title: Maternal cigarette smoking during pregnancy predicts drug use via externalizing behavior in two community-based samples of adolescents.
abstract: OBJECTIVE
  Prenatal exposure to maternal cigarette smoking (PEMCS) is associated with a higher probability of substance use in adolescence. We explore if externalizing behavior mediates this relationship, while controlling for a number of potential covariates of this mediation process.
  
  
  METHODS
  We used data obtained in two geographically distinct community samples of adolescents. The first (cross-sectional) sample consisted of 996 adolescents (12-18 years of age) recruited from the Saguenay Youth Study (SYS) in Canada (47% with PEMCS). The second (longitudinal) sample consisted of 1141 adolescents (49% with PEMCS) from the Northern Finland Birth Cohort (NFBC1986). In both samples, externalizing behavior and substance use were assessed during adolescence. In the NFBC1986 cohort, externalizing behavior was also assessed in childhood.
  
  
  RESULTS
  In both populations, PEMCS is associated with a higher likelihood of adolescent drug experimentation. In the NFBC1986 cohort, exposed (versus non-exposed) adolescents experiment with an extra 1.27 [B = 0.24, 95% confidence intervals (CI) = 0.15, 0.33 P < 0.001] drugs. In the SYS cohort, a clear protective effect of not being exposed is shown: non-exposed (versus exposed) adolescents are 1.5 times [B = -0.42, 95% CI = -0.75, -0.09, P = 0.013] less likely to take drugs. These associations between PEMCS and drug experimentation remain in the multivariate and mediational analyses.
  
  
  CONCLUSIONS
  Prenatal exposure to maternal cigarette smoking appears to be associated with a higher probability of experimenting with drugs during adolescence, both directly and indirectly via externalizing behavior and the number of peers reported as using drugs.
authors.affiliation: Hatos Center for Neuropharmacology and Semel Institute for Neuroscience & Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.
authors.forename: Shahrdad
authors.initials: S
authors.lastname: Lotfipour
authors.forename: Eamonn
authors.initials: E
authors.lastname: Ferguson
authors.forename: Gabriel
authors.initials: G
authors.lastname: Leonard
authors.forename: Jouko
authors.initials: J
authors.lastname: Miettunen
authors.forename: Michel
authors.initials: M
authors.lastname: Perron
authors.forename: G Bruce
authors.initials: GB
authors.lastname: Pike
authors.forename: Louis
authors.initials: L
authors.lastname: Richer
authors.forename: Jean R
authors.initials: JR
authors.lastname: Séguin
authors.forename: Suzanne
authors.initials: S
authors.lastname: Veillette
authors.forename: Marjo-Riitta
authors.initials: MR
authors.lastname: Jarvelin
authors.forename: Irma
authors.initials: I
authors.lastname: Moilanen
authors.forename: Pirjo
authors.initials: P
authors.lastname: Mäki
authors.forename: Tanja
authors.initials: T
authors.lastname: Nordström
authors.forename: Zdenka
authors.initials: Z
authors.lastname: Pausova
authors.forename: Juha
authors.initials: J
authors.lastname: Veijola
authors.forename: Tomáš
authors.initials: T
authors.lastname: Paus
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior; D002170:Canada / Q000453:epidemiology; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D007389:Internal-External Control; D008297:Male; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000453:epidemiology*; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology*; D019966:Substance-Related Disorders / Q000453:epidemiology*
keywords: Addiction; adolescence; attention deficit hyperactivity disorder; drug experimentation; externalizing behavior; maternal smoking; tobacco exposure