title: Trait impulsivity and increased pre-attentional sensitivity to intense stimuli in bipolar disorder and controls.
abstract: 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.
authors.affiliation: Menninger Department of Psychiatry and Behavioral Sciences, Baylor College of Medicine, One Baylor Plaza, BCM350, Houston, TX 77030, USA.
authors.forename: Marijn
authors.initials: M
authors.lastname: Lijffijt
authors.affiliation: Department of Psychiatry and Behavioral Sciences, The University of Texas Health Sciences Center, Houston, TX 77054, USA.
authors.forename: Scott D
authors.initials: SD
authors.lastname: Lane
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Virginia Commonwealth University School of Medicine, Richmond, VA, USA.
authors.forename: F Gerard
authors.initials: FG
authors.lastname: Moeller
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Virginia Commonwealth University School of Medicine, Richmond, VA, USA.
authors.forename: Joel L
authors.initials: JL
authors.lastname: Steinberg
authors.affiliation: Mental Health Care Line, Michael E. DeBakey VA Medical Center, 2002 E. Holcombe Blvd, Houston, TX 77030, USA; Menninger Department of Psychiatry and Behavioral Sciences, Baylor College of Medicine, One Baylor Plaza, BCM350, Houston, TX 77030, USA. Electronic address: acswann@bcm.edu.
authors.forename: Alan C
authors.initials: AC
authors.lastname: Swann
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001288:Attention / Q000502:physiology*; D001714:Bipolar Disorder / Q000503:physiopathology* / Q000523:psychology*; D016022:Case-Control Studies; D004493:Education; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D007175:Impulsive Behavior / Q000502:physiology*; D008297:Male; D008568:Memory / Q000502:physiology; D008875:Middle Aged; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D011930:Reaction Time / Q000502:physiology; D012307:Risk Factors; D012737:Sex Factors; D055815:Young Adult
keywords: Bipolar disorder; Evoked potentials; Impulsive behavior; Loudness perception; Personality; Sensation seeking