title: Adolescent alcohol and tobacco use: onset, persistence and trajectories of use across two samples.
abstract: OBJECTIVE
  We examined the alcohol-tobacco relationship using two prospective, ethnically diverse samples. Trajectories of alcohol and tobacco use are portrayed overall and by sex and ethnicity. Using prospective analyses, we examine directional influences between alcohol and tobacco use, and we characterize initiation versus persistence of drinking and smoking as a function of use of the other substance.
  
  
  METHODS
  Data were from the National Longitudinal Study of Adolescent Health (AddHealth) and the Adolescent Health Risk Study (AHRS). Follow-up intervals for AddHealth and AHRS were 1 and 5 years, respectively.
  
  
  METHODS
  AddHealth respondents (n = 4831) were on average 14.8 years old (48% male, 23% black, 61% white) and AHRS respondents (n = 1814) were on average 16.7 years old (47% male, 44% black, 49% white).
  
  
  METHODS
  Two alcohol consumption variables and two smoking variables were used: drinking frequency and heavy drinking frequency, and regular (current) smoking and daily number of cigarettes.
  
  
  RESULTS
  Alcohol and tobacco use exhibited monotonic increases over adolescence and young adulthood. Men and white respondents reported more use than women and black respondents. Alcohol and tobacco were moderately associated at both times. Analyses revealed that prior alcohol use predicted tobacco use more strongly than the converse. Initiation of smoking was a function of prior drinking; to a lesser extent, initiation of drinking was a function of prior smoking. Persistence of smoking was a function of prior drinking and persistence of drinking was a function of prior smoking.
  
  
  CONCLUSIONS
  Provisional support exists for the claim that alcohol use predicts tobacco use more strongly than the converse. For both drinking and smoking, onset and persistence are predicted by prior use of the other substance, and these associations were robust across sex and ethnicity.
authors.affiliation: Psychology Department, University of Missouri-Columbia, 65211-0001, USA. JacksonKM@missouri.edu
authors.forename: Kristina M
authors.initials: KM
authors.lastname: Jackson
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Sher
authors.forename: M Lynne
authors.initials: ML
authors.lastname: Cooper
authors.forename: Phillip K
authors.initials: PK
authors.lastname: Wood
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior; D000375:Aging / Q000523:psychology; D000428:Alcohol Drinking / Q000453:epidemiology*; D015897:Comorbidity; D005260:Female; D006801:Humans; D008297:Male; D011446:Prospective Studies; D012907:Smoking / Q000453:epidemiology*; D014481:United States / Q000453:epidemiology