rest and activity obtained from actigraphic data, in patients with bipolar disorder using a probabilistic state transition approach.

METHODS

We collected actigraphic data for 14 days from 20 euthymic patients with bipolar disorder, who had been characterized clinically, demographically, and with respect to their circadian preferences (chronotype). We processed each activity record to generate a series of transitions in both directions between the states of rest (R) and activity (A) and plotted the estimated transition probabilities (pRA and pAR). Each 24-hour period was also divided into a rest phase consisting of the eight consecutive least active hours in each day and an active phase consisting of the 16 consecutive most active hours in each day. We then calculated separate transition probabilities for each of these phases for each participant. We subsequently modeled the rest phase data to find the best fit for rest-activity transitions using maximum likelihood estimation. We also examined the association of transition probabilities with clinical and demographic variables.

RESULTS

The best-fit model for rest-activity transitions during the rest phase was a mixture (bimodal) of exponential functions. Of those patients with rapid cycling, 75% had an evening-type chronotype. Patients with bipolar II disorder taking antidepressants had a lower probability of transitioning back to rest than those not on antidepressants [mean ± SD = 0.050 ± 0.006 versus 0.141 ± 0.058, F(1,15) = 3.40, p < 0.05].

CONCLUSIONS

The dynamics of transitions between rest and activity in bipolar disorder can be accounted for by a mixture (bimodal) of exponential functions. Patients taking antidepressants had a reduced probability of sustaining and returning to sleep.

Differences in sleep disturbances among offspring of parents with and without bipolar disorder: association with conversion to bipolar disorder

OBJECTIVES

Disruptions in sleep and dysregulation in circadian functioning may represent core abnormalities in the pathophysiology of bipolar disorder (BP). However, it is not clear whether these dysfunctions are state or trait markers of BP. This report compared sleep and circadian phenotypes among three groups: offspring of parents with BP diagnosed with BP at intake (BP/OB; n = 47), offspring of parents with BP without BP at intake (non-BP/OB; n = 386), and offspring of matched control parents who did not have BP (controls; n = 301). We also examined the association of baseline sleep parameters with subsequent development of BP among the non-BP/OB group.

METHODS

Pittsburgh Bipolar Offspring Study youth (ages 6-18 years) and their parents completed assessments every two years pertaining to the child's sleep and circadian phenotypes and current psychopathology. Mixed-effects models examined differences in baseline sleep and circadian variables among the three groups.

RESULTS

BP/OB offspring who were in a mood episode differed significantly on sleep parameters from the non-BP/OB and the offspring of controls, such as having inadequate sleep. Mixed logistic regression procedures showed that baseline sleep and circadian variables, such as frequent waking during the night, significantly predicted the development of BP among non-BP/OB over longitudinal follow-up.

CONCLUSIONS

While lifetime diagnostic status accounted for differences among the groups in sleep and circadian disturbances, psychopathology explained the differences even further. Additionally, sleep disturbance may be a prognostic indicator of the development of BP in high-risk youth. Future studies are required to further disentangle whether sleep and circadian disruption are state or trait features of BP.

Chronobiology of bipolar disorder: therapeutic implication

Multiple lines of evidence suggest that psychopathological symptoms of bipolar disorder arise in part from a malfunction of the circadian system, linking the disease with an abnormal internal timing. Alterations in circadian rhythms and sleep are core elements in the disorders, characterizing both mania and depression and having recently been shown during euthymia. Several human genetic studies have implicated specific genes that make up the genesis of circadian rhythms in the manifestation of mood disorders with polymorphisms in molecular clock genes not only showing an association with the disorder but having also been linked to its phenotypic particularities. Many medications used to treat the disorder, such as antidepressant and mood stabilizers, affect the circadian clock. Finally, circadian rhythms and sleep researches have been the starting point of the developing of chronobiological therapies. These interventions are safe, rapid and effective and they should be considered first-line strategies for bipolar depression.

The longitudinal course of sleep timing and circadian preferences in adults with bipolar disorder

OBJECTIVES

To study the longitudinal course of sleep timing and circadian preferences in individuals with bipolar disorder (BP) compared to individuals with non-BP psychopathology and healthy controls.

METHODS

Individuals with bipolar I and bipolar II disorder (n = 257), non-BP psychopathology (n = 105), and healthy controls (n = 55) (mean age 40.2 years, 21.3% male, 85.1% Caucasian) were followed on average every 27 months for a mean of four years. Sleep timing parameters and circadian preference were reported using the Sleep Timing Questionnaire and The Composite Scale for Morningness. Group comparisons were adjusted for multiple comparisons and between-group differences in demographic variables and psychopharmacological treatment.

RESULTS

Regardless of their current mood state, individuals with BP showed more sleep onset latency (SOL), wakening after sleep onset (WASO), and evening preference in comparison to both individuals with non-BP psychopathology and healthy controls. Individuals with BP also showed less stability of bed and awakening times in comparison to the other two groups, though these results were dependent on mood state. Non-BP individuals only showed more WASO and less stability in bed and awakening times before work/school days than healthy controls. Adjusting for comorbid disorders yielded similar results. Within-group analyses found little to no effect of time and BP subtype on sleep timing and circadian preference.

CONCLUSIONS

Disturbances of sleep timing are prominent in individuals with BP. These disturbances are worse during mood episodes, but still apparent during euthymic periods. Evening preference was not associated with polarity type, or mood state in BP, suggesting that this characteristic may be a trait marker.

Risk factors for sleep apnea in children with bipolar disorder

BACKGROUND

While studies have suggested an increased prevalence of Obstructive Sleep Apnea (OSA) in adults with Bipolar Disorder (BPD), little is published about children with BPD. Behavioral difficulties including emotional liability, depression and poor school performance are commonly reported in children with either BPD or OSA. Comorbid medical disorders may exacerbate the course of BPD. We reviewed demographic and polysomnogram characteristics of children with BPD to help outpatient identification of OSA.

METHODS

A single center retrospective chart review of children with BPD referred for a polysomnogram (PSG) over a ten-year period was conducted. There were 27 children identified whose diagnosis of BPD was independently verified by a child psychiatrist using DSM-IV standard criteria.

RESULTS

Six (22%) children had OSA with a median apnea-hyponea index of 7.5 events per hour. Variables that were significantly different between the OSA and non-OSA groups were: median BMI (47 vs 30 kg/m(2), p=0.001); sleep efficiency (78.2% vs 91%, p=0.009); and oxygen saturation nadir (82% vs 92%, p=0.0003). There was no difference found in snoring percentage on PSG between the two groups.

LIMITATIONS

The retrospective design from a single tertiary center limited the cohort size. Only secondary verification of the diagnosis of BPD from the available medical record was possible.

CONCLUSIONS

Our findings suggest that extreme obesity (BMI >40 kg/m(2)), oxygen desaturation during sleep and frequent nocturnal awakenings are associated with OSA in children with BPD. Traditional clinical parameters for obesity and snoring, per se, are poor predictors of OSA in children with BPD.

The relationship between sleep-wake cycle and cognitive functioning in young people with affective disorders

Although early-stage affective disorders are associated with both cognitive dysfunction and sleep-wake disruptions, relationships between these factors have not been specifically examined in young adults. Sleep and circadian rhythm disturbances in those with affective disorders are considerably heterogeneous, and may not relate to cognitive dysfunction in a simple linear fashion. This study aimed to characterise profiles of sleep and circadian disturbance in young people with affective disorders and examine associations between these profiles and cognitive performance. Actigraphy monitoring was completed in 152 young people (16–30 years; 66% female) with primary diagnoses of affective disorders, and 69 healthy controls (18–30 years; 57% female). Patients also underwent detailed neuropsychological assessment. Actigraphy data were processed to estimate both sleep and circadian parameters. Overall neuropsychological performance in patients was poor on tasks relating to mental flexibility and visual memory. Two hierarchical cluster analyses identified three distinct patient groups based on sleep variables and three based on circadian variables. Sleep clusters included a ‘long sleep’ cluster, a ‘disrupted sleep’ cluster, and a ‘delayed and disrupted sleep’ cluster. Circadian clusters included a ‘strong circadian’ cluster, a ‘weak circadian’ cluster, and a ‘delayed circadian’ cluster. Medication use differed between clusters. The ‘long sleep’ cluster displayed significantly worse visual memory performance compared to the ‘disrupted sleep’ cluster. No other cognitive functions differed between clusters. These results highlight the heterogeneity of sleep and circadian profiles in young people with affective disorders, and provide preliminary evidence in support of a relationship between sleep and visual memory, which may be mediated by use of antipsychotic medication. These findings have implications for the personalisation of treatments and improvement of functioning in young adults early in the course of affective illness.

Sleep in patients with remitted bipolar disorders: a meta-analysis of actigraphy studies

OBJECTIVE

Sleep dysregulation is highly prevalent in bipolar disorders (BDs), with previous actigraphic studies demonstrating sleep abnormalities during depressive, manic, and interepisode periods. We undertook a meta-analysis of published actigraphy studies to identify whether any abnormalities in the reported sleep profiles of remitted BD cases differ from controls.

METHOD

A systematic review identified independent studies that were eligible for inclusion in a random effects meta-analysis. Effect sizes for actigraphy parameters were expressed as standardized mean differences (SMD) with 95% confidence intervals (95% CI).

RESULTS

Nine of 248 identified studies met eligibility criteria. Compared with controls (N=210), remitted BD cases (N=202) showed significant differences in SMD for sleep latency (0.51 [0.28-0.73]), sleep duration (0.57 [0.30-0.84]), wake after sleep onset (WASO) (0.28 [0.06-0.50]) and sleep efficiency (-0.38 [-0.70-0.07]). Moderate heterogeneity was identified for sleep duration (I2=44%) and sleep efficiency (I2=44%). Post hoc meta-regression analyses demonstrated that larger SMD for sleep duration were identified for studies with a greater age difference between BD cases and controls (β=0.22; P=0.03) and non-significantly lower levels of residual depressive symptoms in BD cases (β=-0.13; P=0.07).

CONCLUSION

This meta-analysis of sleep in remitted bipolar disorder highlights disturbances in several sleep parameters. Future actigraphy studies should pay attention to age matching and levels of residual depressive symptoms.

Prefronto-cerebellar transcranial direct current stimulation improves sleep quality in euthymic bipolar patients: a brief report

INTRODUCTION

Sleep problems are common in bipolar disorder (BD) and may persist during the euthymic phase of the disease. The aim of the study was to improve sleep quality of euthymic BD patients through the administration of prefronto-cerebellar transcranial direct current stimulation (tDCS).

METHODS

25 euthymic outpatients with a diagnosis of BD Type I or II have been enrolled in the study. tDCS montage was as follows: cathode on the right cerebellar cortex and anode over the left dorsolateral prefrontal cortex (DLPFC); the intensity of stimulation was set at 2 mA and delivered for 20 min/die for 3 consecutive weeks. The Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep quality at baseline and after the tDCS treatment.

RESULTS

PSQI total score and all PSQI subdomains, with the exception of "sleep medication," significantly improved after treatment.

DISCUSSION

This is the first study where a positive effect of tDCS on the quality of sleep in euthymic BD patients has been reported. As both prefrontal cortex and cerebellum may play a role in regulating sleep processes, concomitant cathodal (inhibitory) stimulation of cerebellum and anodal (excitatory) stimulation of DLPFC may have the potential to modulate prefrontal-thalamic-cerebellar circuits leading to improvements of sleep quality.

Sleep in remitted bipolar disorder: a naturalistic case-control study using actigraphy

INTRODUCTION

Findings from actigraphic studies suggesting that sleep and circadian rhythms are disrupted in bipolar disorder (BD) patients have been undermined by methodological heterogeneity and the failure to adequately address potential confounders.

METHOD

Twenty-six euthymic BD cases and 29 healthy controls (HC), recruited from University Paris-Est and matched for age and gender, were compared on subjective (Pittsburgh Sleep Questionnaire Inventory; PQSI) and objective (mean scores and variability in actigraphy) measures of sleep as recorded by over 21 consecutive days.

RESULTS

Multivariate generalized linear modelling (GLM) revealed significant differences between BD cases and HC for five PSQI items (total score and four subscales), four actigraphy variables (mean scores) and five actigraphy variability measures. Backward stepwise linear regression (BSLR) indicated that a combination of four variables (mean sleep duration, mean sleep latency, variability of the fragmentation index over 21 days, and mean score on PSQI daytime dysfunction sub-scale) correctly classified 89% of study participants as cases or controls (Chi-square=39.81; df=6; p=0.001).

LIMITATIONS

The sample size (although larger than most actigraphy studies) and incomplete matching of cases and controls may have influenced our findings. It was not possible to control for potential effects of psychotropic medication or differences in employment status between groups.

CONCLUSIONS

When potential confounders of sleep and circadian profiles are adequately taken into account (particularly age, gender, daytime sleepiness, mood symptoms, body mass index, and risk of sleep apnoea), a selected subset of quantitative (mean scores) and qualitative (variability) features differentiated euthymic BD cases from HC.