title: Sex modulates approach systems and impulsivity in substance dependence.
abstract: BACKGROUND
  Personality traits such as pathological engagement in approach behaviors, high levels of impulsivity and heightened negative affect are consistently observed in substance dependent individuals (SDI). The clinical course of addiction has been shown to differ between sexes. For example, women increase their rates of consumption of some drugs of abuse more quickly than men. Despite the potential influence of personality and sex on features of addiction, few studies have investigated the interaction of these factors in substance dependence.
  
  
  METHODS
  Fifty-one SDI (26 males, 25 females) and 66 controls (41 males, 25 females) completed the Behavioral Inhibition/Behavioral Activation System (BIS/BAS) Scales, the Barratt Impulsiveness Scale, and the Positive and Negative Affect Schedule (PANAS-X). Data were analyzed with 2×2 ANCOVAs testing for main effects of group, sex and group by sex interactions, adjusting for education level.
  
  
  RESULTS
  Significant group by sex interactions were observed for BAS scores [F(1,116)=7.03, p<.01] and Barratt Motor Impulsiveness [F(1,116)=6.11, p<.02] with female SDI showing the highest approach tendencies and impulsivity followed by male SDI, male controls, and finally female controls. SDI scored higher on negative affect [F(1,116)=25.23, p<.001] than controls. Behavioral Inhibition System scores were higher in women than men [F(1,116)=14.03, p<.001].
  
  
  CONCLUSIONS
  Higher BAS and motor impulsivity in SDI women relative to SDI men and control women suggest that personality traits that have been previously associated with drug use may be modulated by sex. These factors may contribute to differences in the disease course observed in male compared to female drug users.
authors.affiliation: University of Colorado School of Medicine, Department of Radiology, 12700 E. 19th Avenue, Mailstop C278, Aurora, CO 80045, USA.
authors.forename: Robert I
authors.initials: RI
authors.lastname: Perry
authors.forename: Theodore
authors.initials: T
authors.lastname: Krmpotich
authors.forename: Laetitia L
authors.initials: LL
authors.lastname: Thompson
authors.forename: Susan K
authors.initials: SK
authors.lastname: Mikulich-Gilbertson
authors.forename: Marie T
authors.initials: MT
authors.lastname: Banich
authors.forename: Jody
authors.initials: J
authors.lastname: Tanabe
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D016022:Case-Control Studies; D017831:Diagnosis, Dual (Psychiatry) / Q000523:psychology; D005260:Female; D006801:Humans; D007175:Impulsive Behavior / Q000150:complications / Q000523:psychology*; D007266:Inhibition, Psychological; D008297:Male; D010555:Personality Inventory; D012727:Sex Characteristics; D019966:Substance-Related Disorders / Q000150:complications / Q000523:psychology*
keywords: Affect; Approach systems; Impulsivity; Sex; Substance dependence