Performance of a measure to assess distress in bipolar disorder

INTRODUCTION

Bipolar disorder is a condition that causes distress even for euthymic patients, having an impact on functional capabilities and quality of life. Personal and social variables are potential sources of distress. Yet, there is a lack of measures to identify specific distress in bipolar disorder. This study describes the development and evaluation of a brief measure for assessing distress in patients with bipolar disorder. We also identify associations with related constructs such as functioning, stigma, and personal beliefs regarding mental illness.

MATERIAL AND METHODS

We used a sample of 101 euthymic bipolar outpatients. Psychological assessment consisted of the Young Mania Rating Scale (YMRS) and the Hamilton Depression Scale (HAM-D) to establish euthymia. Distress was assessed with Distress on Bipolar Patients-Short (DISBIP-S); associated variables were assessed with the Functioning Assessment Short Scale (FAST), the Internalized Stigma of Mental Illness (ISMI), and the Personal Beliefs about Illness Questionnaire (PBIQ).

RESULTS

The DISBIP-S has strong internal consistency (Cronbach's alpha=0.90), and medium-high correlation coefficients with the time since last relapse (r=-0.401), predominant polarity (r=0.309), HDRS (r=-0.644), FAST (r=0.453), ISMI (r=0.789), and PBIQ (r=-0.796). Taken together, the scores on the ISMI, and PBIQ and the time since last relapse together explain 69.2% of the variability in distress.

CONCLUSIONS

The DISBIP-S can be used as a first step to develop interventions aimed at dealing with problematic personal beliefs and interpersonal sources of distress. Reducing distress experienced by bipolar disorder patients could help improve their quality of life and daily functioning.

Neuropsychological aspects of bipolar disorder

Bipolar disorder (BD) is a chronic condition with serious consequences on the health and functionality of patients who suffer from it, with a high heritability and segregation, and aprevalence of between 1% and 2%. Neuropsychological deficits have been implicated as a very important issue related to BD prognosis, so a review was conducted of these deficits, the related factors and their functional consequences. It has been determined that the presence of neuropsychological deficits can vary in patients with BD according to their mood state, with a great influence of depressive symptoms on the cognitive variability of patients with respect to the general population and differences with respect to patients in the manic phase. In euthymic patients, the most affected cognitive domains are those of memory, attention, and executive function, associated with a more severe disease, sociodemographic vulnerability factors, and stable over time. A relationship has been found between poor cognitive performance, especially executive dysfunction, and objective functional deficit. Furthermore, cognitive differences have been outlined between BD and other serious mental illnesses that are described in this review.

Default mode network shows alterations for low-frequency fMRI fluctuations in euthymic bipolar disorder

Bipolar disorder (BD) is a psychiatric condition causing acute dysfunctional mood states and emotion regulation. Specific neuropsychological features are often present also among patients in euthymic phase, who do not show clear psychotic symptoms, and for whom the characterization from functional magnetic resonance imaging (fMRI) is very limited. This study aims at identifying the neural and behavioral correlates of the default mode network (DMN) using the fractional amplitude of low frequency fluctuations (fALFF). Eighteen euthymic BD patients (10 females; age = 54.50 ± 11.38 years) and sixteen healthy controls (HC) (8 females; age = 51.16 ± 11.44 years) underwent a 1.5T fMRI scan at rest. The DMN was extracted through independent component analysis. Then, DMN time series was used to compute the fALFF, which was correlated with clinical scales. From the between-group comparison, no significant differences emerged in correspondence to regions belonging to the DMN. For fALFF analysis, we reported significant increase of low-frequency fluctuations for lower frequencies, and decreases for higher frequencies compared to HC. Correlations with clinical scales showed that an increase in higher frequency spectral content was associated with lower levels of mania and higher levels of anxious symptoms, while an increase in lower frequencies was linked to lower depressive symptoms. Starting from our findings on the DMN in euthymic BD patients, we suggest that the fALFF derived from network time series represents a viable approach to investigate the behavioral correlates of resting state networks, and the pathophysiological mechanisms of different psychiatric conditions.

Neuropsychological Aspects of Bipolar Disorder

Bipolar disorder (BD) is a chronic condition with serious consequences on the health and functionality of patients who suffer from it, with a high heritability and segregation, and a prevalence of between 1% and 2%. Neuropsychological deficits have been implicated as a very important issue related to BD prognosis, so a review was conducted of these deficits, the related factors and their functional consequences. It has been determined that the presence of neuropsychological deficits can vary in patients with BD according to their mood state, with a great influence of depressive symptoms on the cognitive variability of patients with respect to the general population and differences with respect to patients in the manic phase. In euthymic patients, the most affected cognitive domains are those of memory, attention, and executive function, associated with a more severe disease, sociodemographic vulnerability factors, and stable over time. A relationship has been found between poor cognitive performance, especially executive dysfunction, and objective functional deficit. Furthermore, cognitive differences have been outlined between BD and other serious mental illnesses that are described in the review.

Altered dynamic functional connectivity across mood states in bipolar disorder

BACKGROUND

This study aims to identify how the large-scale brain dynamic functional connectivity (dFC) differs between mood states in bipolar disorder (BD). The authors analyzed dFC in subjects with BD in depressed and euthymic states using resting-state functional magnetic resonance imaging (rsfMRI) data, and compared these states to healthy controls (HCs).

METHOD

20 subjects with BD in a depressive episode, 23 euthymic BD subjects, and 31 matched HCs underwent rsfMRI scans. Using an existing parcellation of the whole brain, we measured dFC between brain regions and identified the different patterns of brain network connections between groups.

RESULTS

In the analysis of whole brain dFC, the connectivity between the left Superior Temporal Gyrus (STG) in the somatomotor network (SMN), the right Middle Temporal Gyrus (MTG) in the default mode network (DMN) and the bilateral Postcentral Gyrus (PoG) in the DMN of depressed BD was greater than that of euthymic BD, while there was no significant difference between euthymic BD and HCs in these brain regions. Euthymic BD patients had abnormalities in the frontal-striatal-thalamic (FST) circuit compared to HCs.

CONCLUSIONS

Differences in dFC within and between DMN and SMN can be used to distinguish depressed and euthymic states in bipolar patients. The hyperconnectivity within and between DMN and SMN may be a state feature of depressed BD. The abnormal connectivity of the FST circuit can help identify euthymic BD from HCs.

MicroRNA dysregulation in manic and euthymic patients with bipolar disorder

BACKGROUND

Bipolar disorder (BPD) is a major psychiatric disorder with an unclear pathophysiology. Peripheral blood samples are easily drawn, making them are good candidates for diagnosing diseases. MicroRNAs are small non-coding RNA transcripts that regulate gene expression by binding to the 3'- UTR of mRNAs and directing their degradation. The aim of this study was to use blood plasma to investigate microRNA dysregulations in bipolar manic and euthymic patients.

SUBJECTS AND METHODS

Blood samples were collected from 58 patients with bipolar I disorder (19 manic, 39 euthymic) and 51 healthy controls.

RESULTS

Four microRNAs (miR-29a-3p, p = 0.035; miR-106b-5p, p = 0.014; miR-107, p = 0.011; and miR-125a-3p, p = 0.014) were upregulated in the entire bipolar group, compared to the healthy controls. Seven microRNAs (miR-9-5p, p = 0.032; miR-29a-3p, p = 0.001; miR-106a-5p, p = 0.034; miR-106b-5p, p = 0.003; miR-107, p < 0.001; miR-125a-3p, p = 0.016; and miR-125b-5p, p = 0.004) were more upregulated in bipolar manic patients compared to the healthy controls, and two microRNAs (miR-106a-5p, p = 0.013, and miR-107, p = 0.021) showed statistically significant upregulation in the manic patients compared to the euthymic patients.

CONCLUSIONS

Our results showed greater miRNA dysregulation in the manic patients than in the euthymic patients. Two microRNAs could be more selective for bipolar manic episodes. Future studies should include depressive patients along with euthymic and manic patients.

Quality of life in euthymic bipolar patients: A systematic review and meta-analysis

BACKGROUND

Patients with bipolar disorder, even euthymic, could suffer an impairment in their quality of life compared to healthy controls. Since no previous systematic review and meta-analysis has been conducted, the aim of the current study is to conduct a systematic review and meta-analysis of cross-sectional case-controlled studies on quality of life in adult euthymic Bipolar Disorder patients.

METHODS

A systematic review and meta-analysis that followed the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) was conducted. Major electronic databases were searched on August 2018 to assess the variables associated with quality of life in euthymic bipolar disorder patients. After selecting case-control studies, data collection, quality assessment and subsequently statistical analysis were done.

RESULTS

66 studies were finally selected for systematic review and meta-analysis. Four different quality of life instruments were used among the different studies. Effect size analysis showed that there were significant differences in quality of life outcomes between euthymic bipolar disorder patients and healthy controls (d=-0.922; SE=0.316; 95%CI=-1.541--0.303; p=.004), with lower quality of life in the euthymic patients. Furthermore, time since euthymia explained 15.62% of variability, and age of control group explained 29.6% of variability. No other moderators were statiscally significant.

LIMITATIONS

The instruments used were heterogeneous. Moreover, the role of other clinical moderators could not be included due to the lack of this information in most of the articles.

CONCLUSIONS

Quality of life is lower in euthymic bipolar patients than in healthy controls. However, longer time in euthymia is associated with better outcomes.

Behavioral measures and self-report of impulsivity in bipolar disorder: no association between Stroop test and Barratt Impulsiveness Scale

BACKGROUND

Impulsivity as a tendency to act quickly without considering future consequences has been proposed as a dimensional factor in bipolar disorder. It can be measured using behavioral tasks and self-report questionnaires. Previous findings revealed patients to show worse performance on at least one behavioral measure of impulsivity. Additionally, self-reported impulsivity seems to be higher among bipolar patients, both parameters being possibly associated with a more severe course of illness. In this study, our primary aim was to investigate the relationship between these two constructs of impulsivity among bipolar patients.

METHODS

A total of 40 euthymic patients with bipolar disorder (21 female, 22 Bipolar I) and 30 healthy controls were recruited for comprehensive neuropsychological assessment. To assess inhibition control as a behavioral measure of impulsivity, the Stroop Color and Word Test (Stroop) was used. Additionally, both groups completed the Barratt Impulsiveness Scale (BIS) as a self-report of impulsivity. To compare the groups' performance on the Stroop and ratings on the BIS, the non-parametric Mann-Whitney U test was used. Within the bipolar group, we additionally examined the possibility of an association between Stroop performance and BIS total scores using Pearson's Correlation r.

RESULTS

Patients and controls differed significantly on the Stroop and BIS, with patients performing worse on the Stroop and scoring higher on the BIS. However, there was no association between the Stroop and BIS within the bipolar group. As an exploratory analysis, a positive correlation between Stroop performance and number of episodes was found. Further, we detected a statistical trend in the direction of poorer Stroop performance among patients treated with polypharmacy.

CONCLUSIONS

Both difficulties with behavioral inhibition and self-reported impulsivity were observed to be higher in bipolar patients than controls in the current study. However, within the patient group we did not observe an association between patients' behavioral performance and self-report. This indicates that the parameters likely constitute distinct, dimensional factors of bipolar disorder. In future research, studies with larger samples should investigate which of the two markers constitutes the better marker for the illness and is more suitable to differentiate the most severe patients.

Neurological soft signs and cognitive functions: Amongst euthymic bipolar I disorder cases, non-affected first degree relatives and healthy controls

Both neurological soft signs (NSS) and cognitive deficits are present among euthymic bipolar patients. NSS could be related to neurocognitive performance, but this is not explored thoroughly. Healthy relatives of patients may also suffer from similar deficits. This study compared NSS and cognitive functions in euthymic Bipolar I Disorder (BPI) cases to their non-affected first degree relatives and healthy controls. We also investigated the association between NSS and cognitive functions in these three groups. NSS were assessed in three groups using Neurological Evaluation Scale-revised (NES-r). Eight cognitive domains were assessed in 31 euthymic BPI cases, their 30 non-affected first degree relatives and 30 healthy controls using Computerized Neurocognitive Battery (CNB). Euthymic BPI patients had significantly more NSS than non-affected first degree relatives on 5/7 tests (p-value ranges from 0.042 to p=0.0001) and healthy controls on all tests (p-value from 0.042 to <0.0001). Non-affected first degree relatives and controls did not have any significant difference. BPI participants performed worse than their non-affected first degree relatives on one neurocognitive domain of CNB (spatial memory accuracy, p=0.03) and healthy controls on four domains (spatial memory accuracy (p=0.04), abstraction and mental flexibility efficiency (p=0.04), spatial memory efficiency (p=0.04), and emotion efficiency (p=0.04). Non-affected relatives and healthy controls were similar on neurocognitive domains. Accuracy and efficiency indices of some specific cognitive domains were negatively associated with AV rating and tap copying NSS ratings.

Cognitive function in euthymic bipolar disorder (BP I) patients with a history of psychotic symptoms vs. schizophrenia

Patients with bipolar disorder show cognitive deficits including executive function, which appear to be related to social functioning and outcome. However, subgroups within the spectrum as well as psychopathological features, current mood state/euthymia and disease stage might be confounding factors. We analysed data tests from the Wechsler Intelligence Scale (WIE), verbal fluency (COWA) and trail making tests (TMT-A and TMT-B) obtained in a selected subgroup of currently bipolar I disorder patients, who were currently euthymic and had a history of psychotic symptoms, and compared them to patients with schizophrenia (in remission) and healthy controls, all matched for age, gender, and handedness. Schizophrenia patients showed more severe cognitive impairment, including digit symbol and arithmetic tests, as well as TMT-B (compared to healthy controls), but bipolar patients had stronger impairment on the letter number sequencing test, an indicator of working memory and processing speed. There were no group effects on most verbal fluency tasks (except impairment of schizophrenia patients on one subscale of category fluency). Within the limitations of the study design, our results suggest that even in subgroups of presumably more severely impaired bipolar patients, some cognitive dimensions might achieve remission, possibly related to considerable state effects at testing.

Left temporal activation associated with depression severity during a verbal fluency task in patients with bipolar disorder: a multichannel near-infrared spectroscopy study

BACKGROUND

Neuroimaging studies using multichannel near-infrared spectroscopy (NIRS) have provided compelling evidence about the dysfunction of the frontotemporal cortices in patients with bipolar disorder (BD). However, it remains unclear whether the dysfunction is associated with mood state or symptom severity. Using NIRS, we aimed to clarify differences in oxygenated hemoglobin (oxy-Hb) activation between depressive and euthymic states as well as regional brain dysfunction in relation to symptom severity in BD.

METHODS

Fifty-five patients with BD, including 30 with bipolar depression (BPD) and 25 with euthymic bipolar disorder (BPE), and 28 healthy controls (HCs) participated in the study. Regional hemodynamic changes during a verbal fluency task (VFT) were monitored using a 52-channel NIRS apparatus.

RESULTS

The mean oxy-Hb changes induced by VFT were significantly smaller in the BD patients than in the HCs in 18 channels in the frontotemporal regions (false-discovery rate p<0.05, p=0.000-0.011). The BPD group exhibited significantly smaller changes in mean oxy-Hb compared with the BPE group in three channels of the left temporal region (p=0.005-0.014). In the BD patients, significant negative correlations were observed between mean oxy-Hb changes in the left temporal regions and the severity of depression.

LIMITATIONS

Our sample size was small, making the results susceptible to type II errors.

CONCLUSIONS

BD patients have persistent hypofunction of the frontotemporal cortical regions. Moreover, the hemodynamic response in the left temporal regions is associated with symptom severity.

fMRI evidence for abnormal resting-state functional connectivity in euthymic bipolar patients

BACKGROUND

Neural substrates of bipolar disorder (BD) have frequently been characterized by dysregulation of fronto-limbic networks that may persist during euthymic periods. Only a few studies have investigated euthymic bipolar patients (BP) functional connectivity at rest. The current study aims to assess resting-state functional connectivity in euthymic BP in order to identify trait abnormalities responsible for enduring mood dysregulation in these patients.

METHODS

Medial prefrontal cortex (mPFC) functional connectivity was investigated in 20 euthymic BP and 20 healthy subjects (HS). The functional connectivity maps were compared across groups using a between-group random effect analysis. Additional region of interest (ROI) analysis focused on mPFC-amygdala functional connectivity as well as correlations between the clinical features in euthymic BP was also conducted.

RESULTS

A significant difference between euthymic BP and HS was observed in terms of connectivity between the mPFC and the right dorsolateral prefrontal cortex (dlPFC). A significant negative correlation between the activity of these regions was found in HS but not in euthymic BP. In addition, euthymic BP showed greater connectivity between mPFC and right amygdala compared to HS, which was also correlated with the duration of the disease.

LIMITATIONS

The BP group was heterogeneous with respect to the bipolarity subtype and the medication. The robustness of results could be improved with an increased sample size.

CONCLUSIONS

Compared to HS, the euthymic BP showed abnormal decoupling (decreased functional connectivity) activity between mPFC-dlPFC and hyperconnectivity (increased functional connectivity) and between mPFC and amygdala. These abnormalities could underlie the pathophysiology of BD, and may deteriorate further in accordance with disease duration.

Associations between circadian activity rhythms and functional brain abnormalities among euthymic bipolar patients: a preliminary study

BACKGROUND

Working memory and underlying functional brain deficits have been observed in euthymic bipolar disorder (BD) patients, though there is heterogeneity in the degree of deficits. Sleep/circadian rhythm abnormalities are thought to be a core component of BD and may explain some of the heterogeneity in functional abnormalities. This preliminary study examined associations between sleep/circadian rhythm abnormalities and functional magnetic resonance imaging (fMRI) brain response on a working memory task among BD patients.

METHODS

Fourteen euthymic medicated BD patients wore an actigraph for 7 days before undergoing fMRI with a working memory task. Two matched healthy comparison (HC) groups were used (14 in each sample). One group completed the actigraphy portion and the other completed the fMRI portion of the study. Circadian activity rhythm and sleep variables were calculated and compared between BD and HC participants. Variables that significantly differed were used to examine the association between activity rhythms/sleep abnormalities and fMRI working memory brain response in anatomically defined regions.

RESULTS

Sleep efficiency and the rhythm robustness, mesor, and amplitude-to-width ratio were significantly abnormal in BD patients. Individual variability in all the sleep/circadian variables was significantly associated with the degree of abnormality of brain response in the dorsolateral prefrontal cortex and supramarginal gyri.

LIMITATIONS

Small sample size and multiple comparison groups limit the interpretability of these findings.

CONCLUSIONS

BD patients have abnormal activity rhythms and sleep efficiency, which are associated with abnormal working memory brain response. These preliminary findings support the notion that the sleep/circadian system is important in the functional brain deficits among BD patients.

Cognitive emotion regulation in euthymic bipolar disorder

BACKGROUND

Based on findings indicating increased stress reactivity and prolonged stress recovery in individuals with bipolar disorder (BD), it has been proposed that emotion regulation (ER) deficits lie at the core of this disorder. Recent studies show an increased use of maladaptive ER strategies and a decreased use of adaptive ER strategies in BD. Whether this pattern is merely a correlate of affective episodes or might be a stable characteristic of BD, however, remains to be explored. In addition, it is unclear whether these deficits in ER are specific to people with a history of BD.

METHODS

We examined whether euthymic BD individuals differ from healthy controls (HC) and individuals with a history of Major Depressive Disorder (MDD) with respect to the cognitive ER strategies they habitually use (CERQ) in response to negative affect. The sample consisted of 42 bipolar patients, 43 patients with MDD and 39 HC.

RESULTS

Compared to HC, euthymic BD and MDD individuals reported increased use of rumination, catastrophizing, and self-blame alongside decreased use of positive reappraisal, and putting into perspective. No differences were found between BD and MDD groups.

LIMITATIONS

These findings are based on self-reports reflecting the habitual use of ER-strategies. The use of more objective methods and the examination of the spontaneous use of ER-strategies in euthymic BD would be desirable.

CONCLUSIONS

Deficits in the habitual use of ER strategies may characterize BD and MDD individuals even outside of an acute episode and thereby play a role in the recurrence of affective disorders.

Everyday functional ability across different phases of bipolar disorder

Bipolar Disorder (BD) is a chronic illness characterized by significant neurocognitive impairment and functional deficits. Functional status is typically assessed with self-report or observer ratings restricted by poor participant insight and subjective judgment, while application of performance-based measures has been limited. We assessed functional ability in manic, depressed, and euthymic BD individuals using the UCSD Performance-Based Skills Assessment (UPSA-2), which simulates real-world tasks such as medication management. UPSA-2 was administered to 17 manic or hypomanic BD, 14 depressed BD, 23 euthymic BD, and 28 healthy comparison (HC) participants matched for age, education, and IQ. Psychopathology was quantified with the Young Mania Rating Scale (YMRS), Hamilton Depression Rating Scale (HDRS), and the Positive and Negative Syndrome Scale (PANSS); executive functioning was assessed with the Wisconsin Card Sorting Task (WCST). All BD groups exhibited functional ability deficits on the UPSA-2 and impaired performance on the WCST compared to HC. UPSA-2 scores were lower in manic/hypomanic subjects relative to other BD participants and mania symptoms correlated with functional impairment. Poor WCST performance was also associated with worse UPSA-2 function. In summary, BD functional deficits occur across different phases of the disorder and may be impacted by symptom severity and associated with executive dysfunction.

Inhibitory deficits in euthymic bipolar disorder patients assessed in the human behavioral pattern monitor

BACKGROUND

Bipolar disorder (BD) is associated with inhibitory deficits characterized by a reduced ability to control inappropriate actions or thoughts. While aspects of inhibition such as exaggerated novelty-seeking and perseveration are quantified in rodent exploration of novel environments, similar models are rarely applied in humans. The human Behavioral Pattern Monitor (hBPM), a cross-species exploratory paradigm, has identified a pattern of impaired inhibitory function in manic BD participants, but this phenotype has not been examined across different BD phases. The objective of this study was to determine if euthymic BD individuals demonstrate inhibitory deficits in the hBPM, supporting disinhibition as an endophenotype for the disorder.

METHODS

25 euthymic BD outpatients and 51 healthy comparison subjects were assessed in the hBPM, where activity was recorded by a concealed videocamera and an ambulatory monitoring sensor.

RESULTS

Euthymic BD individuals, similar to manic subjects, demonstrated increased motor activity, greater interaction with novel objects, and more frequent perseverative behavior relative to comparison participants. The quantity of locomotion was also reduced in BD individuals treated with mood stabilizers compared to other patients.

LIMITATIONS

Low sample size for treatment subgroups limits the evaluation of specific medication regimens.

CONCLUSIONS

Our results suggest that BD is distinguished by both trait- and state-dependent inhibitory deficits optimally assessed with sophisticated multivariate measures. These data support the use of the hBPM as a tool to elucidate the effects of BD across various illness states, facilitate the development of BD animal models, and advance our understanding of the neurobiology underlying the disorder.