title: Physical activity moderates the association between nicotine dependence and depression among U.S. smokers.
abstract: OBJECTIVE
  Research demonstrates that nicotine dependence and depression are associated and that physical activity is effective in reducing depression symptoms. However, our understanding of the potential beneficial effects of physical activity on depression in current smokers is more limited. The purpose of this study was to examine whether physical activity moderates the association between nicotine dependence and depression in U.S. smokers.
  
  
  METHODS
  Cross-sectional.
  
  
  METHODS
  National Health and Nutrition Examination Survey 2005-2006.
  
  
  METHODS
  Four hundred forty-one current adult smokers.
  
  
  METHODS
  Participants wore an accelerometer for at least 4 days and completed questionnaires to assess nicotine dependence and depression.
  
  
  METHODS
  Effect modification and statistical interaction models were used.
  
  
  RESULTS
  Both models were significant. With regard to the statistical interaction model, and after controlling for age, gender, race/ethnicity, education, comorbidity index, homocysteine, cotinine, total cholesterol, sedentary behavior, and vitamins C, D, and E, objectively measured physical activity moderated the association between nicotine dependence and depression (interaction variable: odds ratio = 3.43; 95% confidence interval: 1.02-11.51; p = .04).
  
  
  CONCLUSIONS
  In this national sample of current smokers, physical activity moderated the association between nicotine dependence and depression. These results suggest that those individuals with nicotine dependence and who are less physically active are more likely to be depressed than what would be expected on the basis of the individual effects of nicotine and physical inactivity separately.
authors.forename: Paul D
authors.initials: PD
authors.lastname: Loprinzi
authors.forename: Jerome F
authors.initials: JF
authors.lastname: Walker
authors.forename: Christy
authors.initials: C
authors.lastname: Kane
authors.forename: Bradley J
authors.initials: BJ
authors.lastname: Cardinal
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D003863:Depression / Q000453:epidemiology / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D009749:Nutrition Surveys; D014029:Tobacco Use Disorder / Q000453:epidemiology / Q000523:psychology*; D014481:United States / Q000453:epidemiology
keywords: Accelerometry; Epidemiology; Exercise; Health focus: smoking control/physical activity; Manuscript format: quantitative research; Mental Health; National Health and Nutrition Examination Survey (NHANES); Outcome measure: cognitive; Prevention Research; Research purpose: modeling/relationship testing, descriptive; Setting: national; Strategy: education, behavior change; Study design: cross-sectional; Target population age: adults; Target population circumstances: education, race/ethnicity; Tobacco