title: Frequent marijuana use is associated with greater nicotine addiction in adolescent smokers.
abstract: BACKGROUND
  Marijuana and tobacco are the substances used most commonly by adolescents and co-occurring use is common. Use of one substance may potentiate the addictive properties of the other. The current study examined the severity of nicotine addiction among teen smokers as a function of co-occurring marijuana use.
  
  
  METHODS
  Participants were 165 adolescents (13-17 years old) who reported smoking at least 1 cigarette per day (CPD) in the past 30 days. General linear models examined the association of marijuana use with multiple measures of nicotine addiction including the Modified Fagerström Tolerance Questionnaire (mFTQ), Hooked on Nicotine Checklist (HONC), ICD-10, and the Nicotine Dependence Syndrome Scale (NDSS).
  
  
  RESULTS
  The adolescent sample (mean age=16.1 years, SD=0.95) averaged 3.0 CPD (SD=3.0) for 1.98 years (SD=1.5). Most (79.5%) also smoked marijuana in the past 30 days. In models controlling for age, daily smoking status, and years of tobacco smoking, frequency of marijuana use accounted for 25-44% of the variance for all four measures of adolescent nicotine dependence.
  
  
  CONCLUSIONS
  Marijuana use was associated with greater reported nicotine addiction among adolescent smokers. The findings suggest a role of marijuana in potentiating nicotine addiction and underscore the need for treatments that address both smoked substances.
authors.affiliation: Division of Adolescent Medicine at the University of California, San Francisco, San Francisco, CA, USA. Electronic address: RubinsteinM@peds.ucsf.edu.
authors.forename: Mark L
authors.initials: ML
authors.lastname: Rubinstein
authors.affiliation: Division of Adolescent Medicine at the University of California, San Francisco, San Francisco, CA, USA. Electronic address: RaitM@peds.ucsf.edu.
authors.forename: Michelle A
authors.initials: MA
authors.lastname: Rait
authors.affiliation: Stanford Prevention Research Center at Stanford University, Stanford, CA, USA. Electronic address: Jpro@stanford.edu.
authors.forename: Judith J
authors.initials: JJ
authors.lastname: Prochaska
mesh_terms: D000293:Adolescent; D016739:Behavior, Addictive / Q000175:diagnosis* / Q000453:epidemiology; D015897:Comorbidity; D059026:Diagnostic Self Evaluation; D005260:Female; D006801:Humans; D008297:Male; D008385:Marijuana Smoking / Q000453:epidemiology*; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D014029:Tobacco Use Disorder / Q000175:diagnosis* / Q000453:epidemiology
keywords: Adolescent; Cannabis; Marijuana; Nicotine addiction; Tobacco