title: Externalizing behaviors as predictors of substance initiation trajectories among rural adolescents.
abstract: OBJECTIVE
  The purpose of the current study was to investigate the influence of externalizing behaviors on substance initiation trajectories among rural adolescents over a 42-month period.
  
  
  METHODS
  Data were obtained from 198 rural adolescents (105 boys, 93 girls) who were participating in a longitudinal study. At the baseline assessment, subjects were on average 12.3 years of age.
  
  
  RESULTS
  Controlling for gender, higher baseline levels of externalizing were associated with a greater number of substances initiated over time. The initiation trajectory was curvilinear. Girls, compared with boys, reported a lower number of substances initiated at baseline, a greater linear growth trajectory, and a deceleration of growth over time.
  
  
  CONCLUSIONS
  The influence of adolescent externalizing behaviors on baseline levels and growth trajectories of substance initiation and the utility of latent growth curve modeling in the study of longitudinal change are discussed.
authors.affiliation: Partnerships in Prevention Science Institute, Iowa State University, Ames, Iowa 50010-8296, USA. catheri@iastate.edu
authors.forename: Catherine J
authors.initials: CJ
authors.lastname: Lillehoj
authors.forename: Linda
authors.initials: L
authors.lastname: Trudeau
authors.forename: Richard
authors.initials: R
authors.lastname: Spoth
authors.forename: Stephanie
authors.initials: S
authors.lastname: Madon
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior / Q000523:psychology*; D000374:Aggression; D002648:Child; D005260:Female; D006791:Hostility; D006801:Humans; D007604:Juvenile Delinquency; D008137:Longitudinal Studies; D008297:Male; D012307:Risk Factors; D012424:Rural Population; D019966:Substance-Related Disorders / Q000523:psychology*