Ernest S. Barratt

Factor structure of the barratt impulsiveness scale

The purpose of the present study was to revise the Barratt Impulsiveness Scale Version 10 (BIS-10), identify the factor structure of the items among normals, and compare their scores on the revised form (BIS-11) with psychiatric inpatients and prison inmates. The scale was administered to 412 college undergraduates, 248 psychiatric inpatients, and 73 male prison inmates. Exploratory principal components analysis of the items identified six primary factors and three second-order factors. The three second-order factors were labeled Attentional Impulsiveness, Motor Impulsiveness, and Nonplanning Impulsiveness. Two of the three second-order factors identified in the BIS-11 were consistent with those proposed by Barratt (1985), but no cognitive impulsiveness component was identified per se. The results of the present study suggest that the total score of the BIS-11 is an internally consistent measure of impulsiveness and has potential clinical utility for measuring impulsiveness among selected patient and inmate populations.

Factor Analysis of Some Psychometric Measures of Impulsiveness and Anxiety

Two orthogonal personality traits or predispositions, impulsiveness and anxiety, have been invariant in five separate factor analyses. One of these analyses is presented here along with an item analysis of the Barratt Impulsiveness Scale (BIS) which has a high loading on the impulsiveness factor. The BIS has never significantly correlated with any of the various anxiety or emotional stability measures in over 50 administrations of the scale, further evidence for the invariance of these two second-order factors.

The impact of impulsivity on cocaine use and retention in treatment.

To determine whether impulsivity was related to severity of drug use and treatment outcome, 50 cocaine dependent subjects underwent baseline measures of severity of current cocaine use and the Barratt Impulsiveness Scale (BIS-11). The hypothesis of the study was that there would be a significant correlation between impulsivity and cocaine use severity. As predicted, there was a significant correlation between BIS-11 total scores and self-reported average daily cocaine use as well as cocaine withdrawal symptoms. A subset of 35 patients underwent a 12-week double-blind placebo controlled trial of buspirone and group therapy. Subjects with high baseline impulsivity remained in the study a significantly shorter period than did subjects with lower baseline impulsivity. This study shows that impulsivity is a significant predictor of cocaine use and treatment retention, and suggests the need for targeting impulsivity in cocaine dependence treatment.

Neuropsychological and cognitive psychophysiological substrates of impulsive aggression

The purpose of this study was to test whether subjects who commit impulsive vs non-impulsive aggression differ on measurements of personality, neuropsychology, and cognitive psychophysiology, and whether these differences can yield information regarding the etiology of impulsive aggression. Subjects were two groups of prison inmates, distinguished by their committal of impulsive or nonimpulsive aggression, and matched noninmate controls. All inmates met DSM III-R criteria for an antisocial personality disorder but for no other disorder. Impulsiveness, anger, and peak P300 latencies did not differ between the inmate groups, but verbal symbol decoding and peak P300 amplitudes did. Impulsiveness and verbal skills were inversely correlated. Impulsiveness was inversely correlated with, and verbal skills positively correlated with P300 amplitudes. The results indicate that aggression is not homogenous, even among antisocial persons, and that impulsive aggression is related to neuropsychological and cognitive psychophysiological measures of information processing beyond those factors related to criminality alone.

Increased impulsivity in cocaine dependent subjects independent of antisocial personality disorder and aggression

Several previous studies show a relationship between impulsivity and substance abuse; however, it is unclear whether the increased impulsivity seen in substance dependent groups is specifically related to substance abuse, or if it is due to concomitant antisocial personality disorder (ASPD) or aggression. The issue of whether impulsivity is specifically related to substance abuse is important since it has a bearing on risk factors for development of substance abuse. To determine whether cocaine dependent subjects show increased impulsivity independent of ASPD, the Barratt impulsiveness scale (BIS-11), a delayed reward laboratory measure of impulsivity, and the life history of aggression scale were administered to 49 cocaine dependent subjects and 25 controls. Results showed that cocaine dependent subjects with ASPD were more impulsive and aggressive than controls, but cocaine dependent subjects without ASPD were also more impulsive compared to controls. Controlling for aggression history, cocaine dependent subjects without ASPD continued to have elevated impulsivity as measured by the BIS-11, but not the delayed reward task. This study supports the hypothesis that the increased impulsivity as measured by the BIS-11 in cocaine dependent individuals is not exclusively due to concomitant increases in aggression or ASPD.

Reduced Anterior Corpus Callosum White Matter Integrity is Related to Increased Impulsivity and Reduced Discriminability in Cocaine-Dependent Subjects: Diffusion Tensor Imaging

Brain imaging studies find evidence of prefrontal cortical dysfunction in cocaine-dependent subjects. Similarly, cocaine-dependent subjects have problems with behaviors related to executive function and impulsivity. Since prefrontal cortical axonal tracts cross between hemispheres in the corpus callosum, it is possible that white matter integrity in the corpus callosum could also be diminished in cocaine-dependent subjects. The purpose of this study was to compare corpus callosum white matter integrity as measured by the fractional anisotropy (FA) on diffusion tensor imaging (DTI) between 18 cocaine-dependent subjects and 18 healthy controls. The Barratt Impulsiveness Scale (BIS-11) and a continuous performance test: the Immediate and Delayed Memory Task (IMT/DMT) were also collected. Results of the DTI showed significantly reduced FA in the genu and rostral body of the anterior corpus callosum in cocaine-dependent subjects compared to controls. Cocaine-dependent subjects also had significantly higher BIS-11 scores, greater impulsive (commission) errors, and reduced ability to discriminate target from catch stimuli (discriminability) on the IMT/DMT. Within cocaine dependent subjects there was a significant negative correlation between FA in the anterior corpus callosum and behavioral laboratory measured impulsivity, and there was a positive correlation between FA and discriminability. The finding that reduced integrity of anterior corpus callosum white matter in cocaine users is related to impaired impulse control and reduced ability to discriminate between target and catch stimuli is consistent with prior theories regarding frontal cortical involvement in impaired inhibitory control in cocaine-dependent subjects.

The Effects of Phenytoin on Impulsive and Premeditated Aggression: A Controlled Study

Studies of the effects of phenytoin on aggression have produced equivocal results primarily because of a lack of (1) common objective criterion measures of aggressive acts across studies; (2) rigorous inclusion and exclusion criteria for selecting subjects; and (3) a nosologic basis for classifying different types of aggression. The current study was designed to remedy these deficiencies. Aggression was defined using a nosology that defines three types of aggression: (1) medically related; (2) premeditated; and (3) impulsive. The purpose of this study was to test the hypothesis that phenytoin will decrease impulsive aggressive acts but not have a significant influence on premeditated aggressive acts. Sixty inmates were divided into two groups on the basis of committing primarily impulsive aggressive acts or premeditated aggressive acts while in prison. Medical aggression was ruled-out by subject selection. The study used a double-blind, placebo-controlled, crossover design. As hypothesized, phenytoin (200 mg a.m. and 100 mg p.m.) significantly reduced impulsive aggressive acts but not premeditated aggressive acts. Event-related potentials (ERPs) measured information processing in the cortex during drug/placebo conditions. The amplitudes of P300 ERP waveforms among impulsive aggressive subjects were increased significantly during the phenytoin condition but not during the placebo condition. There were no significant changes in P300 ERP waveforms between drug/placebo conditions among nonimpulsive aggressive subjects.

The biological basis of impulsiveness: the significance of timing and rhythm disorders

Abstract High-impulsive subjects often do say things on the spur of the moment and/or make up their minds quickly. The description of impulsivity as a personality trait involves a number of basic research questions including: 1. 1. From a psychometric viewpoint, how inclusive or broad is impulsivity as a personality trait? 2. 2. How does impulsivity relate to other personality traits? 3. 3. Is there a pattern of biological correlates of impulsivity that is distinct from other personality traits? 4. 4. What is the relationship between cognitive and behavioral impulsivity? This paper addresses those four questions. Psychometric analysis of issues in impulsivity indicates the need for a distinction between broad and narrow impulsivity traits and further redefinition of the latter in terms of cognitive and motor components. This research has also shown that impulsiveness has an orthogonal relationship with measures of anxiety. In perceptual-motor tasks, high-impulsive subjects perform less efficiently and with greater variability on a wide range of these tasks, and in particular when the task involves responding to two or more sequential stimuli. High-impulsive subjects underproduce time intervals in time-judgment tasks; this and other findings suggest that high-impulsive subjects have a faster cognitive tempo than low-impulsive subjects. The interaction of impulsivity and anxiety in the performance of perceptual-motor tasks is also reflected in psychophysiological measures; differences in impulsivity are more evident with electrocortical measures and differences in anxiety are reflected in ANS measures while performing the tasks.

Reduced punishment sensitivity in neural systems of behavior monitoring in impulsive individuals.

This study measured the response-locked event-related potential during a flanker task with performance-based monetarily rewarding and punishing trials in 37 undergraduate students separated into high- and low-impulsive groups based on a median split on self-reported Barrett Impulsiveness Scale. The high-impulsive group had a smaller medial frontal error-related negativity (ERN) on punishment trials than the low-impulsive group. The medial prefrontal neural system of behavior monitoring, indexed by the ERN, appears less sensitive to punishment signals in normal impulsivity. This reduced punishment sensitivity in impulsivity, a personality variation associated with several mental and personality disorders including ADHD and substance abuse may be related to the tendency to select short-term rewards despite potential long-term negative consequences in these individuals.

Predicting borderline and antisocial personality disorder features in nonclinical subjects using measures of impulsivity and aggressiveness

This study examines impulsivity and aggressiveness dimensions as predictors of borderline (BPD) and antisocial (ASPD) personality disorder symptoms in nonclinical subjects. A total of 747 undergraduate university students were administered the Personality Diagnostic Questionnaire-4+, the Barratt Impulsiveness Scale-11, and the Buss-Durkee Hostility Inventory. Hierarchical regression analysis showed that motor impulsiveness, irritability, resentment, and guilt predicted BPD symptoms among university students after controlling for the effect of ASPD and depressive symptoms. ASPD symptoms were predicted by motor impulsiveness, physical aggression, indirect aggression, and negativism. These results indicate that in nonclinical subjects BPD and ASPD symptoms share a common impulsivity dimension but are linked to different aggressiveness facets.