Increased trait-like impulsivity and course of illness in bipolar disorder

Resilience and impulsivity in euthymic patients with bipolar disorder

BACKGROUND

Stress plays an important role in the onset and recurrence of bipolar disorder (BD). Resilience is the ability to cope with stress or adversity. Few studies have examined resilience in BD, and this study aimed to investigate the clinical correlates of resilience in euthymic patients with BD.

METHODS

A total of 62 outpatients with BD type I, II, and not otherwise specified (NOS) who were in remission and 62 healthy individuals matched with the BD group in terms of age and sex were recruited. All participants completed the Connor-Davidson Resilience Scale and Barratt Impulsiveness Scale. A psychiatrist interviewed the subjects to assess clinical characteristics. Multiple linear regression analysis was used to determine factors associated with resilience.

RESULTS

The BD group had significantly higher levels of impulsivity and lower levels of resilience compared with the control group. Degree of impulsivity, number of depressive episodes, Clinical Global Impression (CGI) scores, and length of education were significantly correlated with resilience. Attention impulsivity, non-planning impulsivity, and number of depressive episodes were associated with low levels of resilience, even when age, sex, length of education, and CGI scores were controlled.

LIMITATIONS

Because tertiary hospital patients were recruited, the generalizability of the findings is limited.

CONCLUSIONS

This study shows that low levels of resilience are related to high levels of impulsivity and to an increased number of depressive episodes in euthymic patients with BD. Given the reciprocal relationship between resilience and impulsivity, efforts to enhance resilience and reduce impulsivity may make important contributions to the treatment of patients with BD.

Trait impulsivity and increased pre-attentional sensitivity to intense stimuli in bipolar disorder and controls

Impulsivity and sensation seeking are stimulus-oriented traits. Because they differ in degree of intention and planning, they may have distinct neurophysiological mechanisms. Impulsivity is prominent in bipolar disorder, and may be related to pre-attentional information filtering and stimulus-orientation. We investigated specificity of relationships between impulsivity and sensitivity to stimulus intensity in bipolar disorder and controls, using intensity-sensitivity of auditory evoked potentials. Seventy-six subjects (37 healthy controls, 39 with bipolar disorder) were administered an intensity-sensitivity paradigm. Additional measures included Barratt Impulsiveness Scale (BIS-11) and Eysenck Impulsivity and Venturesomeness scores. State-dependent rapid-response impulsivity was measured using the Immediate Memory Task. Intensity-sensitivities of the auditory evoked P1N1, N1P2, P1, N1, and P2 potentials were assessed as the slope of amplitude relative to loudness. Analyses used general linear models (GLM) with impulsivity-related measures as dependent variables and age, gender, education, and diagnosis as dependent variables. BIS-11 total, motor, and attentional impulsivity scores correlated positively with pre-attentional N1 and P1N1 intensity-sensitivity slopes in bipolar disorder, but not in controls. BIS-11 nonplanning and Eysenck Venturesomeness scores did not correlate with intensity-sensitivity. Intensity-sensitivity slopes did not correlate with rapid-response impulsivity. Correlations between N1 or P1N1 slopes and BIS-11 scores in bipolar disorder were not affected by age, education, WAIS, treatment, symptoms, or gender. Trait impulsivity in bipolar disorder may be related to poorly modulated stimulus-driven late pre-attentional responses to stimuli, potentially resulting in exaggerated responses to intense stimuli even before conscious awareness. Components of trait impulsivity are physiologically heterogenous relative to intensity-sensitivity.

Different impulsivity profiles in borderline personality disorder and bipolar II disorder

INTRODUCTION

Borderline personality disorder (BPD) and bipolar II disorder (BP II) share clinical characteristics including impulsivity. Their relationship is disputed. In this study, we investigated self-reported impulsivity in these patient groups and in a healthy control group. Effects of current mood state and of traumatic childhood experiences were explored.

METHODS

Twenty-five patients with BPD without comorbid bipolar disorder; 20 patients with BP II without comorbid BPD; and 44 healthy control subjects completed the UPPS questionnaire which yields assessments of four components of impulsivity: Urgency, Lack of Premeditation, Lack of Perseverance, and Sensation Seeking. Current mood state was rated using the Montgomery Asberg Depression Rating Scale (MADRS), and the Young Mania Rating Scale (YMRS). Traumatic childhood experiences were assessed using the Childhood Trauma Questionnaire (CTQ). Group differences in UPPS levels; and effects of mood state and CTQ score on UPPS scores in patients were investigated.

RESULTS

BPD patients showed significantly higher levels of Urgency and Lack of Perseverance than BP II patients and controls, and a significantly higher level of Lack of Premeditation than controls. BP II patients showed higher levels of Urgency and Lack of Perseverance than controls. In BP II, higher MADRS scores were associated with higher impulsivity scores. Also, higher CTQ scores were associated with higher Urgency scores in BP II.

LIMITATIONS

Relatively small sample size; cross-sectional assessment of influence of mood state.

CONCLUSIONS

BPD patients exhibited markedly elevated UPPS impulsivity scores compared with healthy controls and BP II patients, and the elevations were not related to current mood state. BP II patients showed moderately elevated impulsivity scores which were associated with a depressed mood state and to some extent with a history of childhood trauma. The findings suggest that BPD and BP II have different impulsivity profiles.

"Latent" infection with Toxoplasma gondii: association with trait aggression and impulsivity in healthy adults

BACKGROUND

Latent chronic infection with Toxoplasma gondii (T. gondii), a common neurotropic pathogen, has been previously linked with suicidal self-directed violence (SSDV). We sought to determine if latent infection with T. gondii is associated with trait aggression and impulsivity, intermediate phenotypes for suicidal behavior, in psychiatrically healthy adults.

METHODS

Traits of aggression and impulsivity were analyzed in relationship to IgG antibody seropositivity for T. gondii and two other latent neurotropic infections, herpes simplex virus 1 (HSV1) and cytomegalovirus (CMV). One thousand community-residing adults residing in the Munich metropolitan area with no Axis I or II conditions by SCID for DSM-IV (510 men, 490 women, mean age 53.6 ± 15.8, range 20-74). Plasma samples were tested for IgG antibodies to T. gondii, HSV-1 and CMV by ELISA. Self-reported ratings of trait aggression scores (Questionnaire for Measuring Factors of Aggression [FAF]) and trait impulsivity (Sensation-Seeking Scale-V [SSS-V]) were analyzed using linear multivariate methods.

RESULTS

T. gondii IgG seropositivity was significantly associated with higher trait reactive aggression scores among women (p < .01), but not among men. T. gondii-positivity was also associated with higher impulsive sensation-seeking (SSS-V Disinhibition) among younger men (p < .01) aged 20-59 years old (median age = 60). All associations with HSV-1 and CMV were not significant.

CONCLUSIONS

Aggression and impulsivity, personality traits considered as endophenotypes for SSDV, are associated with latent T. gondii infection in a gender and age-specific manner, and could be further investigated as prognostic and treatment targets in T. gondii-positive individuals at risk for SSDV.

Illness-course modulates suicidality-related prefrontal gray matter reduction in women with bipolar disorder

OBJECTIVE

Explore interrelationships between suicide attempt history (Objective 1) or suicide attempt severity (Objective 2) with prefrontal cortex gray matter (PFCGM ) volume and illness-course in patients with bipolar disorder (BD).

METHOD

Ninety-three women with BD-I or -II diagnosis (51 with and 42 without suicide attempt history) underwent structural MRI and filled out questionnaires. Measured were GM volumes of 11 PFC regions, BD illness-course, and attempt history and severity. Effects were examined with repeated measures GLM or logit analyses.

RESULTS

Objective 1: Attempt history was associated with increased trait impulsivity and aggression, and higher prevalence of BD-I, past drug use disorder, and past psychiatric hospitalization. PFCGM volume was lower in patients with than without attempt history in those with past psychiatric hospitalization. PFCGM volume was higher in patients with than without attempt history in those without hospitalization. Higher trait aggression predicted attempt history. Objective 2: Increased frontal pole volume and younger age at first hospitalization predicted many suicide attempts.

CONCLUSION

Attempt history in patients with BD related to PFCGM volume reduction or increase. Volume modulation by psychiatric hospitalization could reflect effects of illness-course or care. Attempt severity was not related to volume reduction. Research on suicidality-brain relationships should include illness-course and attempt severity measures.

Reward processing in healthy offspring of parents with bipolar disorder

IMPORTANCE

Bipolar disorder (BD) is highly familial and characterized by deficits in reward processing. It is not known, however, whether these deficits precede illness onset or are a consequence of the disorder.

OBJECTIVE

To determine whether anomalous neural processing of reward characterizes children at familial risk for BD in the absence of a personal history of a psychopathologic disorder.

DESIGN, SETTING, AND PARTICIPANTS

This study compared neural activity and behaviors of children at high and low risk for mania while they anticipate and respond to reward and loss. The study was performed from September 15, 2009, through February 17, 2012, in a university functional magnetic resonance imaging facility and included 8- to 15-year-old children without disorders born to a parent with BD (n = 20 high-risk children) and demographically matched healthy comparison children (n = 25 low-risk children).

MAIN OUTCOMES AND MEASURES

Neural activity, as measured with functional magnetic resonance imaging, during anticipation and receipt of reward and loss during a monetary incentive delay task.

RESULTS

While anticipating losses, high-risk children had less activation in the pregenual cingulate than did their low-risk counterparts (t19 = -2.44, P = .02). When receiving rewards, high-risk children had greater activation in the left lateral orbitofrontal cortex than did low-risk children (t43 = -3.04, P = .004). High-risk children also had weaker functional connectivity between the pregenual cingulate and the right ventrolateral prefrontal cortex while anticipating rewards than did low-risk children (t19 = -4.38, P < .001) but had a stronger connectivity between these regions while anticipating losses (t24 = 2.76, P = .01). Finally, in high- but not low-risk children, novelty seeking was associated with increased striatal and amygdalar activation in the anticipation of losses, and impulsivity was associated with increased striatal and insula activation in the receipt of rewards.

CONCLUSIONS AND RELEVANCE

Aberrant prefrontal activations and connectivities during reward processing suggest mechanisms that underlie early vulnerabilities for developing dysfunctional regulation of goal pursuit and motivation in children at high risk for mania. Longitudinal studies are needed to examine whether these patterns of neural activation predict the onset of mania and other mood disorders in high-risk children.

Lipid correlates of attentional impulsivity in first episode mania: results from an Indian population

BACKGROUND

Attentional/cognitive impulsivity has been demonstrated as being associated with an increased risk for suicide and other self-harming behaviors, along with a more severe course in patients with bipolar disorder. That an alteration of the various serum lipid fractions might be associated with increased impulsivity has been proposed in the past, but evidences are ambiguous and mainly based on western population data.

OBJECTIVE

The present study was aimed to analyze the attentional impulsivity and various serum lipid fractions in bipolar patients, from an Indian perspective.

MATERIALS AND METHODS

At presentation, 60 drug free/naïve first episode Mania patients were rated on the Barratt impulsiveness scale-version 11 and Young Mania Rating Scale; body mass index (BMI) was calculated and blood samples were analyzed for total cholesterol (TC), high density lipoproteins, low density lipoproteins and very low density lipoproteins (VLDL), triglycerides (TG) and apolipoproteins A1 and B.

RESULTS

The analysis revealed statistically significant negative correlation and inverse linear relationship between TC, TG, VLDL and BMI with attentional impulsivity.

CONCLUSION

The present study adds to the growing literature on a complex relationship between lipid fractions and attentional impulsivity. The findings present interesting insights into the possible substrates of human behavior at biochemical levels. The implications are many, including a need to introspect regarding the promotion of weight loss and cholesterol reduction programs in constitutionally vulnerable population.

Shared clinical associations between obesity and impulsivity in rapid cycling bipolar disorder: a systematic review

BACKGROUND

Obesity seems to show a two-way relationship with bipolar disorder (BD), representing not only a possible vulnerability factor but also a consequence of chronic mood dysregulation associated with an overall poor prognosis. Increased impulsivity has been described across all stages and phases of BD as being also associated with a worse prognosis. Although obesity and impulsivity are common features among rapid cycling bipolar disorder (RC-BD) patients, there is a lack of understanding about the clinical implications of these conditions combined in BD.

METHODS

To explore and integrate available evidence on shared clinical associations between obesity and impulsivity in RC-BD a systematic search of the literature in the electronic database of the National Library of Medicine (PubMed) has been conducted.

RESULTS

One hundred and fourteen articles were included in our systematic review. Among RC-BD patients, substance abuse disorders (SUDs), anxiety disorders (ADs), predominantly depressive polarity, chronic exposure to antidepressants, psychotic symptoms, suicidality, and comorbid medical conditions are strongly associated with both obesity and impulsivity.

LIMITATIONS

Heterogeneity of published data, inconsistent measurements of both obesity and impulsivity in RC-BD and an absence of control for RC-BD in epidemiological surveys. Consequently, their combined impact on the severity of RC-BD is yet to be recognized and remains to be poorly understood.

CONCLUSION

In RC-BD patients the co-occurrence of obesity and impulsivity is associated with an unfavorable course of illness, specific shared clinical correlates, negative psychosocial impact, and overall worse prognosis. There is a need to examine obesity and impulsivity as modulating factors and markers of severity in RC-BD.

Simple Measures of Hopelessness and Impulsivity are Associated with Acute Suicidal Ideation and Attempts in Patients in Psychiatric Crisis

OBJECTIVE

To explore the authors' predictions 1) that hopelessness would positively correlate with suicidal ideation and that impulsivity (either transient urges to self-harm or impulsive acting out) would positively correlate with suicidal behavior, and 2) that the recent or long-standing nature of the traits will have corresponding effects on reported histories of suicidal ideation and behavior.

DESIGN

Questionnaire validation trial in which each subject received every measure in counterbalanced fashion.

SETTING

Inpatient and outpatient psychiatric settings associated with a medium-sized medical school in the southeastern United States.

PARTICIPANTS

Forty-five subjects presenting with varying levels of suicidal ideation and behavior completed measures providing information about their histories of suicidal ideation and behavior, recent feelings of hopelessness, feelings of general hopelessness, recent feelings of difficulty controlling urges to self-harm, and feeling about general levels of impulsivity.

MEASUREMENTS

The InterSePT Scale for Suicidal Thinking-Plus, the Sheehan-Suicidality Tracking Scale, the Columbia-Suicide Severity Rating Scale, and six additional questions to assess hopelessness and impulsivity.

RESULTS

Recent and trait hopelessness correlated positively with suicidal ideation. Patients who reported any suicide attempt endorsed higher levels of general impulsivity than those who did not report a history of at least one suicide attempt. Those enrolled in the study secondary to a very recent suicide attempt reported more difficulties with recent suicidal impulses.

CONCLUSION

Simple measures of hopelessness and impulsivity are associated with suicidal ideation and attempts and may add to determination of suicide risk.

Decision-making and trait impulsivity in bipolar disorder are associated with reduced prefrontal regulation of striatal reward valuation

Bipolar disorder is characterized by impaired decision-making captured in impulsivity and risk-taking. We sought to determine whether this is driven by a failure to effectively weight the lower-order goal of obtaining a strongly desired reward in relation to higher-order goals, and how this relates to trait impulsivity and risk-taking. We hypothesized that in bipolar disorder the weighting of valuation signals converging on ventromedial prefrontal cortex are more heavily weighted towards ventral striatum inputs (lower-order), with less weighting of dorsolateral prefrontal cortex inputs (higher-order). Twenty euthymic patients with bipolar disorder not in receipt of antipsychotic medication and 20 case-matched controls performed a roulette task during functional magnetic resonance imaging. Activity in response to high-probability ('safe') and low-probability ('risky') prospects was measured during both anticipation, and outcome. In control subjects, anticipatory and outcome-locked activity in dorsolateral prefrontal cortex was greater for safe than risky reward prospects. The bipolar disorder group showed the opposite pattern with preferential response to risky rewards. This group also showed increased anticipatory and outcome-locked activity in ventral striatum in response to rewards. In control subjects, however, ventromedial prefrontal activation was positively associated with both ventral striatum and dorsolateral prefrontal activity; patients evidenced a strong positive association with ventral striatum, but a negative association with dorsolateral prefrontal cortex. Response to high-probability rewards in dorsolateral prefrontal cortex was inversely associated with trait impulsivity and risk-taking in the bipolar disorder group. Our findings suggest that clinically impulsive and risky decision-making are related to subjective valuation that is biased towards lower-order preference, with diminished integration of higher-order goals. The findings extend a functional neuroanatomical account of disorders characterized by clinically impulsive decision-making, and provide targets for evaluating interventions that foster self-control.

Disturbed anterior prefrontal control of the mesolimbic reward system and increased impulsivity in bipolar disorder

Bipolar disorder (BD) is characterized by recurrent mood episodes ranging from severe depression to acute full-blown mania. Both states of this severe psychiatric disorder have been associated with alterations of reward processing in the brain. Here, we present results of a functional magnetic resonance imaging (fMRI) study on the neural correlates and functional interactions underlying reward gain processing and reward dismissal in favor of a long-term goal in bipolar patients. Sixteen medicated patients diagnosed with bipolar I disorder, euthymic to mildly depressed, and sixteen matched healthy controls performed the 'desire-reason dilemma' (DRD) paradigm demanding rejection of priorly conditioned reward stimuli to successfully pursue a superordinate goal. Both groups exhibited significant activations in reward-related brain regions, particularly in the mesolimbic reward system. However, bipolar patients showed reduced neural responses of the ventral striatum (vStr) when exploiting a reward stimulus, and exhibited a decreased suppression of the reward-related activation of the mesolimbic reward system while having to reject immediate reward in favor of the long-term goal. Further, functional interaction between the anteroventral prefrontal cortex and the vStr in the 'DRD' was significantly impaired in the bipolar group. These findings provide evidence for a reduced responsivity of the vStr to reward stimuli in BD, possibly related to clinical features like anhedonia. The disturbed top-down control of mesolimbic reward signals by prefrontal brain regions in BD can be interpreted in terms of a disease-related enhanced impulsivity, a trait marker of BD.

Association between family history of mood disorders and clinical characteristics of bipolar disorder: results from the Brazilian bipolar research network

OBJECTIVES

To compare clinical characteristics of bipolar disorder (BD) in patients with and without a family history of mood disorders (FHMD) in a large sample from the Brazilian Research Network of Bipolar Disorders.

METHODS

Four-hundred eighty-eight DSM-IV BD patients participating in the Brazilian Research Network of Bipolar Disorders were included. Participants were divided between those with FHMD (n=230) and without FHMD (n=258). We compared these two groups on demographic and clinical variables and performed a logistic regression to identify which variables were most strongly associated with positive family history of mood disorders.

RESULTS

BD patients with FHMD presented with significantly higher lifetime prevalence of any anxiety disorder, obsessive-compulsive disorder, social phobia, substance abuse, and were more likely to present history of suicide attempts, family history of suicide attempts and suicide, and more psychiatric hospitalizations than BD patients without FHMD. Logistic regression showed that the variables most strongly associated with a positive FHMD were any comorbid anxiety disorder, comorbid substance abuse, and family history of suicide.

LIMITATIONS

Cross-sectional study and verification of FHMD by indirect information.

CONCLUSION

BD patients with FHMD differ from BD patients without FHMD in rates of comorbid anxiety disorder and substance abuse, number of hospitalizations and suicide attempts. As FHMD is routinely assessed in clinical practice, these findings may help to identify patients at risk for particular manifestations of BD and may point to a common, genetically determined neurobiological substrate that increases the risk of conditions such as comorbidities and suicidality in BD patients.

The relationship between impulsivity and lipid levels in bipolar patients: does temperament explain it?

BACKGROUND

The aim of this study was to investigate whether there was a relationship between impulsivity and lipid levels in patients with bipolar disorder (BD) and to examine the correlation of impulsivity and lipid levels with temperament subtypes.

METHODS

For this purpose, one hundred patients who were admitted to our out-patient unit for routine controls, had been in remission for at least 8weeks, and diagnosed as BD according to the DSM-IV were evaluated consecutively. Impulsivity and temperament were evaluated with the BIS-11 and the TEMPS-A. Blood samples were obtained to measure levels of lipids (cholesterol, triglyceride, high density lipoprotein-HDL, low density lipoprotein-LDL).

RESULTS

A weak correlation was found between impulsivity scores and triglyceride levels (r=0.190, p=0.050). Correlation was found between impulsivity scores and depressive, anxious, cyclothymic, and irritable temperaments (r=0.371, p<0.001; r=0.458, p<0.001; r=0.541, p<0.001; r=0.530, p<0.001), while triglyceride levels were only related with depressive and anxious temperaments (r=0.485, p=0.001 and r=0.391, p=0.006).

CONCLUSIONS

Temperament is an important mediator of the relationship between lipid levels and trait impulsivity in patients with BD.

Association between GSK3β gene and increased impulsivity in bipolar disorder

Bipolar patients present increased levels of impulsivity even during remission periods. It is known that this dimensional trait negatively impacts on the course of illness and worsens their prognosis and outcome. Evidence from both basic and clinical researches supports that Lithium (Li) may decrease impulsivity. Owing to the fact that Li inhibits both glycogen synthetase kinase-3 (GSK3) isoenzimes, our aim was to analyze the potential impact of genetic variants located at the GSK3 α and β genes on impulsivity levels in a bipolar sample. Our sample consisted of 199 unrelated Caucasian bipolar outpatients who were recruited from the Bipolar Disorder Unit of the Hospital Clinic of Barcelona and from primary care settings from Oviedo. Four polymorphisms at the GSK3 α and β genes were genotyped in order to analyze the impact of genetic variability on impulsivity as measured by the BIS-11 scale. Single SNP analysis showed that patients carrying T and G alleles at the rs1732170-GSK3β and the rs334558-GSK3β, respectively, presented increased levels of attentional impulsivity compared to non-carriers. These results were also confirmed by haplotype analysis. Our results suggest that genetic variability at GSK3β gene is associated to increased impulsivity in bipolar patients.

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

Because impulsivity is part of the presentation of bipolar disorder (BD) and is associated with its course, this systematic review presents the evidence whether increased impulsivity is present in a stable, euthymic mood and therefore potentially a vulnerability marker for BD. A multi-faceted model of impulsivity was adopted to explore how different facets may relate differently to BD. The evidence was explored in relation to studies employing measures of trait impulsivity (in self-report format) and studies exploring impulsivity with behavioural paradigms. Behavioural paradigms were separated into studies measuring response inhibition and those measuring the ability to delay gratification. Twenty-three papers met the inclusion criteria. Most studies using self-report measures found significant differences between euthymic BD patients and healthy controls. There was little evidence of increased impulsivity as measured by behavioural paradigms. Most studies found no significant difference in response inhibition between groups, though it is possible that much of the literature in this area was underpowered to detect an effect. Only five studies explored delay of gratification, of which the two methodologically strongest studies found no group differences. In conclusion, there is evidence that euthymic patients with BD report increased impulsivity when using self-ratings. However, there is currently limited evidence of impulsivity on behavioural measures assessing response inhibition, and this might be restricted to more severe cases. More research is needed on the ability to delay gratification before drawing any conclusions. However, to establish facets of impulsivity as vulnerability markers, future studies should include at-risk individuals to evaluate whether self-rated or behavioural impulsivity precedes the onset of BD.

A profile approach to impulsivity in bipolar disorder: the key role of strong emotions

OBJECTIVE

Bipolar disorder has been associated with elevated impulsivity - a complex construct subsuming multiple facets. We aimed to compare specific facets of impulsivity in bipolar disorder, including those related to key psychological correlates of the illness: reward sensitivity and strong emotion.

METHOD

Ninety-one individuals diagnosed with bipolar I disorder (inter-episode period) and 80 controls completed several well-validated impulsivity measures, including those relevant to reward (Fun-seeking subscale of the Behavioral Activation System scale) and emotion (Positive Urgency and Negative Urgency scales).

RESULTS

Bipolar participants reported higher impulsivity scores than did controls on all of the impulsivity measures, except the Fun-seeking subscale of the Behavioral Activation System scale. Positive Urgency - a measure assessing the tendency to act impulsively when experiencing strong positive emotion - yielded the largest group differences: F(1,170) = 78.69, P < 0.001, partial η(2)  = 0.316. Positive Urgency was also associated with poorer psychosocial functioning in the bipolar group: ΔR(2)  = 0.24, b = -0.45, P < 0.001.

CONCLUSION

Individuals with bipolar I disorder appear to be at particular risk of behaving impulsively when experiencing strong positive emotions. Findings provide an important first step toward developing a more refined understanding of impulsivity in bipolar disorder with the potential to inform targeted interventions.

Reward sensitivity and anger in euthymic bipolar disorder

According to the hypersensitive behavioral approach system (BAS) model of bipolar disorder (BP), hypersensitivity of the BAS is a trait that should be present even in the euthymic state. This would be expected to result in increased anger and reward sensitivity, both of which are related to the approach system. This study examined these predictions through the use of tasks that assess different aspects of the BAS: reward sensitivity, anger and impulsivity. These characteristics were assessed using the probabilistic classification task (PCT), ultimatum game (UG) and single key impulsivity paradigm (SKIP), respectively. Participants were euthymic adult bipolar disorder patients (BP; N=40) and healthy controls (HC; N=41). In the UG, all participants showed the standard pattern of rejecting overtly unfair offers and accepting clearly fair offers; however, BPs rejected more of the moderately unfair offers than did HCs. BP and HC participants did not differ on their ability to learn, but did show different patterns of learning from reward and punishment. Learning for reward and punishment were negatively correlated in the BP group, suggesting that individuals could learn well either from reward or punishment, but not both. No correlation was found between these forms of learning in the HC group. BP patients show signs of their disorder even in the euthymic state, as seen by the dysbalance between reward and punishment learning and their residual anger in the UG.

Overgenerality memory style for past and future events and emotions related in bipolar disorder. What are the links with problem solving and interpersonal relationships?

This study investigated patients with Bipolar Disorder's abilities to generate specific past and future events in response to positive and negative cues words as well as emotional intensity related to these ones. The relationships between the number of generated specific events cognitive functioning, interpersonal problems and the ability to problem solving were investigated. Nineteen BD and nineteen healthy controls completed a French version of the AMT to evaluate the past and future events recall, in function of their valence, and emotions related. Furthermore, they completed the Optional Thinking Test, the Inventory of Interpersonal Problems and the neuropsychological measures. Compared to healthy controls, BD recollected (1) fewer specific past negative events and (2) fewer future specific positive and negative events furthermore, (3) they felt more emotional intensity related to future events. These results were explained in the light of theoretical models. Finally, specific past memories deficits in BD were linked with issues in problem solving but not with levels of distress arising from interpersonal problems. In view of AM functions in everyday life, all types of deficits should be taken into consideration, and AM remediation envisaged.

Pre-attentive information processing and impulsivity in bipolar disorder

Early responses to stimuli can be measured by sensory evoked potentials (EP) using repeated identical stimuli, S1 and S2. Response to S1 may represent efficient stimulus detection, while suppression of response to S2 may represent inhibition. Early responses to stimuli may be related to impulsivity. We compared EP reflecting stimulus detection and inhibition in bipolar disorder and healthy controls, and investigated relationships to impulsivity. Subjects were 48 healthy controls without family histories of mood disorder and 48 with bipolar disorder. EP were measured as latencies and amplitudes for auditory P50 (pre-attentional), N100 (initial direction of attention) and P200 (initial conscious awareness), using a paired-click paradigm, with identical stimuli 0.5 s apart. Impulsivity was measured by questionnaire and by laboratory tests for inability to suppress responses to stimuli or to delay response for a reward. Analyses used general linear models. S1 amplitudes for P50, N100, and P200, and gating of N100 and P200, were lower in bipolar disorder than in controls. P50 S1 amplitude correlated with accurate laboratory-task responding, and S2 amplitude correlated with impulsive task performance and fast reaction times, in bipolar disorder. N100 and P200 EP did not correlate with impulsivity. These findings were independent of symptoms, treatment, or substance-use history. EPs were not related to questionnaire-measured or reward-based impulsivity. Bipolar I disorder is characterized by reduced pre-attentional and early attentional stimulus registration relative to controls. Within bipolar disorder, rapid-response impulsivity correlates with impaired pre-attentional response suppression. These results imply specific relationships between ERP-measured response inhibition and rapid-response impulsivity.

A sib-pair analysis of impulsivity in bipolar disorder type I

OBJECTIVE

The aim of this study was to compare impulsivity among patients with bipolar disorder, their siblings, and healthy controls in order to examine whether impulsivity in bipolar disorder is related to genetic liability for the illness.

METHODS

Using the Barratt Impulsiveness Scale, we assessed 204 subjects: 67 euthymic outpatients with bipolar disorder type I, 67 siblings without bipolar disorder, and 70 healthy controls.

RESULTS

Impulsivity scores were higher among patients with bipolar disorder than among healthy controls. Siblings showed higher motor impulsivity scores than did healthy controls.

CONCLUSIONS

Our results suggest that motor impulsivity may be a vulnerability marker for bipolar disorder. Our data may contribute to further improve preventive strategies in subjects at high risk for bipolar disorder.

Familial transmission of parental mood disorders: unipolar and bipolar disorders in offspring

OBJECTIVES

Offspring of depressed parents are at increased risk for psychiatric disorders. Although bipolar disorder (BD) and major depressive disorder (MDD) are both found in the same families, it is not clear whether transmission to offspring of BD or MDD tends to occur from parents with the same mood disorder subtype. Our primary hypothesis was that the offspring of parents with BD would be at increased risk for BD and other comorbid disorders common to BD, such as anxiety and substance use, relative to the offspring of parents with MDD. The offspring of parents with BD versus those with MDD were also hypothesized to be at greater risk for externalizing disorders (i.e., conduct disorder, attention-deficit hyperactivity disorder, or antisocial personality disorder).

METHODS

Parents (n = 320) with mood disorders and their offspring (n = 679) were studied. Adult offspring were administered the Structured Clinical Interview for DSM-IV Axis I Disorders to establish the presence of psychopathology. Offspring aged 10-18 years were assessed using the School Aged Schedule for Affective Disorders and Schizophrenia, Present and Lifetime version, and parents of children under the age of ten completed the Child Behavioral Checklist. Data were examined using Cox proportional hazard regression.

RESULTS

There was no difference in hazard of mood disorders in the offspring of parents with BD as compared to the offspring of parents with MDD. However, a number of other parent and offspring characteristics increased the risk of mood, anxiety, externalizing, and substance use disorders in the offspring, including self-reported childhood abuse in the parent or offspring, offspring impulsive aggression, and the age at onset of parental mood disorder.

CONCLUSIONS

Mood disorders are highly familial, a finding that appears independent of whether the parent's condition is unipolar or bipolar, suggesting considerable overlap in the heritability of MDD and BD. Although parental characteristics had a limited influence on the risk of offspring psychopathology, reported childhood adversity, be it in the parent or child, is a harbinger of negative outcomes. These risk factors extend previous findings, and are consistent with diathesis-stress conceptualizations.

Impulsive responses to emotion as a transdiagnostic vulnerability to internalizing and externalizing symptoms

INTRODUCTION

This study explored the hypothesis that impulsive reactions to heightened emotion may reflect a transdiagnostic vulnerability to both externalizing and internalizing symptoms.

METHODS

A sample of undergraduates completed self-report measures of aggression, borderline personality disorder symptoms, anxiety symptoms, and alcohol problems, and a subset completed interviews that assessed suicidality. All participants also completed self-report measures relating to impulsivity. We predicted that emotion-reactive impulsivity, but not other aspects of impulsivity, would be related to the set of psychopathology symptoms.

RESULTS

Multiple regression analyses found that emotion-reactive impulsivity was uniquely related to each of the psychopathology scales, whereas non-emotion-relevant impulsivity was uniquely related only to alcohol problems.

CONCLUSION

Discussion focuses on limitations and clinical implications.

The Relationship between Impulsivity and Quality of Life in Euthymic Patients with Bipolar Disorder

OBJECTIVE

Bipolar disorder (BD) is characterized by elevated impulsivity, even during periods of remission. Many recovered BD patients have functional impairments, which can lead to poor quality of life (QoL). The aim of this study was to investigate the association between impulsivity and QoL in euthymic BD patients.

METHODS

A total of 56 remitted or recovered patients with type I or II BD, diagnosed based on Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria, were recruited. Psychiatrists administered the Clinical Global Impression (CGI) for BD and the Global Assessment of Functioning (GAF) scales and then interviewed the subjects to assess clinical variables. Patients completed the Barratt Impulsiveness Scale (BIS-11) and the World Health Organization Quality of Life Assessment Instrument-Brief Form (WHOQoL-BREF). Pearson correlations, univariate regression analyses, and multiple linear regression analyses were performed.

RESULTS

The BIS-11 total score was significantly correlated with the WHOQoL-BREF total score (r=-0.55, p<0.01) and with the WHOQoL-BREF subscales. After controlling for GAF score and other clinical variables, the BIS-11 total score (β=-0.43, p=0.001) was independently associated with overall QoL. Additionally, the BIS-11 total score was particularly strongly associated with the physical, psychological, and social domains of the multi-dimensional QoL scale.

CONCLUSION

Our results suggest that high impulsivity is related to low QoL in euthymic BD patients. Further studies are needed to examine whether interventions for high impulsivity effectively improve QoL in patients with BD.

What makes Internet addicts continue playing online even when faced by severe negative consequences? Possible explanations from an fMRI study

In this study, we designed a continuous wins-and-losses task to monitor the mental activities during decision-making and their effects on subsequent decisions in Internet addiction disorder (IAD) subjects. In behavioral performance, IAD subjects show longer response time, lower repeat rate and greater Stroop effect than healthy controls. In neuroimaging results, IAD subjects show increased brain activities in the inferior frontal cortex, insula, anterior cingulate cortex and decreased activation in the caudate and posterior cingulate cortex after continuous wins than healthy controls. In addition, IAD subjects show increased brain activities in the inferior frontal gyrus and decreased brain activation in the posterior cingulate cortex after continuous losses. Thus, we concluded that IAD subjects engage more cognitive activities to finish the decision-making task. As a result, they cannot sufficiently focus on the executive function during this process. They also do not pay adequate attention to considering previous selections and relevant outcomes during decision-making.

Is there an empirical link between impulsivity and suicidality in bipolar disorders? A review of the current literature and the potential psychological implications of the relationship

OBJECTIVES

Suicide is highly prevalent among individuals with bipolar disorder and understanding the factors that increase risk for suicide may help to develop targeted interventions to prevent attempts. Impulsivity is thought to be an influential factor associated with suicidality and is also discussed as a key construct of bipolar disorder. The aim of this paper was to systematically review the current evidence to examine the association between impulsivity and suicidality in bipolar disorder.

METHODS

PsycInfo, Medline, and Web of Knowledge databases were searched for articles published up until March 2012. Papers were included if they assessed an adult sample of individuals with bipolar disorders, focused on suicidality (ideation with intent to die, suicide attempts, or completion), and used a validated measure to determine impulsivity.

RESULT

Sixteen papers were identified. Contrary to widespread belief, we found (i) a very inconsistent picture of results including positive, negative, and insignificant associations between impulsivity and suicidality; and (ii) some studies do not take into account important aspects such as state-trait or measurement issues.

CONCLUSIONS

The link between suicidality and impulsivity is less straightforward than often assumed. Drawing clear conclusions about the association is hampered by factors such as inconsistencies in defining suicidality, measuring impulsivity, and differentiating between impulsivity as a personality trait and impulsivity as a state (e.g., a consequence of substance use or premeditation of the attempt). We suggest that the association is less direct and that psychological models (e.g., Joiner's theory of suicidality) can help foster a more in-depth understanding regarding the relationship.

Antisocial personality disorder and borderline symptoms are differentially related to impulsivity and course of illness in bipolar disorder

BACKGROUND

Interactions between characteristics of bipolar and Axis II cluster B disorders are clinically and diagnostically challenging. Characteristics associated with personality disorders may be dimensional aspects of bipolar disorder. We investigated relationships among antisocial personality disorder (ASPD) or borderline personality disorder symptoms, impulsivity, and course of illness in bipolar disorder.

METHODS

Subjects with bipolar disorder were recruited from the community. Diagnosis was by structured clinical interview for DSM-IV (SCID-I and -II), psychiatric symptom assessment by the change version of the schedule for affective disorders and schizophrenia (SADS-C), severity of Axis II symptoms by ASPD and borderline personality disorder SCID-II symptoms, and impulsivity by the Barratt impulsiveness scale (BIS-11).

RESULTS

ASPD and borderline symptoms were not related to clinical state or affective symptoms. Borderline symptoms correlated with BIS-11 impulsivity scores, and predicted history of suicide attempts independently of the relationship to impulsivity. ASPD symptoms were more strongly related to course of illness, including early onset, frequent episodes, and substance-related disorders. These effects persisted after allowance for gender and substance-use disorder history.

CONCLUSIONS

Personality disorder symptoms appear to be dimensional, trait-like characteristics of bipolar disorder. ASPD and Borderline symptoms are differentially related to impulsivity and course of illness.

Is impulsivity a common trait in bipolar and unipolar disorders?

OBJECTIVES

  Impulsivity is increased in bipolar and unipolar disorders during episodes and is associated with substance abuse disorders and suicide risk. Impulsivity between episodes predisposes to relapses and poor therapeutic compliance. However, there is little information about impulsivity during euthymia in mood disorders. We sought to investigate trait impulsivity in euthymic bipolar and unipolar disorder patients, comparing them to healthy individuals and unaffected relatives of bipolar disorder patients.

METHODS

  Impulsivity was evaluated by the Barratt Impulsiveness Scale (BIS-11A) in 54 bipolar disorder patients, 25 unipolar disorder patients, 136 healthy volunteers, and 14 unaffected relatives. The BIS-11A mean scores for all four groups were compared through the Games-Howell test for all possible pairwise combinations. Additionally, we compared impulsivity in bipolar and unipolar disorder patients with and without a history of suicide attempt and substance abuse disorder.

RESULTS

  Bipolar and unipolar disorder patients scored significantly higher than the healthy controls and unaffected relatives on all measures of the BIS-11A except for attentional impulsivity. On the attentional impulsivity measures there were no differences among the unaffected relatives and the bipolar and unipolar disorder groups, but all three of these groups scored higher than the healthy participant group. There was no difference in impulsivity between bipolar and unipolar disorder subjects with and without suicide attempt. However, impulsivity was higher among bipolar and unipolar disorder subjects with past substance use disorder compared to patients without such a history.

CONCLUSIONS

  Questionnaire-measured impulsivity appears to be relatively independent of mood state in bipolar and unipolar disorder patients; it remains elevated in euthymia and is higher in individuals with past substance abuse. Elevated attentional and lower non-planning impulsivity in unaffected relatives of bipolar disorder patients distinguished them from healthy participants, suggesting that increased attentional impulsivity may predispose to development of affective disorders, while reduced attentional impulsivity may be protective.

Differential effects of dopamine transporter inhibitors in the rodent Iowa gambling task: relevance to mania

RATIONALE

The Iowa Gambling Task (IGT) can be used to quantify impulsive and risky choice behaviors in psychiatric patients, e.g., bipolar disorder (BD) sufferers. Although developing treatments for these behaviors is important, few predictive animal models exist. Inhibition of the dopamine transporter (DAT) can model profiles of altered motor activity and exploration seen in patients with BD. The effect of DAT inhibition on impulsive choices related to BD has received limited study however. We used a rodent IGT to elucidate the effects of similarly acting drugs on risky choice behavior.

OBJECTIVES

We hypothesized that (1) C57BL/6 mice could adopt the "safe" choice options in the IGT and (2) DAT inhibition would alter risk preference.

METHODS

Mice were trained in the IGT to a stable risk-preference and then administered the norepinephrine/DAT inhibitor amphetamine, or the more selective DAT inhibitors modafinil or GBR12909.

RESULTS

Mice developed a preference for the "safe" option, which was potentiated by amphetamine administration. GBR12909 or modafinil administration increased motor impulsivity, motivation significantly, and risk preference subtly.

CONCLUSIONS

The rodent IGT can measure different impulse-related behaviors and differentiate similarly acting BD-related drugs. The contrasting effects of amphetamine and modafinil in mice are similar to effects in rats and humans in corresponding IGT tasks, supporting the translational validity of the task. GBR12909 and modafinil elicited similar behaviors in the IGT, likely through a shared mechanism. Future studies using a within-session IGT are warranted to confirm the suitability of DAT inhibitors to model risk-preference in BD.

Clinical features associated with trait-impulsiveness in euthymic bipolar disorder patients

BACKGROUND

A strong association has been reported between trait-impulsiveness and bipolar disorder (BD). Much attention has been focused on this association, but subgroup analysis has generated conflicting results, raising questions about the role of trait-impulsiveness in suicidal behavior and substance misuse in bipolar patients.

METHOD

We compared Barratt Impulsiveness Scale-10 scores between 385 euthymic bipolar patients and 185 healthy controls. We then investigated possible association between impulsiveness scores and the following clinical characteristics: suicide attempt (SA), lifetime alcohol/cannabis misuse, rapid cycling and mixed episodes.

RESULTS

Bipolar patients and healthy controls had significantly different BIS-10 total score and subscores (motor, attentional and nonplanning impulsiveness) (all p values <0.0001). No association was observed between BIS-10 total score, personal history of SA, number of SA, age at first SA and history of violent SA. Higher BIS-10 total scores were associated with alcohol misuse (p=0.005), cannabis misuse (p<0.0001), with an additive effect for these two substances (p=0.005). Higher BIS-10 total scores were also associated with rapid cycling (p=0.006) and history of mixed episodes (p=0.002), with an additive effect of these two variables (p=0.0006).

LIMITATIONS

We used only one clinical measurement of impulsiveness and did not carry out cognitive assessment.

CONCLUSION

This study demonstrates that trait-impulsiveness may be considered as a dimensional feature associated with BD and with a more severe clinical expression of the disease, characterized by a history of substance misuse, rapid cycling and mixed episodes. We found no association between impulsiveness and SA characteristics in bipolar patients, confirming some previous negative results.

Abnormal temporal lobe white matter as a biomarker for genetic risk of bipolar disorder

BACKGROUND

Brain white matter (WM) abnormalities have been hypothesized to play an important role in the neurobiology of bipolar disorder (BD). The nature of these abnormalities is not well-characterized, however, and it is unknown whether they occur after disease onset or represent potential markers of genetic risk.

METHODS

We examined WM integrity (assessed via fractional anisotropy [FA]) with diffusion tensor imaging in patients with BD (n=26), unaffected siblings of patients with BD (n=15), and healthy volunteers (n=27) to identify WM biomarkers of genetic risk.

RESULTS

The FA differed significantly (p<.05; corrected) among the three groups within the right temporal WM. Unaffected siblings had FA values that were intermediate to and significantly different from those of healthy volunteers and patients with BD (healthy control subjects>unaffected siblings>BD). Moreover, FA values in this region correlated negatively and significantly with trait impulsivity in unaffected siblings. Probabilistic tractography indicated that the regional abnormality lies along the inferior fronto-occipital fasciculus, a large intrahemispheric association pathway.

CONCLUSIONS

Our results suggest that lower WM integrity in the right temporal lobe might be a biomarker for genetic risk of BD. It is conceivable that the attenuated nature of these WM abnormalities present in unaffected siblings allows for some preservation of adaptive emotional regulation, whereas more pronounced alterations observed in patients is related to the marked emotional dysregulation characteristic of BD.

Trait impulsivity is increased in bipolar disorder patients with comorbid alcohol use disorders

BACKGROUND

Up to 60% of bipolar disorder (BD) patients develop alcohol use disorders (AUD) at some point in their lives. The causes of this highly prevalent comorbidity are unknown. High trait impulsivity characterizes both isolated BD and AUD and may be a link to explain the association between BD and AUD. In this study, our aims were to investigate whether BD patients with comorbid AUD would present higher trait impulsivity levels compared to BD patients without comorbid AUD, and whether trait impulsivity levels differ within subgroups of BD according to the subcategory of AUD (abuse vs. dependence, alcoholism alone vs. alcoholism plus drug use disorders).

SAMPLING AND METHODS

Forty-seven outpatients with BD with comorbid AUD (alcoholic BD group) were compared to 66 outpatients with BD alone (nonalcoholic BD group) and to 90 healthy controls (HC). BD and AUD diagnoses were obtained using the Structured Clinical Interview for DSM-IV diagnoses. Impulsivity was assessed using the Barratt Impulsiveness Scale (BIS-11), a self-report instrument that measures trait impulsivity in three domains: nonplanning, attentional and motor.

RESULTS

Alcoholic BD patients scored significantly higher than nonalcoholic BD and HC on the total and on each subscale BIS scores. Within the alcoholic BD patients, alcohol abusers and alcohol dependents did not statistically differ from each other on the BIS-11 scores. BD patients with AUD plus drug use disorders presented statistically higher nonplanning impulsivity than BD patients with AUD alone.

CONCLUSIONS

This was a cross-sectional study and causal inferences about the relationship between impulsivity and the comorbidity phenomenon cannot be made. Increased impulsivity may be a trait marker for the co-occurrence between BD and AUD, and mediate some severe manifestations of this comorbidity.

Decision making in the Balloon Analogue Risk Task (BART): anterior cingulate cortex signals loss aversion but not the infrequency of risky choices

The inferior frontal gyrus/anterior insula (IFG/AI) and anterior cingulate cortex (ACC) are key regions involved in risk appraisal during decision making, but accounts of how these regions contribute to decision making under risk remain contested. To help clarify the roles of these and other related regions, we used a modified version of the Balloon Analogue Risk Task (Lejuez et al., Journal of Experimental Psychology: Applied, 8, 75-84, 2002) to distinguish between decision-making and feedback-related processes when participants decided to pursue a gain as the probability of loss increased parametrically. Specifically, we set out to test whether the ACC and IFG/AI regions correspond to loss aversion at the time of decision making in a way that is not confounded with either reward-seeking or infrequency effects. When participants chose to discontinue inflating the balloon (win option), we observed greater ACC and mainly bilateral IFG/AI activity at the time of decision as the probability of explosion increased, consistent with increased loss aversion but inconsistent with an infrequency effect. In contrast, we found robust vmPFC activity when participants chose to continue inflating the balloon (risky option), consistent with reward seeking. However, in the cingulate and in mainly bilateral IFG regions, blood-oxygenation-level-dependent activation decreased when participants chose to inflate the balloon as the probability of explosion increased, findings that are consistent with a reduced loss aversion signal. Our results highlight the existence of distinct reward-seeking and loss-averse signals during decision making, as well as the importance of distinguishing between decision and feedback signals.

Trait impulsivity in suicide attempters: preliminary study

Suicide attempt is a risk factor for suicide. To investigate trait impulsivity among suicide attempters, 93 attempters admitted to an emergency department and 113 healthy controls were evaluated using the Japanese version of the Barratt Impulsiveness Scale (BIS-11J). Impulsivity was analyzed in relation to clinical data in the attempters. Total BIS-11J, attention impulsiveness, and motor impulsiveness scores were significantly higher in the attempters than in the controls. Both total BIS-11J and non-planning impulsiveness scores were significantly higher in attempters with schizophrenia and other psychotic disorders among the diagnostic groups. Control of impulsivity should be considered as one of the targets for suicide prevention.

Volumetric reductions in the subgenual anterior cingulate cortex in adolescents with bipolar I disorder

OBJECTIVES

A range of prefrontal and subcortical volumetric abnormalities have been found in adults and adolescents with bipolar disorder. It is unclear, however, if these deficits are present early in the onset of mania or are a consequence of multiple mood episodes or prolonged exposure to medication. The goal of this study was to examine whether youth with bipolar I disorder who recently experienced their first episode of mania are characterized by brain volumetric abnormalities.

METHODS

Anatomical images from magnetic resonance imaging of 26 13- to 18-year-old adolescents with bipolar I disorder and 24 age-comparable healthy controls with no personal or family history of psychopathology were analyzed using whole-brain voxel-based morphometry (VBM).

RESULTS

Compared with healthy controls, adolescents with bipolar I disorder had significantly less gray matter volume in the left subgenual cingulate cortex [p<0.05, family-wise error (FWE)-corrected].

CONCLUSIONS

Adolescents with a recent single episode of mania have smaller subgenual cingulate cortex volume than do their healthy counterparts, suggesting that this anomaly occurs early in the onset of, or may predate the disorder. Longitudinal studies are needed to examine the impact of this volumetric reduction on the course and outcome of this disorder.

Rash impulsiveness and reward sensitivity in relation to risky drinking by university students: potential roles of frontal systems

BACKGROUND

Two forms of impulsivity, rash impulsiveness and reward sensitivity, have been proposed to reflect aspects of frontal lobe functioning and promote substance use. The present study examined these two forms of impulsivity as well as frontal lobe symptoms in relation to risky drinking by university students.

METHODS

University undergraduates aged 18-26years completed the Alcohol Use Disorders Identification Test (AUDIT), Barratt Impulsiveness Scale (BIS-11), Sensitivity to Punishment and Sensitivity to Reward Questionnaire (SPSRQ), Frontal Systems Behavior Scale (FrSBe), and a demographics questionnaire assessing age, gender, and age of onset of weekly drinking (AOD).

RESULTS

AUDIT-defined harmful drinkers reported earlier AOD and scored higher on BIS-11, the Sensitivity to Reward (SR) scale of the SPSRQ, and the Disinhibition and Executive Dysfunction scales of the FrSBe compared to lower risk groups. Differences remained significant after controlling for duration of alcohol exposure. Path analyses indicated that the influence of SR on AUDIT was mediated by FrSBe Disinhibition, whereas the influence of BIS-11 on AUDIT was mediated by both Disinhibition and Executive Dysfunction scales of the FrSBe.

CONCLUSIONS

Findings tentatively suggest that the influence of rash impulsiveness on drinking may reflect dysfunction in dorsolateral prefrontal and orbitofrontal systems, whereas the influence of reward sensitivity on drinking may primarily reflect orbitofrontal dysfunction. Irrespective of the underlying functional brain systems involved, results appear to be more consistent with a pre-drinking trait interpretation than effects of alcohol exposure.

Impulsivity in the general population: a national study

OBJECTIVE

The construct of impulsivity is an important determinant of personality differences, psychiatric disorders, and associated risk-taking behaviors. Most existing knowledge about impulsivity comes from clinical samples. To date, no study has estimated the prevalence of impulsivity and examined its correlates in the general population.

METHOD

We analyzed data from a large national sample of the United States population. Face-to-face surveys of 34 653 adults aged 18 years and older residing in households were conducted during the 2004-2005 period. Diagnoses of mood, anxiety, and drug disorders as well as personality disorders were based on the Alcohol Use Disorder and Associated Disabilities Interview Schedule-DSM-IV Version.

RESULTS

Impulsivity was common (17% of the sample), particularly among males and younger individuals, and associated with a broad range of axis I and II disorders, particularly drug dependence, cluster B, dependent and schizotypal personality disorders, bipolar disorder and ADHD. It was associated with behavioral disinhibition, attention deficits, and lack of planning. Individuals with impulsivity were more likely to engage in behaviors that could be dangerous to themselves or others, including driving recklessly, starting fights, shoplifting, perpetrating domestic violence and trying to hurt or kill themselves. They were exposed to higher risk of lifetime trauma and to substantial physical and psychosocial impairment.

CONCLUSION

Given the association of impulsivity with psychiatric disorders and multiple adverse events, there is a need to target impulsivity in prevention and treatment efforts.

Trait impulsivity as an endophenotype for bipolar I disorder

OBJECTIVE

Impulsivity, conceptualized as impairment in planning and poor attentional and inhibitory control, is a key feature of bipolar disorder. Familial risk for bipolar disorder is known to affect inhibitory control but its impact on the attentional and planning dimensions of impulsivity is still unclear.

METHODS

We administered the Barratt Impulsiveness Scale, version 11 (BIS-11) to 54 euthymic individuals with DSM-IV bipolar I disorder, 57 of their clinically unaffected siblings, and 49 healthy comparison subjects. Groups were compared on the attentional (rapid shifts in attention/impatience with complexity), motor (acting impetuously), and non-planning (absence of weighing upon long-term consequences of actions) subscales of the BIS-11, and on total BIS-11 score. To investigate functional implications of trait impulsivity, total BIS-11 score was examined in relation to current psychosocial functioning and criminal history.

RESULTS

Individuals with bipolar I disorder had elevated scores compared to healthy comparison subjects on BIS-11 total score and all three subscales (p < 0.0001). Unaffected siblings had elevated BIS-11 total score (p = 0.0037), motor (p = 0.0027), and non-planning (p = 0.0379) subscales in comparison to unrelated healthy controls. Total BIS-11 score was negatively associated with global assessment of functioning (GAF) score (β = -0.32, p < 0.0001).

CONCLUSIONS

 Our results suggest that impulsivity is sensitive to familial liability for the illness, making it a potential endophenotype for bipolar disorder.

Emotional dysfunction as a marker of bipolar disorders

BACKGROUND

Assessment of emotional reactivity, defined as rapid emotional responses to salient environmental events, has been neglected in mood disorders. This article reviews data showing the relevance of using emotional reactivity to better characterize bipolar mood episodes.

METHOD

We reviewed clinical data on emotional reactivity during all phases of bipolar disorders (euthymic, manic, mixed and depressive states) and brain-imaging, neurochemical, genetic studies related to emotional reactivity disturbances.

RESULT

Euthymic bipolar patients show mild abnormalities (hypersensitivity to emotional stimuli and higher arousability) in comparison to controls. Both manic and mixed states are characterized by a significant increase in emotional reactivity. Furthermore, emotional reactivity may discriminate between two types of bipolar depression, the first being characterized by emotional hypo-reactivity and global behavioral inhibition, the second by emotional hyper-reactivity. Brain-imaging studies can help to identify the underlying mechanisms involved in disturbances of emotional reactivity.

CONCLUSION

Emotional reactivity can be used to refine more homogeneous pathophysiological subtypes of mood episodes. Future research should explore possible correlations between biomarkers, response to treatments and these clinical phenotypes.

Does anxiety increase impulsivity in patients with bipolar disorder or major depressive disorder?

The objective of this study was to examine whether anxiety increases impulsivity among patients with bipolar disorder (BPD) and major depressive disorder (MDD). Subjects comprised 205 BPD (mean age ± SD 36.6 ± 11.5 y; 29.3% males) and 105 with MDD (mean age ± SD 38 ± 13.1 y; 29.5% males) diagnosed using the DSM-IV-SCID. Impulsivity was assessed with the Barratt Impulsivity Scale and anxiety with the Hamilton Anxiety Rating Scale. Comorbid anxiety disorders were present in 58.9% of the BPD and 29.1% of MDD. BPD were significantly more impulsive than MDD (p < 0.001), and both BPD and MDD subjects showed significantly higher impulsivity when anxiety was present either as a comorbidity (p = 0.010) or as a symptom (p = 0.011). Impulsivity rose more rapidly with increasing anxiety symptoms in MDD than in BPD. The presence of anxiety, either as a comorbid disorder or as current anxiety symptoms, is associated with higher impulsivity in subjects with either BPD or MDD.

I want it now! Neural correlates of hypersensitivity to immediate reward in hypomania

BACKGROUND

Hypomania is associated with impulsive decision making and risk taking, characteristics that may arise from hypersensitivity to reward. To date, the neural dynamics underlying intertemporal reward processing have neither been characterized clinically nor in the general population. Taking vulnerability to hypomania as a surrogate model of impulsivity, we utilized event-related potentials to study the neural mechanisms of delay discounting.

METHODS

In the first experiment, 32 participants completed an established Two Choice Impulsivity Paradigm in which free choice between immediate and delayed rewards was used to quantify impulsivity behaviorally. In the second experiment, electroencephalography was recorded while 32 separately recruited participants completed a speeded response task involving gains and losses of monetary incentives to be paid at three different delays after the experiment.

RESULTS

In the first experiment, the hypomania-prone group made significantly more immediate choices than the control group. In the second experiment, the hypomania-prone group evidenced greater differentiation between delayed and immediate outcomes in early attention-sensitive (N1) and later reward-sensitive (feedback-related negativity) components. Proneness to hypomania was also associated with greater N1 amplitude to rewards per se.

CONCLUSIONS

These results indicate steeper delay discounting in hypomania at multiple stages of information processing. The N1 modulation by valence and delay suggests an attentional bias to immediate rewards, which may drive subsequent cognitive appraisal of outcomes (feedback-related negativity). These results highlight the early influence of attention on reward processing and provide support for reward dysregulation accounts of bipolar disorder. Potential implications for mindfulness training and other therapeutic interventions are highlighted.

Impulsivity and functional impairment in bipolar disorder

BACKGROUND

Impulsivity is substantially higher in bipolar patients (BP) and may be associated with a more severe course of illness, but no studies have so far examined the relationship between impulsivity and functional outcome in BP. Our goal was to investigate the functional impact of trait-impulsivity in BP.

METHODS

138 euthymic BP were recruited. All patients were assessed using an interview based on the Structured Clinical Interview for DSM Disorders (SCID). The Functioning Assessment Short Test (FAST) and the Barratt Impulsiveness Scale (BIS-11) were used to assess functional outcome and impulsivity, respectively. Seven multiple linear regressions, with each individual FAST subscale scores and overall FAST score as dependant variables, were conducted in order to evaluate the predictive role of trait-impulsivity on functional outcome.

RESULTS

After a multiple linear regression model, with the FAST total score as dependent variable, we found that depressive symptoms (β=1.580; p<0.001), number of hospitalizations (β=0.837; p=0.019) and impulsivity (β=0.319; p=0.004) were independently associated with overall functional impairment (F=6.854, df=9, p<0.001, adjusted R2=0.311).

LIMITATIONS

The cross-sectional design of the study.

CONCLUSIONS

Our results indicate that impulsivity, as well as depressive symptoms and the number of hospitalizations, is associated with overall functional impairment in BP. The assessment and treatment of impulsivity may be useful in improving functional outcome in BP.

Relationship between suicidality and impulsivity in bipolar I disorder: a diffusion tensor imaging study

BACKGROUND

Impulsivity is characteristic of individuals with bipolar disorder and may be a contributing factor to the high rate of suicide in patients with this disorder. Although white matter abnormalities have been implicated in the pathophysiology of bipolar disorder, their relationship to impulsivity and suicidality in this disorder has not been well-investigated.

METHODS

Diffusion tensor imaging scans were acquired in 14 bipolar disorder patients with a prior suicide attempt, 15 bipolar disorder patients with no prior suicide attempt, and 15 healthy volunteers. Bipolar disorder patients received clinical assessments including measures of impulsivity, depression, mania, and anxiety. Images were processed using the Tract-Based Spatial Statistics method in the FSL software package.

RESULTS

Bipolar disorder patients with a prior suicide attempt had lower fractional anisotropy (FA) within the left orbital frontal white matter (p < 0.05, corrected) and higher overall impulsivity compared to patients without a previous suicide attempt. Among patients with a prior suicide attempt, FA in the orbital frontal white matter region correlated inversely with motor impulsivity.

CONCLUSIONS

Abnormal orbital frontal white matter may play a role in impulsive and suicidal behavior among patients with bipolar disorder.

Early Maladaptive Schemas among patients diagnosed with bipolar disorder

BACKGROUND

Bipolar disorder is associated with a variety of cognitive features that seem to play a role in affective symptoms. Schema theory may serve as a unifying theory that would explain many of these features. This study is an exploratory investigation of schema theory's Early Maladaptive Schemas (EMSs) among individuals diagnosed with bipolar disorder.

METHODS

A sample of 74 participants with bipolar disorder and 99 mixed clinical controls (46 with unipolar depression and 53 with anxiety disorders) completed the Young Schema Questionnaire and comparison measures. Associations were investigated using univariate and multivariate analyses. Mean scores were compared with previously established benchmarks.

RESULTS

Participants with bipolar disorder demonstrate elevated scores on most EMSs, many at an intermediate position between nonclinical and mixed clinical control groups. When controlling for depression, participants with bipolar disorder exceed those with unipolar depression on Approval-Seeking/Recognition-Seeking and Entitlement/Grandiosity. Bipolar group membership is predicted by high scores on Approval-Seeking/Recognition-Seeking and low scores on Emotional Inhibition and Abandonment.

LIMITATIONS

Women were overrepresented. Axis II traits were not assessed, nor were manic symptoms in the mixed clinical sample.

CONCLUSIONS

Bipolar disorder is associated with a general activation of the EMSs. Approval-Seeking/Recognition-Seeking and Entitlement/Grandiosity seem to be particularly high, while Emotional Inhibition and Abandonment seem to be typically low. These EMS are highly consistent with characteristics of the bipolar spectrum. By demonstrating the activation of the EMSs, this study suggests that the EMS component of schema theory may be applied to bipolar disorder. Future research should explore how EMSs might interact with life events to trigger affective symptoms and, ultimately, the applicability of schema therapy to bipolar disorder.

Relationship of trait impulsivity with clinical presentation in euthymic bipolar disorder patients

The purpose of this study was to examine trait impulsivity in patients with bipolar disorder and explore the possible connections between impulsivity and clinical presentation of the illness. Diagnoses were based on the Structured Clinical Interview for DSM-IV. The sociodemographic and clinical properties of 71 patients with bipolar disorder, who were euthymic according to Young Mania Rating Scale and Hamilton Depression Scale scores, were recorded. Their trait impulsivity was evaluated by using the Barratt Impulsiveness Scale (BIS) and impulsivity subscale of the Temperament and Character Inventory, and the results were compared with 50 age- and sex-matched healthy controls and among patients with different clinical properties. All BIS-11 subscale scores were higher in bipolar than in comparison subjects. There were no effects of education and age. Elevated BIS-11 scores were associated with predominant depressive polarity, longer duration of illness and a history of psychotic mood episodes and suicide attempts. These relationships persisted when age, gender, and education were taken into account. These results show that after accounting for common confounding factors, trait-like impulsivity was substantially higher in subjects with bipolar disorder than in nonbipolar comparison subjects and may vary according to different clinical presentations.

Antisocial personality and bipolar disorder: interactions in impulsivity and course of illness

Antisocial personality disorder (ASPD) and bipolar disorder are both characterized by impulsive behavior, increased incarceration or arrest, addictive disorders and suicidal behavior. These characteristics appear more severe in the combined disorders. Individuals with ASPD who also have bipolar disorder have higher rates of addictive disorders and suicidal behavior and are more impulsive, as measured by questionnaires or behavioral laboratory tests. Those with bipolar disorder who have ASPD have higher rates of addictive, criminal and suicidal behavior, earlier onset of bipolar disorder with a more recurrent and predominately manic course and increased laboratory-measured, but not questionnaire-rated, impulsivity. These characteristics may result in part from differential impulsivity mechanisms in the two disorders, with bipolar disorder driven more by excessive catecholamine sensitivity and ASPD by deficient serotonergic function.

The relationship of manic episodes and drug abuse to sexual risk behavior in patients with co-occurring bipolar and substance use disorders: a 15-month prospective analysis

Risky sexual behavior is common among individuals with bipolar and substance use disorders. This 15-month prospective study examined the effects of between-subject differences and within-subject changes in mood symptoms and drug use on sexual risk behavior among 61 patients with both disorders. Participants completed five post-treatment follow-up assessments at 3-month intervals. Using a multivariate mixed-effects model analysis, more average weeks of mania (between-subject difference) was associated with greater sexual risk, but change in weeks of mania (within-subject change) was not; depression was unrelated to sexual risk. In addition, within-subject increases in days of cocaine use predicted increases in sexual risk. Results underscore the importance of substance abuse treatment and suggest that bipolar patients with active and/or recurrent mania are in need of targeted HIV prevention services. Further research is needed to test whether individual differences in impulsivity may explain the association between mania and sexual risk.

Impulsivity, aggression and suicidal behavior in unipolar and bipolar disorders

BACKGROUND

Predictors of suicidal behaviors (SB) in bipolar (BD) and major depressive disorder (MDD) patients are poorly understood. It has been recognized that behavioral dysregulation characterizes SB with traits of impulsivity and aggression being particularly salient. However, little is known about how these traits are segregated among mood disorder patients with and without a history of suicide attempt (SA).

METHODS

This article aims to compare impulsivity and aggression between 143 controls, 138 BD and 186 MDD subjects with or without a history of SA.

RESULTS

BD and MDD patients showed higher impulsivity scores (BIS-10 = 57.9 vs. 44.7, p < 0.0001) and more severe lifetime aggression than controls (Lifetime History of Aggression = 7.3 vs. 3.9, p < 0.0001). Whereas impulsivity helped to distinguish MDD subjects without a history of SA from those with such a history, this was not the case in BD subjects where no difference in impulsive traits was observed between BD without and with history of SA (57.2 vs. 63.2 for BIS-10; p = 0.259). Impulsive and aggressive traits were strongly correlated in suicide attempters (independently of the diagnosis) but not in non-suicide attempters.

LIMITATIONS

Dimensional traits were not characterized at different stages of illness.

CONCLUSIONS

Impulsivity, as a single trait, may be a reliable suicide risk marker in MDD but not in BD patients, and its strong correlation with aggressive traits seems specifically related to SB. Our study therefore suggests that the specific dimension of impulsive aggression should be systematically assessed in mood disorder patients to address properly their suicidal risk.