Impulsivity: present during euthymia in bipolar disorder? - a systematic review

Does Childhood Trauma Predict Impulsive Spending in Later Life? An Analysis of the Mediating Roles of Impulsivity and Emotion Regulation

We sought to investigate whether adverse childhood experiences increase impulsive spending in later life, and whether emotion dysregulation and impulsivity mediate this association. Limited research has examined associations between these factors, and examining the mechanisms involved may inform interventions for impulsive spending. This study used a cross-sectional, correlational design including 189 adult participants who completed an online survey assessing childhood trauma, adverse childhood experiences, impulsive spending, impulsivity, and emotion dysregulation. Greater adverse childhood experiences and childhood trauma were positively correlated with impulsive spending, as well as general impulsivity and emotion dysregulation. Mediation analyses indicated that emotion dysregulation and greater impulsivity accounted for the positive relationship between childhood trauma and impulse spending. Adverse childhood experiences and childhood trauma are associated with increased risk of impulse spending in adulthood via elevated general impulsivity and emotion dysregulation.

Impulsivity and neural correlates of response inhibition in bipolar disorder and their unaffected relatives: A MEG study

BACKGROUND

Response inhibition is a core cognitive impairment in bipolar disorder (BD), leading to increased impulsivity in BD. However, the relationship between the neural mechanisms underlying impaired response inhibition and impulsivity in BD is not yet clear. Individuals who are genetically predisposed to BD give a way of identifying potential endophenotypes.

METHODS

A total of 97 participants, including 39 patients with BD, 22 unaffected relatives (UR) of patients with BD, and 36 healthy controls performed a Go/No-Go task during magnetoencephalography. We carried out time-frequency and connectivity analysis on MEG data.

RESULTS

Decreased beta power, prolonged latency and increased peak frequency in rIFG, decreased beta power in pre-SMA and reduced rIFG-to-pre-SMA connectivity were found in BD relative to healthy controls. In the UR group, we found a decrease in the beta power of pre-SMA and prolonged latency of rIFG. Furthermore, increased motor impulsiveness in BD was related to abnormal alterations in beta oscillatory activity of rIFG and functional connectivity between rIFG and pre-SMA.

CONCLUSIONS

Hypoactivity activity in rIFG and impaired dominant role of rIFG in the prefrontal control network may underlie the neuropathology of response inhibition dysfunction, resulting increased motor impulsivity in BD. Our findings point to measuring rIFG dysfunction as a potential means of identifying individuals at genetic high risk for transition to BD disease expression.

Response inhibition related neural oscillatory patterns show reliable early identification of bipolar from unipolar depression in a Go/No-Go task

BACKGROUND

Response inhibition is a key neurocognitive factor contributing to impulsivity in mood disorders. Here, we explored the common and differential alterations of neural circuits associated with response inhibition in bipolar disorder (BD) and unipolar disorder (UD) and whether the oscillatory signatures can be used as early biomarkers in BD.

METHODS

39 patients with BD, 36 patients with UD, 29 patients initially diagnosed with UD who later underwent diagnostic conversion to BD, and 36 healthy controls performed a Go/No-Go task during MEG scanning. We carried out time-frequency and connectivity analysis on MEG data. Further, we performed machine learning using oscillatory features as input to identify bipolar from unipolar depression at the early clinical stage.

RESULTS

Compared to healthy controls, patients had reduced rIFG-to-pre-SMA connectivity and delayed activity of rIFG. Among patients, lower beta power and higher peak frequency were observed in BD patients than in UD patients. These changes enabled accurate classification between BD and UD with an accuracy of approximately 80 %.

CONCLUSIONS

The inefficiency of the prefrontal control network is a shared mechanism in mood disorders, while the abnormal activity of rIFG is more specific to BD. Neuronal responses during response inhibition could serve as a diagnostic biomarker for BD in early stage.

Emotional urgency predicts bipolar symptoms, severity, and suicide attempt better than non-emotional impulsivity: a cross-sectional study

Introduction

Emotional urgency is an emotion-based subdimension of trait impulsivity that is more clinically relevant to psychopathology and disorders of emotion dysfunction than non-emotional subdimensions (i.e., lack of perseverance, sensation seeking, lack of premeditation). However, few studies have examined the relative effects of emotional urgency in bipolar disorder. This cross-sectional study aimed to establish the clinical relevance of emotional urgency in bipolar disorders by (1) explicating clinically relevant correlates of emotional urgency and (2) comparing its effects against non-emotional impulsivity subdimensions.

Methods and results

A total of 150 individuals with bipolar disorder were recruited between October 2021 and January 2023. Zero-order correlations found that emotional urgency had the greatest effect on bipolar symptoms (r = 0.37 to 0.44). Multiple two-step hierarchical regression models showed that (1) positive urgency predicted past manic symptomology and dysfunction severity (b = 1.94, p < 0.001 and 0.35 p < 0.05, respectively), (2) negative urgency predicted current depression severity, and (3) non-emotional facets of impulsivity had smaller effects on bipolar symptoms and dysfunction by contrast, and were non-significant factors in the final step of all regression models (b < 0.30, ns); Those who had a history of attempted suicide had significantly greater levels of emotional urgency (Cohen's d = -0.63).

Discussion

Notwithstanding the study's limitations, our findings expand status quo knowledge beyond the perennial relationship between non-emotion-based impulsivity and bipolar disorder and its implications.

Clinical assessment of impulsiveness and defence mechanisms in young patients with mood disorders in a two-year prospective study

AIM

There have been limited prospective investigations of early clinical markers involved in mood regulation and diagnosis change in young patients. This study aimed to evaluate the changes in impulsivity and defence mechanisms in patients with major depressive disorder (MDD) and bipolar disorder (BD) with acute symptoms and remission compared to healthy controls (HC), and possible psychological predictors of diagnosis conversion.

METHODS

Seventy-nine young MDD or BD patients and 40 HC were enrolled in a two-year prospective study. A comprehensive clinical interview focused on clinical and psychological evaluation during follow-up visits. The severity of depressive symptoms was evaluated using the Hamilton Depression Rating Scale (HDRS-17), whilst the Young Mania Rating Scale (YMRS) was used for hypo/manic symptoms during each control visit. All patients completed the Defence Style Questionnaire (DSQ-40) and Barratt Impulsiveness Scale (BIS-11).

RESULTS

Patients used more immature defences, and had significantly higher total impulsivity scores than controls. BD patients had elevated motor and non-planning impulsivity compared with HC and MDD subjects. Total and non-planning impulsiveness remained elevated in euthymia in BD and MDD compared to HC. There were no statistically significant differences in total defence styles and impulsiveness scores at baseline vs. euthymia in MDD or BD patients groups. Significantly higher dissociation scores at baseline discriminated depressive patients who convert to BD in their diagnosis.

CONCLUSIONS

Patients with acute mood symptoms used more frequent immature defences and had significantly higher total impulsivity scores than healthy persons. A lack of differences in total defence styles and impulsiveness between patients with acute symptoms and after reaching euthymia in both MDD and BD groups indicates that they are independent of disease status. Dissociation defence mechanisms may be an early diagnostic indicator of BD.

Better than expected: the gap between self-reported and objective measures of cognitive performance in remitted bipolar disorder

Background

Studies comparing objective and self-reported cognitive functioning as well as influencing factors in individuals with remitted bipolar disorder are scarce and contradictory.

Methods

The aim of this study was to compare executive functioning and other objective and self-reported cognitive impairment between 26 individuals with remitted bipolar disorder (15 BD I) and 24 healthy controls using a cross-sectional design. Executive functions were measured by the TAP Go/No-go subtest as well as the Stroop Task. Self-rated functioning was assessed using the Attention Deficit Experience Questionnaire. In addition, possible predictors of self-reported and objective cognitive functioning were examined to perform regression analyses.

Results

Individuals with remitted bipolar disorder did not differ significantly in executive functions or other objective cognitive domains from the healthy control group, but showed a significantly lower level of self-reported cognitive functioning and self-esteem. While self-esteem was the strongest predictor in healthy controls for self-reported cognitive functioning, severity of illness and subthreshold depressive mood were the most important predictors in individuals with remitted bipolar disorder.

Conclusion

The results once again demonstrate the cognitive heterogeneity in bipolar disorder. In the treatment of cognitive deficits, factors such as subthreshold depressive symptomatology and self-esteem should be focused on in addition to cognitive training in remitted patients.

ImGo: A Novel Tool for Behavioral Impulsivity Assessment Based on Go/NoGo Tasks

This manuscript aims to present a novel behavioral impulsivity test ImGo, which is suitable for impulsivity assessment in the general population. A series of three studies was conducted to validate its psychometric qualities. In Study 1 we describe the principles of ImGo and verify its test-retest and split-half reliability and its convergent validity with an impulsivity self-report scale and Stop Signal test. In Study 2 we re-analyze the convergent validity of ImGo with a Stop Signal test and examine the potential relationship between ImGo and oculomotor inhibition measured by an Anti-Saccades test. In Study 3 we present a robust research with a large sample size and investigate the discriminant validity of ImGo with tests of other related cognitive and executive processes. Backed by our findings from these studies we can safely claim ImGo is a powerful tool with a good level of reliability (both test-retest and split-half) and validity (convergent and discriminant). Its potential lies in its use in diagnostic and research practice of experts from various countries as the test has already been translated to 9 languages so far. The open-source Hypothesis platform, on which the ImGo test is running, provides the option of both individual and group testing in laboratory conditions as well as remotely through an internet browser.

Trait-Related Impulsivity, Affective Temperaments and Mood Disorders: Results from a Real-World Multicentric Study

Trait-related impulsiveness is highly prevalent in patients with mood disorders, being associated with negative outcomes. The predictive role of affective temperaments on trait-related impulsivity is still understudied. The aim of the present study is to investigate the relationship between impulsivity and affective temperaments in a sample of euthymic patients with mood disorders. This is a real-world multicentric observational study, carried out at the outpatient units of seven university sites in Italy. All patients filled in the short version of Munster Temperament Evaluation of the Memphis, Pisa, Paris and San Diego and the Barratt Impulsiveness Scale. The study sample included 653 participants, mainly female (58.2%), with a mean age of 46.9 (±14.1). Regression analyses showed that higher levels of trait-related impulsivity were associated to suicide attempts (p < 0.000), the presence of psychotic symptoms during acute phases (p < 0.05), a seasonal pattern (p < 0.05), a lower age at onset of the disorder (p < 0.05), cyclothymic (p < 0.01) and irritable temperaments (p < 0.01). The results of our study highlight the importance to screen patients with mood disorders for impulsivity and affective temperaments in order to identify patients who are more likely to present a worse outcome and to develop personalized and integrated early pharmacological and psychosocial treatment plans. Novelties of the present paper include the recruitment of patients in a stable phase, which reduced possible bias in patients’ self-reports, and the multicentric nature of the study, resulting in the recruitment of a large sample of patients with mood disorders, geographically distributed across Italy, thus improving the generalizability of study results.

The interplay of daily affect and impulsivity measured by mobile surveys in bipolar disorder

Background

Impulsivity is a prominent feature of bipolar disorder associated with various negative sequelae; moreover, it may be a precursor to shifts in affect or mood, but little is known about its association with affect on a day-to-day timescale. Ecological momentary assessments (a method that captures moment-to-moment ratings of psychological states by repeatedly sampling the same individual) of impulsivity and affect using mobile surveys allow for more nuanced examination of mechanisms of mood and behavior dysregulation. However, few existing studies have validated an ecological momentary assessment of impulsivity in bipolar disorder and examined its time-lagged associations with positive and negative affect. 70 participants with bipolar disorder and 102 healthy comparisons participated in an intensive longitudinal study: they underwent 14 days of ecological momentary assessment data collection annually for 1–4 years. Multiple measures of impulsivity and affect were collected using self-report, behavioral, and ecological momentary assessment modalities; these measures were compared, and levels of impulsivity were compared between bipolar disorder and healthy comparison groups. Time-lagged analyses using daily means explored the next-day predictive relationship of impulsivity on positive/negative affect, and vice versa.

Results

The ecological momentary measure of impulsivity was moderately correlated with the self-report but not behavioral impulsivity measure. Bipolar disorder participants evinced higher self-report, behavioral, and daily impulsivity than healthy comparison participants. Time-lagged analyses revealed a bi-directional association between high impulsivity and high next-day negative (but not positive) affect. Post hoc analyses showed that impulsivity specifically predicted next-day anger and anxiety.

Conclusions

Our multimodal assessment of impulsivity allowed for an examination of the day-to-day course of impulsivity and affect, crucial steps toward understanding the mechanisms of mood symptom and episode onset in bipolar disorder.

Suicidal Ideation in Bipolar Disorder: The Relation with Clinical and Sociodemographic Variables

INTRODUCTION

Bipolar disorder (BD) has the highest risk of suicide among all mental disorders. Thus, identifying factors related to suicidal ideation is essential for a better assessment of the risk of suicide in BD.

OBJECTIVE

To analyze the relationship between suicidal ideation and clinical and sociodemographic characteristics in BD patients.

METHOD

This is a cross-sectional study that included eighty individuals with BD. Information regarding sociodemographic data and history of attempted suicide were collected, and the Hamilton Depression Scale, Young Mania Rating Scale, Positive And Negative Syndrome Scale/positive symptom subscale, Clinical Global Impressions Scale for use in bipolar illness, Insight Scale for Affective Disorders, and Barratt Impulsiveness Scale were administered. The presence and severity of suicidal ideation were assessed using the Beck Scale for Suicidal Ideation.

RESULTS

All regression models significantly predicted suicidal ideation. In the model that had the lowest AIC score and the highest cross-validity, the severity of depressive and of manic symptoms (standardized β = 0.49, p < 0.001; standardized β = 0.42, p = 0.007), the insight level (standardized β = - 0.38, p = 0.012) and previous suicide attempt (standardized β = 0.20, p = 0.036) acted as predictors of suicidal ideation, while degree of impulsivity (β standardized = 0.13, p = 0.229) and educational level (standardized β = - 0.16, p = 0.108) did not give a significant contribution.

CONCLUSION

According to our results, more severe depression and mania symptoms, higher level of insight and a history of suicide attempt indicate the occurrence of suicidal ideation in BD.

Rethinking "aggression" and impulsivity in bipolar disorder: Risk, clinical and brain circuitry features

BACKGROUND

Elevated aggression and impulsivity are implicated in Bipolar Disorder (BD); however, relationships between these behavioral constructs have not been clarified, which can lead to misconceptions with negative consequences including stigma and adverse outcomes including suicide. The study aimed to clarify brain-based distinctions between the two constructs and their associations to risk factors, symptoms and suicide thoughts and behaviors.

METHODS

Self-rated Brown-Goodwin Aggression (BGA) and Barratt Impulsiveness Scale (BIS) scores were compared between adults with BD (n = 38, 74% female) and healthy controls (HC, n = 29, 64% female). Relationships were examined between BGA and BIS with childhood trauma questionnaire (CTQ), mood, comorbidities, and magnetic resonance imaging gray matter volume (GMV) assessments.

RESULTS

In BD, BGA and BIS total scores were both elevated and associated with childhood maltreatment (CM), particularly emotional CM, depression, substance use disorders (SUDs) and suicide attempts (SAs). BGA scores were increased by items corresponding to dysregulation of emotional and social behavior and associated with elevated mood states and suicide ideation and GMV decreases in bilateral orbitofrontal cortex and left posterior insula brain regions, previously associated with these behaviors and clinical features. BIS motor impulsiveness scores were associated with GMV decreases in anterior cingulate cortex implicated in mood and behavioral dyscontrol.

LIMITATIONS

modest sample size, self-reports CONCLUSIONS: The findings suggest separable brain-based domains of dysfunction in BD of motor impulsiveness versus emotionally dysregulated feelings that are primarily self-directed. Both domains are associated with suicide behavior and modifiable risk factors of CM, depression and SUDs that could be targeted for prevention.

Long-term outcome predictors after functional remediation in patients with bipolar disorder

BACKGROUND

Improving functioning in patients with bipolar disorder (BD) is one of the main objectives in clinical practice. Of the few psychosocial interventions that have been specifically developed to enhance the psychosocial outcome in BD, functional remediation (FR) is one which has demonstrated efficacy. The aim of this study was to examine which variables could predict improved functional outcome following the FR intervention in a sample of euthymic or subsyndromal patients with BD.

METHODS

A total of 92 euthymic outpatients were included in this longitudinal study, with 62 completers. Partial correlations controlling for the functional outcome at baseline were calculated between demographic, clinical and neurocognitive variables, and functional outcome at endpoint was assessed by means of the Functioning Assessment Short Test scale. Next, a multiple regression analysis was run in order to identify potential predictors of functional outcome at 2-year follow-up, using the variables found to be statistically significant in the correlation analysis and other variables related to functioning as identified in the previous scientific literature.

RESULTS

The regression model revealed that only two independent variables significantly contributed to the model (F(6,53): 4.003; p = 0.002), namely verbal memory and inhibitory control. The model accounted for 31.2% of the variance. No other demographic or clinical variable contributed to the model.

CONCLUSIONS

Results suggest that patients with better cognitive performance at baseline, especially in terms of verbal memory and executive functions, may present better functional outcomes at long term follow-up after receiving functional remediation.

Relationship between impulsivity, comorbid anxiety and neurocognitive functions in bipolar disorder

OBJECTIVE

The aim of the study is to examine the relationship between anxiety and impulsivity and to reveal the correlation of these variables with clinical and sociodemographic features. It is also aimed to investigate the relationship between impulsivity and anxiety with neurocognitive functions in bipolar disorder.

METHODS

The sample of the study comprises of 71 patients with bipolar disorder type I without any comorbidity (BD), 37 patients with anxiety disorder comorbidity with bipolar disorder type I (BDAD), 52 patients with anxiety disorder (AD) and 50 healthy controls (HC). Participants completed Barratt Impulsivity Scale-11, State-Trait Anxiety Inventory 1-2, Panic Disorder Severity Scale (PDSS), brief version of Fear of Negative Evaluation Scale (FNES), Anxiety Sensitivity Index-3 (ASI-3), Trail-Making Test A-B, Digit Span Test, Stroop Test.

RESULTS

PDSS scores, trait anxiety level, hypomanic and mixed episode numbers explain 26% of attention impulsivity. Gender and ASI-3 social dimensions explain 16% of motor impulsivity. Trait anxiety explains non-planning and total impulsivity at 26 and 24%, respectively. When neurocognitive impairment's effect was controlled, it was found AD and BDAD groups had higher impulsivity levels than the BD and HC groups.

CONCLUSION

Anxiety disorder comorbidity increases impulsivity in bipolar disorder.KEYPOINTSIn the presence of anxiety disorder spectrum comorbidity, bipolar disorder patients will have increased impulsivity and the clinical course may be more severe.Trait anxiety levels and anxiety sensitivity may be predictive factors for impulsivity.In the presence of anxiety disorder spectrum comorbidity, it should be taken into consideration that these patients may be more impulsive and should be treated with more care in terms of evaluation of the disorder.

Clustering suicidal phenotypes and genetic associations with brain-derived neurotrophic factor in patients with substance use disorders

Suicide attempts (SA), especially recurrent SA or serious SA, are common in substance use disorders (SUD). However, the genetic component of SA in SUD samples remains unclear. Brain-derived neurotrophic factor (BDNF) alleles and levels have been repeatedly involved in stress-related psychopathology. This investigation uses a within-cases study of BDNF and associated factors in three suicidal phenotypes ('any', 'recurrent', and 'serious') of outpatients seeking treatment for opiate and/or cocaine use disorder. Phenotypic characterization was ascertained using a semi-structured interview. After thorough quality control, 98 SNPs of BDNF and associated factors (the BDNF pathway) were extracted from whole-genome data, leaving 411 patients of Caucasian ancestry, who had reliable data regarding their SA history. Binary and multinomial regression with the three suicidal phenotypes were further performed to adjust for possible confounders, along with hierarchical clustering and compared to controls (N = 2504). Bayesian analyses were conducted to detect pleiotropy across the suicidal phenotypes. Among 154 (37%) ever suicide attempters, 104 (68%) reported at least one serious SA and 96 (57%) two SA or more. The median number of non-tobacco SUDs was three. The BDNF gene remained associated with lifetime SA in SNP-based (rs7934165, rs10835210) and gene-based tests within the clinical sample. rs10835210 clustered with serious SA. Bayesian analysis identified genetic correlation between 'any' and 'serious' SA regarding rs7934165. Despite limitations, 'serious' SA was shown to share both clinical and genetic risk factors of SA-not otherwise specified, suggesting a shared BDNF-related pathophysiology of SA in this population with multiple SUDs.

Altered Risk-Taking Behavior in Early-Stage Bipolar Disorder With a History of Psychosis

Altered risk-taking propensity is an important determinant of functional impairment in bipolar disorder. However, prior studies primarily assessed patients with chronic illness, and risk-taking has not been evaluated in the early illness course. This study investigated risk-taking behavior in 39 euthymic early-stage bipolar disorder patients aged 16-40 years who were treated within 3 years from their first-episode mania with psychotic features and 36 demographically-matched healthy controls using the Balloon Analog Risk Task (BART), a well-validated risk-taking performance-based paradigm requiring participants to make responses for cumulative gain at increasing risk of loss. Relationships of risk-taking indices with symptoms, self-reported impulsivity, cognitive functions, and treatment characteristics were also assessed. Our results showed that patients exhibited significantly lower adjusted scores (i.e., average balloon pumps in unexploded trials) (p = 0.001), lower explosion rate (p = 0.007) and lower cumulative scores (p = 0.003) than controls on BART, indicating their suboptimal risk-taking performance with increased propensity for risk aversion. Risk-taking indices were not correlated with any symptom dimensions, self-reported impulsivity, cognitive functions or antipsychotic dose. No significant difference was observed between patients with and without antipsychotic medications on self-reported impulsivity or any of the BART performance indices. This is the first study to examine risk-taking behavior in early-stage bipolar disorder with history of psychosis and indicates that patients displayed altered risk-taking with increased risk aversion compared with controls. Further research is needed to clarify longitudinal trajectory of risk-taking propensity and its relationships with psychosis and functional outcome in the early stage of bipolar disorder.

Digital Communication Biomarkers of Mood and Diagnosis in Borderline Personality Disorder, Bipolar Disorder, and Healthy Control Populations

Background: Remote monitoring and digital phenotyping harbor potential to aid clinical diagnosis, predict episode course and recognize early signs of mental health crises. Digital communication metrics, such as phone call and short message service (SMS) use may represent novel biomarkers of mood and diagnosis in Bipolar Disorder (BD) and Borderline Personality Disorder (BPD). Materials and Methods: BD (n = 17), BPD (n = 17) and Healthy Control (HC, n = 21) participants used a smartphone application which monitored phone calls and SMS messaging, alongside self-reported mood. Linear mixed-effects regression models were used to assess the association between digital communications and mood symptoms, mood state, trait-impulsivity, diagnosis and the interaction effect between mood and diagnosis. Results: Transdiagnostically, self-rated manic symptoms and manic state were positively associated with total and outgoing call frequency and cumulative total, incoming and outgoing call duration. Manic symptoms were also associated with total and outgoing SMS frequency. Transdiagnostic depressive symptoms were associated with increased mean incoming call duration. For the different diagnostic groups, BD was associated with increased total call frequency and BPD with increased total and outgoing SMS frequency and length compared to HC. Depression in BD, but not BPD, was associated with decreased total and outgoing call frequency, mean total and outgoing call duration and total and outgoing SMS frequency. Finally, trait-impulsivity was positively associated with total call frequency, total and outgoing SMS frequency and cumulative total and outgoing SMS length. Conclusion: These results identify a general increase in phone call and SMS communications associated with self-reported manic symptoms and a diagnosis-moderated decrease in communications associated with depression in BD, but not BPD, participants. These findings may inform the development of clinical tools to aid diagnosis and remote symptom monitoring, as well as informing understanding of differential psychopathologies in BD and BPD.

Impulsivity as a Risk Factor for Suicide in Bipolar Disorder

The accurate assessment of suicide risk in psychiatric, especially affective disorder diagnosed patients, remains a crucial clinical need. In this study, we applied temperament and character inventory (TCI), Barratt impulsiveness scale 11 (BIS-11), PEBL simple reaction time (SRT) test, continuous performance task (CPT), and Iowa gambling task (IGT) to seek for variables linked with attempted suicide in bipolar affective disorder group (n = 60; attempters n = 17). The main findings were: strong correlations between self-report tool scores and objective parameters in CPT; the difference between attempters and non-attempters was found in the number of correctly responded trials in IGT; only one parameter differed between attempters and non-attempters in BPI diagnosis; and no significant differences between suicide attempters and non-attempters in TCI, BIS-11, and SRT were found. These justify the conclusion that impulsivity itself is not a strong predictor, and used as a single variable might not be sufficient to indicate the high suicide risk group among bipolar patients.

Impulsivity, decision-making and risk-taking behaviour in bipolar disorder: a systematic review and meta-analysis

Despite the robust body of work on cognitive aspects of bipolar disorder (BD), a clear profile of associated impairments in impulsivity, decision-making and risk-taking from studies that use behavioural measures has yet to be established. A systematic review, across four electronic databases (PsycINFO, MEDLINE/PubMed, ScienceDirect and Scopus), of literature published between January 1999 and December 2018 was carried out in accordance with the PRISMA statement. The protocol was registered on PROSPERO (CRD42018114684). A fixed-effect and random-effects meta-analysis using the Hedges' g (ES) estimate was performed. The analysis revealed significant impairment in BD individuals with medium effect sizes in various aspects of impulsivity - response inhibition (ES = 0.49; p < 0.0001), delay of gratification (ES = 0.54; p < 0.0001) and inattention (ES = 0.49; p < 0.0001) - and in decision-making (ES = 0.61, p = 0.0002), but no significant impairment in risk-taking behaviour (ES = 0.41; p = 0.0598). Furthermore, we found significant heterogeneity between studies for decision-making and risk-taking behaviour but not for impulsivity. Impaired risk-taking behaviour was significant in a subgroup of BD-I and euthymic individuals (ES = 0.92; p < 0.0001) with no significant heterogeneity. A stratification analysis revealed comparable results in euthymic and non-euthymic individuals for impulsivity. Our findings suggest that behaviour impulsivity is elevated in all phases of BD, representing a core and clinically relevant feature that persists beyond mood symptoms. More studies about decision-making and risk-taking are necessary to establish if they are impaired in BD and to analyze the role of mood state.

Resilience and insight in euthymic patients with bipolar disorder

BACKGROUND

The relationship between resilience and insight may be of potential importance for coping with stress in bipolar disorder (BD). The aim of this study was to investigate if there was a relation between insight and resilience in euthymic patients with BD and also to analyze the associations between resilience, impulsivity, aggression, alcohol use and affective temperament.

METHODS

142 patients with BD type I in remission period were involved. Resilience Scale for Adults-Turkish version, Schedule for Assessment of Insight, Temperament Evaluation of Memphis, Pisa, Paris and San Diego Autoquestionnaire, Barratt Impulsiveness Scale, Buss-Perry Aggression Questionnaire, Michigan Alcoholism Screening Test were used.

RESULTS

Total insight scores were negatively correlated with the scores of perception of future. As distinct from other subscales of resilience, family cohesion had independent significant associations with insight in relabelling of psychotic experiences and attention impulsivity. There was no relationship between total insight and total resilience scores. Resilience scores were negatively correlated with number of depressive episodes and number of suicide attempts. Degree of aggression, degree of impulsivity, scores of depressive and hyperthymic temperament significantly predicted resilience.

LIMITATIONS

Recruitment of patients from a tertiary centre limits the generalizability of the findings.

CONCLUSIONS

Better insight was related to negative perception of the future and did not have significant associations with total resilience. Number of depressive episodes, number of past suicide attempts correlated with resilience, emphasizing the importance of interventions to increase resilience in BD.

Overlapping and distinct neural metabolic patterns related to impulsivity and hypomania in Parkinson's disease

Impulsivity and hypomania are common non-motor features in Parkinson's disease (PD). The aim of this study was to find the overlapping and distinct neural correlates of these symptoms in PD. Symptoms of impulsivity and hypomania were assessed in 24 PD patients using the Barratt Impulsiveness Scale (BIS-11) and Self-Report Manic Inventory (SRMI), respectively. In addition, fluorodeoxyglucose positron emission tomography (FDG-PET) imaging for each individual was performed. We conducted two separate multiple regression analyses for BIS-11 and SRMI scores with FDG-PET data to identify the brain regions that are associated with both impulsivity and hypomania scores, as well as those exclusive to each symptom. Then, seed-based functional connectivity analyses on healthy subjects identified the areas connected to each of the exclusive regions and the overlapping region, used as seeds. We observed a positive association between BIS-11 and SRMI scores and neural metabolism only in the prefrontal areas. Conjunction analysis revealed an overlapping region in the middle frontal gyrus. Regions exclusive to impulsivity were found in the medial part of the right superior frontal gyrus and regions exclusive to hypomania were in the right superior frontal gyrus, right precentral gyrus and right paracentral lobule. Connectivity patterns of seeds exclusively related to impulsivity were different from those for hypomania in healthy brains. These results provide evidence of both overlapping and distinct regions linked with impulsivity and hypomania scores in PD. The exclusive regions for each characteristic are connected to specific intrinsic functional networks.

Impulsivity predicts illness severity in long-term course of bipolar disorder: A prospective approach

BACKGROUND

Bipolar disorder is a common, severe and chronic mental illness. Despite this, predictors of illness severity remain poorly understood. Impulsivity is reported to be associated with bipolar disorder and aggravating comorbidities. This study therefore sought to examine the predictive value of impulsivity for determining illness severity in euthymic bipolar disorder patients.

METHODS

Baseline trait impulsivity of 120 bipolar euthymic patients (81 bipolar disorder I [68%], 80 female [67%]) and 51 healthy controls was assessed using Barratt Impulsiveness Scale 11. The impact of impulsivity on illness severity (measured with morbidity index) was prospectively tested in 97 patients with sufficient follow-up data (average observation time: 54.4 weeks), using linear regression analysis.

RESULTS

Barratt Impulsiveness Scale 11 total (β = 0.01; p < 0.01) and in particular Barratt Impulsiveness Scale 11 attentional subscale scores (β = 0.04; p < 0.001) predicted illness severity in bipolar disorder, while controlling for other clinical variables. Only age at onset persisted as an additional, but less influential predictor. Barratt Impulsiveness Scale 11 total scores and Barratt Impulsiveness Scale 11 attentional subscale scores were significantly higher in euthymic patients compared to controls. This was not observed for the motor or non-planning subscale scores.

LIMITATIONS

The average year-long observation time might not be long enough to account for the chronic course of bipolar disorder.

CONCLUSION

Trait impulsivity and particularly attentional impulsivity in euthymic bipolar patients can be strong predictors of illness severity in bipolar disorder. Future studies should explore impulsivity as a risk assessment for morbidity and as a therapeutic target in bipolar disorder patients.

Developing Dimensional, Pandiagnostic Inhibitory Control Constructs With Self-Report and Neuropsychological Data

Trait markers, or intermediate phenotypes linking different units of analysis (self-report, performance) from the Research Domain Criteria (RDoC) matrix across populations is a necessary step in identifying at-risk individuals. In the current study, 150 healthy controls (HC) and 456 individuals with bipolar disorder (BD) Type I or II, NOS (not otherwise specified) or Schizoaffective BD completed self-report neuropsychological tests of inhibitory control (IC) and executive functioning. Bifactor analyses were used to examine the factor structure of these measures and to evaluate for invariance across groups. Bifactor analyses found modest convergence of items from neuropsychological tests and self-report measures of IC among HC and BD. The factor scores showed evidence of a general IC construct (i.e., subdomain) across measures. Importantly, invariance testing indicated that the same construct was measured equally well across groups. Groups differed on the general factor for three of the four scales. Convergence on a general IC factor and invariance across diagnosis supports the use of combined dimensional measures to identify clinical risk and highlights how prospective RDoC studies might integrate units of analysis.

Prediction of vulnerability to bipolar disorder using multivariate neurocognitive patterns: a pilot study

Bipolar disorder (BD) is a common disorder with high reoccurrence rate in general population. It is critical to have objective biomarkers to identify BD patients at an individual level. Neurocognitive signatures including affective Go/No-go task and Cambridge Gambling task showed the potential to distinguish BD patients from health controls as well as identify individual siblings of BD patients. Moreover, these neurocognitive signatures showed the ability to be replicated at two independent cohorts which indicates the possibility for generalization. Future studies will examine the possibility of combining neurocognitive data with other biological data to develop more accurate signatures.

Are self-rated and behavioural measures of impulsivity in bipolar disorder mainly related to comorbid substance use problems?

INTRODUCTION

Impulsivity is a multidimensional feature observed in bipolar disorder (BD) and substance use disorder (SUD). We previously found a relationship between SUD and risk taking in BD. It is still unclear whether self-rated and behavioral impulsivity measures differ between BD with and without comorbid SUD, or are specific to BD.

METHODS

93 adults with BD with comorbid SUD, 91 BD without SUD, and 93 healthy controls (HC) were administered the Barratt Impulsivity Scale (BIS), the Behavioral Inhibition/Behavioral Activation System Scale (BIS/BAS), and the Cambridge Neuropsychological Test Automated Battery. Analyses compared impulsivity measures across groups controlling for age. Discriminant function analyses (DFA) assessed the combination of variables effectively predicting group membership.

RESULTS

BD displayed increased BIS, BIS/BAS scores, reduced performance on the Cambridge Gambling and Rapid Visual Processing, and Affective Go/No-Go tasks compared to HC. Comparisons between BD with and without SUD showed increased BIS Motor impulsiveness. The overall predictive power of DFA was weak.

CONCLUSIONS

Some facets of impulsivity are a core trait of BD and are partially independent from the presence of SUD. Motor impulsiveness may be distinctive of BD+SUD. More research is needed to understand the role of impulsive behaviors as risk factors for relapse in SUD.

Brexpiprazole reduces hyperactivity, impulsivity, and risk-preference behavior in mice with dopamine transporter knockdown-a model of mania

RATIONALE

Bipolar disorder (BD) is a unique mood disorder defined by periods of depression and mania. The defining diagnosis of BD is the presence of mania/hypomania, with symptoms including hyperactivity and risk-taking. Since current treatments do not ameliorate cognitive deficits such as risky decision-making, and impulsivity that can negatively affect a patient's quality of life, better treatments are needed.

OBJECTIVES

Here, we tested whether acute treatment with brexpiprazole, a serotonin-dopamine activity modulator with partial agonist activity at D_2/3 and 5-HT_1A receptors, would attenuate the BD mania-relevant behaviors of the dopamine transporter (DAT) knockdown mouse model of mania.

METHODS

The effects of brexpiprazole on DAT knockdown and wild-type littermate mice were examined in the behavioral pattern monitor (BPM) and Iowa gambling task (IGT) to quantify activity/exploration and impulsivity/risk-taking behavior respectively.

RESULTS

DAT knockdown mice exhibited hyper-exploratory behavior in the BPM and made fewer safe choices in the IGT. Brexpiprazole attenuated the mania-like hyper-exploratory phenotype and increased safe choices in risk-preferring DAT knockdown mice. Brexpiprazole also reduced safe choices in safe-preferring mice irrespective of genotype. Finally, brexpiprazole reduced premature (impulsive-like) responses in both groups of mice.

CONCLUSIONS

Consistent with earlier reports, DAT knockdown mice exhibited hyper-exploratory, risk-preferring, and impulsive-like profiles consistent with patients with BD mania in these tasks. These behaviors were attenuated after brexpiprazole treatment. These data therefore indicate that brexpiprazole could be a novel treatment for BD mania and/or risk-taking/impulsivity disorders, since it remediates some relevant behavioral abnormalities in this mouse model.

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.

Commonalities in EEG Spectral Power Abnormalities Between Women With ADHD and Women With Bipolar Disorder During Rest and Cognitive Performance

While attention-deficit/hyperactivity disorder (ADHD) and bipolar disorder (BD) denote distinct psychiatric conditions, diagnostic delineation is impeded by considerable symptomatic overlap. Direct comparisons across ADHD and BD on neurophysiological measures are limited. They could inform us on impairments that are specific to or shared between the disorders and, therefore, potential biomarkers that may aid in the identification of the diagnostic boundaries. Our aim was to test whether quantitative EEG (QEEG) identifies differences or similarities between women with ADHD and women with BD during resting-state and task conditions. QEEG activity was directly compared between 20 ADHD, 20 BD and 20 control women during an eyes-open resting-state condition (EO) and a cued continuous performance task (CPT-OX). Both ADHD (t₃₈ = 2.50, p = 0.017) and BD (t₃₈ = 2.54, p = 0.018) participants showed higher absolute theta power during EO than controls. No significant differences emerged between the two clinical groups. While control participants showed a task-related increase in absolute theta power from EO to CPT-OX (t₁₉ = −3.77, p = 0.001), no such change in absolute theta power was observed in the ADHD (t₁₉ = −0.605, p = 0.553) or BD (t₁₉ = 1.82, p = 0.084) groups. Our results provide evidence for commonalities in brain dysfunction between ADHD and BD. Absolute theta power may play a role as a marker of neurobiological processes in both disorders.

Impulsivity predicts the onset of DSM-IV-TR or RDC hypomanic and manic episodes in adolescents and young adults with high or moderate reward sensitivity

BACKGROUND

A growing body of research suggests that bipolar disorders (BD) are associated with high impulsivity. Using a multi-method approach, the current study provided the first examination of the hypothesis that impulsivity would prospectively predict shorter time to onset of DSM-IV-TR or RDC hypomanic or manic episodes in a sample selected based on reward sensitivity, a biobehavioral trait shown to predict onset and course of BD.

METHODS

163 participants with high reward sensitivity and 114 participants with moderate reward sensitivity were followed every six months for an average of 2.68 years. Participants completed the Barratt Impulsiveness Scale - Version 11 (BIS-11), Balloon Analog Risk Task (BART), Beck Depression Inventory, Altman Self-Rating Mania Scale, and an expanded Schedule for Affective Disorders and Schizophrenia (exp-SADS) - Lifetime Version at baseline and were followed prospectively with the exp-SADS - Change Version to assess onset of hypomanic or manic episodes and treatment seeking for mood problems.

RESULTS

Cox proportional hazard regression analyses indicated that impulsivity as measured by a behavioral task (BART; OR=1.04, p=.03) and a self-report measure (BIS-11 Attentional Impulsiveness subscale; OR=1.16, p=.01) predicted shorter time to hypomania/mania onset, after controlling for baseline depressive and manic symptoms, family history of mood disorder, treatment seeking for mood problems, and reward sensitivity.

LIMITATIONS

The study was limited by non-comprehensive assessment of impulsivity and unknown generalizability to clinical samples.

CONCLUSIONS

Impulsivity confers vulnerability to hypomania or mania. Future studies would benefit from considering how impulsivity can be integrated into existing biopsychosocial models of BD.

Response inhibition and interference control in patients with bipolar I disorder and first-degree relatives

OBJECTIVES

The current study aimed to assess both response inhibition (RI) and interference control (IC) in euthymic patients with bipolar disorder (BD-Ps) as well as asymptomatic first-degree relatives (BD-Rs) and healthy controls (HCs) in order to evaluate trait-as opposed to illness-associated features of these components.

METHODS

BD-Ps (n = 35) who had been in the euthymic state for at least six months, BD-Rs (n = 30), and HCs (n = 33) completed a Stop-Signal Task (SST) and Stroop Task to assess RI and IC, respectively. Groups were compared on the stop-signal reaction time (SSRT), stop-signal delay (SSD), mean reaction time on go trials (go-RT), Stroop interference score (S-interference), and number of errors on the color-word-naming trial (S-error). Associations between the patient's clinical features and RI and IC, between the patient's treatment and RI and IC, and between RI and IC in each group were investigated.

RESULTS

BD-Ps and BD-Rs had significantly shorter go-RT and SSD, and longer SSRT compared to HCs, with these scores being similar between the BD-Ps and BD-Rs. Also, both BD-Ps and BD-Rs made significantly more S-errors than HCs, whereas, the S-interference score was not significantly different between groups. There were no significant correlations between Stroop Task and SST scores within each group, nor between clinical features or treatment variables and RI and IC in BD-Ps.

CONCLUSIONS

Overall, impairment in RI and IC (only on S-error score) was present in both patients and relatives. The persistence of these deficits in the absence of mood symptoms suggests that these features may represent candidate endophenotypes for bipolar disorder.

Vulnerability for mania - is it linked to problems delaying gratification?

Impulsivity is described as one of the main risk factors for mania. One facet of impulsivity, the inability to delay gratification, might be of special relevance, because a hypersensitivity to reward is hypothesized to be related to mania. The main aim of this study was to examine whether risk for mania is associated with deficits in the ability to delay gratification using both a behavioral and a self-report (UPPS) measure. An additional reason for choosing the UPPS was to see if prior results about an association between risk for mania and positive urgency could be replicated. Thirty-three individuals at risk for mania and a matched control group were selected using the Hypomanic Personality Scale and interviewed for a history of mood disorders. The main outcome measures were the Single-Key-Impulsivity-Paradigm and Monetary Choice Questionnaire. The groups did not differ in measures of gratification delay but we replicated other studies reporting significantly higher levels of positive urgency and sensation seeking in at-risk individuals. We suggest that individuals at risk might not generally be more impulsive but rather that impulsive behaviors might be triggered in response to specific mood states.

Does a history of substance abuse and illness chronicity predict increased impulsivity in bipolar disorder?

BACKGROUND

Impulsivity is a common feature shared by bipolar disorder (BD) and substance use disorder (SUD). SUD and recurrent mood episodes are considered to be risk factors for poor outcome in BD. However, the association between impulsivity, illness chronicity and SUD in BD remains unexplored.

METHODS

103 BD patients with and without a lifetime history of SUD (36.82±11.34 years, 40 males) were recruited. Participants completed the SCID interview and were administered measures of impulsivity including the Barratt Impulsivity Scale (BIS) and selected tests of the Cambridge Neuropsychological Test Automated Battery (CANTAB). Hierarchical regression analyses explored the relationship between illness chronicity, SUD, and impulsivity.

RESULTS

Variance in the BIS, number of false alarms on the Rapid Visual Processing task and other impulsivity indicators of the Cambridge Gambling Task (CGT) was not explained by the chosen variables. Only an increased number of commission errors in the negative condition of the Affective Go/No Go task was significantly associated with illness chronicity. Furthermore there was a trend suggesting a relationship between a lifetime history of SUD and increased propensity to risk-taking during the CGT.

LIMITATIONS

Potential limitations include medication and patients׳ remission status from SUD.

CONCLUSIONS

Contrary to our expectations impulsivity was generally not predicted by indicators of illness chronicity or SUD. While impulsivity could still be a marker of BD that is present before the onset of the disorder, the link between the number of mood episodes and specific indicators of impulsivity may be related to mechanisms of neuroprogression.