title: Drinking motives in female smokers: factor structure, alcohol dependence, and genetic influences.
abstract: BACKGROUND
  Alcohol and tobacco use often co-occur. Human and animal studies indicate that nicotine increases alcohol's rewarding effects and the motivation to consume it. The aims of this study were to examine whether the factorial architecture of self-reported motivations to consume alcohol differed between regular and nonregular cigarette smokers while taking into account the lifetime history of alcohol dependence and psychopathology, and to estimate the genetic and environmental influences on the motivations.
  
  
  METHODS
  Using data on 2,189 monozygotic and dizygotic female twins, we examined the factorial structure (item thresholds and factor loadings, means, and variances) of the items from the Drinking Motives Questionnaire (DMQ) in regular and nonregular smokers. Post hoc tests examined the association between the latent drinking motives factors and alcohol dependence in both groups. Twin models were fitted to the latent drinking motives factors, testing for variations in the magnitude of additive genetic, shared, and nonshared environmental influences between the groups.
  
  
  RESULTS
  The 4 DMQ factors (social, conformity, coping, and enhancement) were recovered in both groups, and their measurement structure was consistent across the groups. Regular smokers reported higher levels of coping, enhancement, and social motives while nonregular smokers reported higher conformity motives. Alcohol dependence was associated with higher scores on all motives in both groups; however, in a regression analysis that included all of the motives as predictor variables, only coping was significantly related to alcohol dependence. While twin models revealed evidence for substantially greater genetic influences on enhancement (h² = 0.40), coping (h² = 0.35) and social (h² = 0.37) drinking motives in regular compared to nonregular smokers, the power to statistically distinguish the 2 groups was low.
  
  
  CONCLUSIONS
  While the measurement structure of the drinking motive factors appears to be similar across regular and nonregular smokers, regular smokers report more motivation to drink for internal affect-related reasons and to obtain social reward. Of all the motives, coping was the most robust predictor of alcohol dependence in both the regular and the nonregular smokers. Further, genetic influences might play a larger role in drinking motives among regular smokers, which provides tentative evidence for latent genetic × smoking status interactions.
authors.affiliation: Department of Psychiatry, Washington University School of Medicine, St Louis, Missouri 63110, USA. kristjas@psychiatry.wustl.edu
authors.forename: Sean D
authors.initials: SD
authors.lastname: Kristjansson
authors.forename: Arpana
authors.initials: A
authors.lastname: Agrawal
authors.forename: Andrew K
authors.initials: AK
authors.lastname: Littlefield
authors.forename: Michele L
authors.initials: ML
authors.lastname: Pergadia
authors.forename: Christina N
authors.initials: CN
authors.lastname: Lessov-Schlaggar
authors.forename: Carolyn E
authors.initials: CE
authors.lastname: Sartor
authors.forename: Kathleen K
authors.initials: KK
authors.lastname: Bucholz
authors.forename: Pamela A F
authors.initials: PA
authors.lastname: Madden
authors.forename: M Lynne
authors.initials: ML
authors.lastname: Cooper
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Sher
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Heath
mesh_terms: D000328:Adult; D000428:Alcohol Drinking / Q000235:genetics* / Q000523:psychology*; D000437:Alcoholism / Q000235:genetics* / Q000523:psychology*; D015331:Cohort Studies; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D009042:Motivation; D011569:Psychiatric Status Rating Scales; D012907:Smoking / Q000235:genetics* / Q000523:psychology*; D012919:Social Behavior; D012925:Social Conformity; D011795:Surveys and Questionnaires; D014029:Tobacco Use Disorder / Q000523:psychology*; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic; D055815:Young Adult