Euthymic Individuals Research Articles

Provincial and connector qualities of somatosensory brain network hubs in bipolar disorder.

Brain network hubs are highly connected brain regions serving as important relay stations for information integration. Recent studies have linked mental disorders to impaired hub function. Provincial hubs mainly integrate information within their own brain network, while connector hubs share information between different brain networks. This study used a novel time-varying analysis to investigate whether hubs aberrantly follow the trajectory of other brain networks than their own. The aim was to characterize brain hub functioning in clinically remitted bipolar patients. We analyzed resting-state functional magnetic resonance imaging data from 96 euthymic individuals with bipolar disorder and 61 healthy control individuals. We characterized different hub qualities within the somatomotor network. We found that the somatomotor network comprised mainly provincial hubs in healthy controls. Conversely, in bipolar disorder patients, hubs in the primary somatosensory cortex displayed weaker provincial and stronger connector hub function. Furthermore, hubs in bipolar disorder showed weaker allegiances with their own brain network and followed the trajectories of the limbic, salience, dorsal attention, and frontoparietal network. We suggest that these hub aberrancies contribute to previously shown functional connectivity alterations in bipolar disorder and may thus constitute the neural substrate to persistently impaired sensory integration despite clinical remission.

Associations between actigraphy estimates of sleep and circadian rhythmicity and psychotropic medications in bipolar disorders: An exploratory study

IntroductionDisturbances in sleep and circadian rhythmicity (CR) are frequent in individuals with bipolar disorders (BD). Very few studies explored the associations between psychotropic medications and these disturbances in euthymic BD. Therefore, we aimed at exploring the associations between several classes of medications (lithium, sedative/non-sedative Atypical Antipsychotics (AAP), anticonvulsants, antidepressants, benzodiazepines) and sleep disturbances and CR dimensions in a sample of euthymic individuals with BD. MethodsWe included euthymic adults with BD type 1 or 2 assessed with 21 days of actimetry. We used a Principal Component Analysis (PCA) of sleep and CR estimates to generate dimensions to be studied in association with the current use of psychotropic medications, with adjustments for potential confounding factors. ResultsWe included individuals with BD-1 (n = 116) or BD-2 (n = 37). The PCA led to four dimensions of sleep and CR estimates. Benzodiazepines were associated with better sleep quality (pcorrected = 0.032). Aripiprazole was associated with less robust CR (pcorrected = 0.016), but with earlier peak of activity patterns (pcorrected = 0.020). Sedative AAPs were associated with better sleep quality, which was no longer significant after correction. We found no association between lithium or anticonvulsants and CR. LimitationsThe cross-sectional design and the possible non-representativeness of the sample were limitations of our study. ConclusionsIn euthymic individuals with BD, benzodiazepines may have a positive effect on sleep quality, while aripiprazole may have mixed effects on CR (less robust but with earlier peak of activity patterns). No association with lithium or anticonvulsants observed. Further studies are warranted to replicate and extend these results.

Mood correlates with circadian alignment in healthy individuals

ObjectiveTo determine whether there is a correlation between mood and the alignment between the timing of the circadian pacemaker (circadian phase) and the timing of sleep in healthy, euthymic individuals. MethodsParticipants were 25 first-year medical students (25.9 ± 3.3years, 16 females). Mood (Profile of Mood States, brief form) and circadian phase (salivary dim light melatonin onset) were assessed 4 times over 7weeks. Circadian alignment was determined using the dim light melatonin onset to average midsleep interval (phase angle difference). ResultsProfile of Mood States, brief form score and phase angle difference were correlated: later dim light melatonin onset relative to midsleep (shorter phase angle differences) was associated with worse mood (F1,75 =10.953, p = .001). There was no difference in Profile of Mood States, brief form score between female and male participants and no interaction between gender and phase angle difference. ConclusionsThere is a correlation between circadian alignment and mood among healthy individuals as has been found in individuals with seasonal and nonseasonal depression. This finding has implications for the development, prevention and treatment of mood disorders.

Pilot study of a ketogenic diet in bipolar disorder.

Recent evidence from case reports suggests that a ketogenic diet may be effective for bipolar disorder. However, no clinical trials have been conducted to date. To assess the recruitment and feasibility of a ketogenic diet intervention in bipolar disorder. Euthymic individuals with bipolar disorder were recruited to a 6-8 week trial of a modified ketogenic diet, and a range of clinical, economic and functional outcome measures were assessed. Study registration number: ISRCTN61613198. Of 27 recruited participants, 26 commenced and 20 completed the modified ketogenic diet for 6-8 weeks. The outcomes data-set was 95% complete for daily ketone measures, 95% complete for daily glucose measures and 95% complete for daily ecological momentary assessment of symptoms during the intervention period. Mean daily blood ketone readings were 1.3 mmol/L (s.d. = 0.77, median = 1.1) during the intervention period, and 91% of all readings indicated ketosis, suggesting a high degree of adherence to the diet. Over 91% of daily blood glucose readings were within normal range, with 9% indicating mild hypoglycaemia. Eleven minor adverse events were recorded, including fatigue, constipation, drowsiness and hunger. One serious adverse event was reported (euglycemic ketoacidosis in a participant taking SGLT2-inhibitor medication). The recruitment and retention of euthymic individuals with bipolar disorder to a 6-8 week ketogenic diet intervention was feasible, with high completion rates for outcome measures. The majority of participants reached and maintained ketosis, and adverse events were generally mild and modifiable. A future randomised controlled trial is now warranted.

What's in the mind's eye of individuals with bipolar disorders: an exploration of the content and characteristics of mental images in different thymic phases.

Mental imagery, or 'seeing with the mind's eye' (Kosslyn et al. ), provokes strong emotional responses (Ji et al., ). To date, there is a lack of data on the content and clinical characteristics (e.g. vividness, likelihood, emotional effects) of spontaneous mental images (MI) in people with bipolar disorder (BD) according to their thymic states. The current study sought to assess the characteristics associated with the contents of MI in people with BD. Forty-two euthymic individuals diagnosed with BD (American Psychiatric Association, ) were asked to self-report their MI during depression, (hypo)mania and euthymia. Participants also rated levels of vividness, likelihood and emotional activation related to MI (i.e. valence, arousal, type of emotion). The contents of the MI revealed phenomenological aspects of BD. Different themes were associated with each thymic phase. In (hypo)mania and in euthymia, the mental images were assessed as being as vivid as probable (p>.05). (Hypo)manic and euthymic-related MI activated more pleasure than displeasure (p<.001) and were mainly associated with joy. In depression, MI were assessed as more vivid than likely (p<.05). In depression, MI activated more displeasure than pleasure (p<.0001) and induced mainly sadness. Overall, a congruence between the contents of images and the three thymic phases was found. The content of the MI was related to self-reported emotional effects that were congruent with the thymic phases concerned. The results add new clinical information for the use of imagery-based cognitive therapy in individuals with BD.

A transdiagnostic approach to negative symptoms: exploring factor structure and negative symptoms in bipolar disorders.

Negative symptoms are increasingly recognized as transdiagnostic phenomena, linked to reduced quality of life and functioning, and often caused or worsened by amendable external factors such as depression, social deprivation, side-effects of antipsychotics or substance use. The structure of negative symptoms fits into two dimensions: diminished expression and apathy. These may differ in association with external factors that influence their severity and may thus require different treatment approaches. The dimensions are comprehensively established in non-affective psychotic disorders but are understudied in bipolar disorders. We conducted exploratory and confirmatory factor analyses in a sample of 584 individuals with bipolar disorder to assess the latent factor structure of negative symptoms as measured by the Positive and Negative Syndrome Scale (PANSS), and performed correlational analyses and multiple hierarchical regression analyses to investigate links between the two dimensions of negative symptoms and clinical and sociodemographic correlates. The latent factor structure of negative symptoms fits into two dimensions, i.e., diminished expression and apathy. A diagnosis of bipolar type I or a history of psychotic episodes predicted more severe levels of diminished expression. Depressive symptoms were associated with more severe negative symptoms across dimensions, yet 26.3% of euthymic individuals still displayed at least one mild or more severe negative symptom (PANSS score ≥ 3). The two-dimensional structure of negative symptoms seen in non-affective psychotic disorders reproduces in bipolar disorders indicating similarities in their phenomenology. Diminished expression was associated with a history of psychotic episodes and a diagnosis of BD-I, which may infer closer connections to psychosis liability. We found significantly less severe negative symptoms in euthymic than depressed participants. Nevertheless, more than a quarter of the euthymic individuals had at least one mild negative symptom, demonstrating some degree of persistence beyond depressed states.

The Big Five as Predictors of Cognitive Function in Individuals with Bipolar Disorder.

The connection between cognitive function and the "Big Five" personality traits (openness, conscientiousness, extraversion, agreeableness, and neuroticism) in the general population is well known; however, studies researching bipolar disorder (BD) are scarce. Therefore, this study aimed to investigate the Big Five as predictors of executive function, verbal memory, attention, and processing speed in euthymic individuals with BD (cross-sectional: n = 129, including time point t1; longitudinal: n = 35, including t1 and t2). Participants completed the NEO Five-Factor Inventory, the Color and Word Interference Test, the Trail Making Test, the d2 Test of Attention Revised, and the California Verbal Learning Test. The results showed a significant negative correlation between executive function and neuroticism at t1. Changes in cognitive function between t1 and t2 did not correlate with and could not be predicted by the Big Five at t1. Additionally, worse executive function at t2 was predicted by higher neuroticism and lower conscientiousness at t1, and high neuroticism was a predictor of worse verbal memory at t2. The Big Five might not strongly impact cognitive function over short periods; however, they are significant predictors of cognitive function. Future studies should include a higher number of participants and more time in between points of measurement.

Temporal self and reflected appraisals in euthymic and depressed individuals

BackgroundTemporal self-appraisal (TSA) theory, reflected appraisal theory, and their clinical applications have previously been explored as independent constructs. This study investigates how TSA corresponds to temporal reflected appraisal (TRA), and how the relationship between them differs in the presence of depression. Methods273 adults (57 % female), recruited using Amazon Mechanical Turk, filled out a series of measures of mood and self-appraisal assessments (TSA and TRA versions of the Me/Not Me task). Repeated measures MANOVAs were used to assess between group differences. ResultsThe TSA trajectory of depressed individuals replicated the ‘V' shape found in previous research, whereas the TRA of depressed individuals did not decline from past to present. There was little difference between TSA and TRA “past” and “future” appraisals, though there was a significant difference in appraisal of the “present.” Individuals with depression believe that others perceive them as doing much better currently than the way they view themselves. By contrast, euthymic individuals had no significant differences between the TSA and TRA appraisals of their present selves, indicating they think their self-perception matches how others view them. LimitationsWe assessed depression using online self-reports. Cross-sectional data limits causality determination but suffices for studying mood-related self-perceptions over time. ConclusionsTemporal self-appraisal and temporal reflected appraisal have varying relationships among euthymic and depressed individuals. This more precise characterization of depressed individuals' identity can further aid clinicians in understanding the nature of identity development and treating identity disruption among depressed individuals.

Psychiatric comorbidity in individuals with bipolar disorder: relation with clinical outcomes and functioning.

The aim was to assess the lifetime prevalence of psychiatric comorbidity (PC) in Brazilian euthymic individuals with bipolar disorder type I, and investigate its effects on clinical outcomes and functioning. A group of 179 outpatients with BD-I in the recuperation phase were assessed, of whom 75 (41.9%) had PC and 104 (58.1%) had not. Both groups were compared using sociodemographic/clinical questionnaire, Structured Clinical Interview for DSM-IV axis I and II, Sheehan Disability and Barratt Impulsiveness Scales. Patients with PC presented less religious affiliation, more history of lifetime psychotic symptoms, rapid cycling, suicide attempts, worse scores of functioning, and higher prevalence of personality disorders. Ordinal logistic regression indicated that PC was associated with increased odds of worse levels of disability. Therefore, it could be observed that patients with BD evaluated only in euthymia presented a high mental disorders comorbidity. Considering their burdensome impact, appropriate management is a challenging reality and a crucial factor in reducing morbidity and mortality associated with BD. Further longitudinal studies on their relationship may broaden interventions to reduce patient's suffering.

Functional connectivity alterations of the somatomotor network in euthymic bipolar disorder

While individuals with bipolar disorder are assumed to recover between mood episodes, some nevertheless experience lingering subsyndromal symptoms and suffer from cognitive and functional impairments. Here, we propose that these enduring impairments may be linked to aberrations in brain networks. To test this, we conducted a resting-state functional magnetic resonance imaging (fMRI) study and used network-based statistic to compare functional connectivity between euthymic individuals with bipolar disorder (N = 96) and healthy control individuals (N = 61) both within and between resting-state networks. We also investigated the association of functional connectivity with lingering psychomotor symptoms and illness severity in bipolar disorder. We found stronger functional connectivity between the somatomotor network and the frontoparietal network in individuals with bipolar disorder compared with healthy controls, but weaker functional connectivity within the somatomotor network as well as between the somatomotor and the visual network. Results remained after adjusting for antipsychotic medication. No significant association with psychomotor performance and illness severity was found. We conclude that stronger functional connectivity between the somatomotor and frontoparietal network might be associated with lingering symptoms in bipolar euthymia. Dysconnectivity within the somatomotor network might relate to psychomotor symptoms beyond the impact of medication. Our findings contribute to the sparse field of somatomotor network aberrancies in bipolar disorder and may present a potential target for brain stimulation treatment.

Childhood trauma and neurocognitive functions in individuals with bipolar disorder and unaffected siblings of individuals with bipolar disorder

Previous studies have suggested a possible connection between childhood trauma, the course of illness, and neurocognitive impairment in individuals with bipolar disorder (BD). This cross-sectional study aimed to investigate the relationship between childhood trauma and neurocognitive functioning in a sample consisting of 41 euthymic individuals with BD, 37 individuals who have at least one sibling with BD, and 48 healthy controls (HCs). We assessed childhood trauma history using the Childhood Trauma Questionnaire (CTQ). Both the BD and Sibling groups showed higher rates of emotional abuse, neglect, and higher total trauma scores compared to the HCs. A principal component analysis of the neurocognitive test battery revealed a global cognition factor responsible for 49.40% of the variance and five subsequent neurocognitive components: working memory & response inhibition, verbal memory, visual copying, verbal fluency, and processing speed. Individuals with BD had lower scores in verbal memory, visual copying, processing speed, and global cognitive factor domains than the Siblings and HCs. The Siblings' performance was similar to that of the HC group. Correlation analyses showed significant correlations between physical neglect, sexual abuse, and neurocognitive domains like processing speed, verbal fluency, working memory, and the global cognitive factor. However, the linear regression analyses didn’t reveal a significant influence of childhood trauma on neurocognitive domains. Our findings indicate that both individuals with BD and their unaffected siblings have a high occurrence of childhood trauma, but presence of bipolar disorder itself appears to influence neurocognitive functioning independently of childhood traumatic experiences or familial predisposition to bipolar disorder.

Gene expression of circadian genes and CIART in bipolar disorder: A preliminary case-control study

Based on the observed circadian rhythms disruptions and sleep abnormalities in bipolar disorders (BD), a chronobiological model has been proposed suggesting that core clock genes play a central role in the vulnerability to the disorder. In this context, the analysis of circadian genes expression levels is particularly relevant, however studies focused on the whole set of core clock genes are scarce. We compared the levels of expression of 19 circadian genes (including the recently described circadian repressor (CIART)) in 37 euthymic individuals with BD and 20 healthy controls (HC), using data obtained by RNA sequencing of lymphoblastoid cell lines and validated the results using RT-qPCR. RNA sequencing data showed that CIART gene expression was correlated with those of ARNTL, ARNTL2, DBP, PER2 and TIMELESS. Data from RNA sequencing showed that the level of expression of four circadian genes (ARNTL, ARNTL2, BHLHE41 and CIART) discriminated individuals with BD from HC. We replicated this result using RT-qPCR for ARNTL and CIART. This study suggests that an imbalance between activation/repression of the transcription within the circadian system in individuals with BD as compared to HC and as such opens avenues for further research in larger independent samples combining both expression and epigenetic analyses.

Lack of speeded disengagement from facial expressions of disgust in remitted major depressive disorder: Evidence from an eye-movement study

Acute major depression is characterized by specific abnormalities in the way emotional material is attended to. In late stages of stimulus processing, clinically depressed and dysphoric individuals show difficulties to disengage attention from emotionally negative material. It is unclear, however, whether aberrant disengagement is a transitory attentional phenomenon tied to depressive symptoms, or whether it constitutes a more stable disposition that outlast the symptomatic episode. To address this issue, the current study examined 39 currently euthymic individuals previously affected by major depression (RMD) and 40 healthy control participants reporting no lifetime psychopathology (ND). We used a gaze-contingent eye tracking paradigm designed to separately assess the attentional components of engagement and disengagement when viewing facial expressions of sadness, disgust and happiness. Never-depressed healthy participants, but not remitted euthymic individuals, showed speeded disengagement from facial expressions of disgust. We propose that the lack of this distinct acceleration in previously depressed but fully remitted individuals might reflect an attentional disposition that carries over to euthymic phases of the disease. On the other hand, a tendency to disengage quickly from areas in the visual field that convey social disdain could potentially act as a protective, possibly mood-stabilizing bias in resilient individuals.

Which Actigraphy Dimensions Predict Longitudinal Outcomes in Bipolar Disorders?

Bipolar disorder (BD) is characterized by recurrent mood episodes. It is increasingly suggested that disturbances in sleep–wake cycles and/or circadian rhythms could represent valuable predictors of recurrence, but few studies have addressed this question. Euthymic individuals with BD (n = 69) undertook 3 weeks of actigraphy recording and were then followed up for a median duration of 3.5 years. Principal component analyses were used to identify core dimensions of sleep quantity/variability and circadian rhythmicity. Associations between clinical variables and actigraphy dimensions and time to first recurrence were explored using survival analyses, and then using area under the curve (AUC) analyses (early vs. late recurrence). Most participants (64%) experienced a recurrence during follow-up (median survival time: 18 months). After adjusting for potential confounding factors, an actigraphy dimension comprising amplitude and variability/stability of circadian rhythms was a significant predictor of time to recurrence (p = 0.009). The AUC for correct classification of early vs. late recurrence subgroups was only 0.64 for clinical predictors, but combining these variables with objectively measured intra-day variability improved the AUC to 0.82 (p = 0.04). Actigraphy estimates of circadian rhythms, particularly variability/stability and amplitude, may represent valid predictive markers of future BD recurrences and could be putative targets for future psychosocial interventions.

Associations between comorbid anxiety and sleep disturbance in people with bipolar disorder: Findings from actigraphy and subjective sleep measures

BackgroundStudies show that comorbid anxiety disorders are common in people with bipolar disorder. However, little is known about whether this anxiety is associated with sleep disturbance. We investigated, in individuals with bipolar disorder, whether comorbid anxiety disorder is associated with sleep disturbance. MethodsParticipants were 101 (64% female) currently euthymic individuals with a history of bipolar disorder. Sleep disturbances were assessed using self-report measures of sleep quality (Pittsburgh Sleep Quality Index, PSQI) and six weeks of sleep monitoring using actigraphy. Bipolar disorder and comorbid anxiety diagnoses were assessed using the Mini International Neuropsychiatric Interview. Multiple regression analyses examined associations between comorbid anxiety and sleep disturbance, whilst controlling for confounding covariates known to impact on sleep. ResultsA comorbid anxiety disorder was associated with increased sleep disturbance as measured using the PSQI global score (B = 3.58, 95% CI 1.85–5.32, P < 0.001) but was not associated with sleep metrics (total sleep time, sleep onset latency, sleep efficiency, and wake after sleep onset) derived using actigraphy. LimitationsObjective measures of sleep were limited to actigraphy, therefore we were not able to examine differences in sleep neurophysiology. ConclusionsClinicians should be aware that comorbid anxiety may increase the risk of experiencing subjective sleep disturbance in people with bipolar disorder. Research should assess for evidence of comorbid anxiety when examining associations between sleep and bipolar disorder. Future research should explore the mechanisms by which comorbid anxiety may contribute to subjective sleep disturbances in bipolar disorder using neurophysiological measures of sleep (i.e., polysomnography).

Nutrition, Overweight, and Cognition in Euthymic Bipolar Individuals Compared to Healthy Controls.

Bipolar disorder (BD) is associated with impairments in cognitive functions, in which metabolic factors, e.g., overweight, seem to play a significant role. The aim of this study was to investigate the association between nutritional factors and cognitive performance in euthymic individuals with BD. A study cohort of 56 euthymic individuals with BD was compared to a sample of 53 mentally healthy controls. To assess cognitive function, the following tests were applied: California Verbal Learning Test, Trail Making Test A/B, d2 Test of Attention-Revised, and Stroop’s Color-Word Interference Test. Furthermore, a 4-day food record was processed to evaluate dietary intake of macronutrients, specific micronutrients, and food diversity. Body mass index and waist to height ratio were calculated to assess overweight and central obesity. Results showed no nutritional differences between individuals with BD and controls. Individuals with BD performed worse in the d2 test than controls. Hierarchical regression analyses yielded no association between cognitive and nutritional parameters. However, waist to height ratio was negatively correlated with almost all cognitive tests. Central obesity seems to affect cognitive functioning in BD, while the lack of finding differences in nutritional data might be due to problems when collecting data and the small sample size. Consequently, further studies focusing on objectively measuring food intake with adequate sample size are needed.

Anxiety and temporal self-appraisal: How people with anxiety evaluate themselves over time

BackgroundPrevious studies found that psychopathology is associated with distinct self-perceptions over time. Euthymic individuals report experiencing a self-enhancement bias, with self-appraisal increasing over time. In contrast, depressed individuals report viewing a personal decline from past to present and anticipated self-improvement from present to future. This study examined the association between the singular presence of anxiety and temporal self-appraisal. MethodsUsing the Depression Anxiety and Stress Scale, this study examined a depressed (n = 142), anxious (n = 95), comorbid depressed and anxious (n = 335), and euthymic group (non-depressed and non-anxious, n = 535), on a validated task of temporal self-appraisal. ResultsAnxiety has a unique association with temporal self-appraisal that differs from the other disorders examined in this study. Specifically, individuals with anxiety had a similar positive trend of self-view to the euthymic group; however, their overall trend was lower at each temporal point. Individuals with depression had a stable past-to-present self-view and an improving present-to-future self-view. LimitationsThe use of an online self-report sample without longitudinal assessment of variables, while sufficient for the intent of the present study, limits the potential extrapolation from this sample, as well as prevents the determination of the direction of causality. ConclusionsWhile individuals with anxiety demonstrate a positive sense of improvement over time, their psychopathology is associated with a negative bias in their perception of their past, present, and future selves. These findings have important implications for clinicians regarding potential interventions and treatment for anxiety and depression.

Sex differences in zonulin in affective disorders and associations with current mood symptoms

IntroductionThe bidirectional connection between the brain and the gut within psychiatric entities has gained increasing scientific attention over the last years. As a regulator of intestinal permeability, zonulin acts as a key player on the interface of this interplay. Like several psychiatric disorders, intestinal permeability was associated with inflammation in previous findings. MethodsIn this study we explored differences in zonulin serum levels in currently depressed (n = 55) versus currently euthymic (n = 37) individuals with an affective disorder. Further, we explored sex differences and possible influences on zonulin and affective symptoms like medication, age, body mass index, and smoking status. ResultsSerum zonulin was significantly higher in females than in men independent from affective status (z = -2.412, p = .016). More specifically, females in the euthymic subgroup had higher zonulin levels than euthymic men (z = -2.114, p = .035). There was no difference in zonulin serum levels in individuals taking or not taking a specific psychopharmacotherapy. We found no correlation between zonulin serum levels and depression severity. DiscussionIncreased serum zonulin levels as a proxy for increased intestinal permeability in women may indicate a state of elevated susceptibility for depression-inducing stimuli.

Understanding familial liability for emotion regulation difficulties in bipolar disorder.

There has been relatively limited work focused on understanding whether relatives of individuals with bipolar disorder (BD) have difficulties in the regulation of emotion, particularly in relation to perceptions about whether emotions can be effectively regulated, or trait behaviours that acknowledge emotions as self-regulators themselves. In this study, we assessed the presence and extent of difficulties in these dimensions of emotion regulation in individuals with BD compared to unaffected first-degree biological relatives (FDR) for the first time. In total, 161 participants, including euthymic individuals with BD, unaffected FDRs, and healthy controls, were compared on the Difficulties in Emotion Regulation Scale (DERS) - a multi-dimensional measure of habitual emotion regulation. Clinical data were also collected and examined in relation to DERS scores in a secondary analysis. In the BD group, difficulties were evident for most dimensions of emotion regulation as measured by the DERS; and correlated with an earlier onset of illness and more mood episodes. FDRs displayed generally normal emotion regulation, except in terms of their beliefs that emotions can be effectively regulated; on this dimension, their reported difficulty was intermediate to the BD group and controls. Habitual emotion regulation difficulties in BD persist irrespective of mood state, are related to the course of illness, and should be targeted in psychological interventions. Further, the perception that emotions cannot be effectively regulated during times of distress seems to represent an endophenotype for BD.

Misperception of sleep in bipolar disorder: an exploratory study using questionnaire versus actigraphy

BackgroundThe concept of misperception of sleep refers to the estimated discrepancy between subjective and objective measures of sleep. This has been assessed only in a few prior studies in individuals with Bipolar Disorder (BD) as compared to Healthy Controls (HC) and with mixed results.MethodsWe assessed a sample of 133 euthymic individuals with BD and 63 HC for retrospective subjective (Pittsburgh Sleep Quality Index) and objective (21 days of actigraphy recording) measures of total sleep time, sleep latency and sleep efficiency. We first investigated the correlations between these subjective and objective measures in the two groups. We then compared individuals with BD and HC for the absolute values of the differences between subjective and objective sleep parameters, used as a proxy of the magnitude of misperception of sleep. Finally, we undertook regression analyses to assess associations between clinical groups, core demographics, clinical factors and misperception of sleep.ResultsThe correlation coefficients between subjective and objective measures of sleep did not differ between groups (total sleep time: rho = .539 in BD and rho = .584 in HC; sleep latency: rho = .190 in BD and rho = .125 in HC; sleep efficiency: rho = .166 in BD and rho = .222 in HC). Individuals with BD did not differ from HC in the magnitude of misperception of total sleep time, sleep latency nor sleep efficiency. Individuals with BD type 1 misperceived their sleep efficiency significantly more than individuals with BD type 2, with no further difference between BD type 1 and BD type 2 regarding sleep latency and sleep duration misperceptions. Three factors (age, symptoms of obstructive sleep apnea, and mild depressive symptoms), were the main contributors to the magnitude of misperception of sleep.ConclusionsMisperception of sleep was not associated with a diagnosis of BD. In this sample, mild depressive symptoms, older age, or symptoms of obstructive sleep apnea may be related to greater sleep misperception. In that case, the reliability of subjective measures may decrease as the misperception of sleep increases. This study may help guide clinicians in selecting the best approach for assessing sleep (objective versus subjective measures) in individuals with BD.