title: Marijuana use from adolescence to adulthood: developmental trajectories and their outcomes.
abstract: The study assesses the degree to which individuals in different trajectories of marijuana use are similar or different in terms of unconventional behavior, sensation seeking, emotional dysregulation, nicotine dependence, alcohol dependence/abuse, children living at home, and spouse/partner marijuana use at age 43.
  
  
  
  This study used a longitudinal design. The sample participants (N = 548) were first studied at mean age 14 and last studied at mean age 43.
  
  
  
  Six trajectories of marijuana use were identified: chronic/heavy users (3.6 %), increasing users (5.1 %), chronic/occasional users (20 %), decreasers (14.3 %), quitters (22.5 %), and nonusers/experimenters (34.5 %). With three exceptions, as compared with being a nonuser/experimenter, a higher probability of belonging to the chronic/heavy, the increasing, or the chronic/occasional user trajectory group was significantly associated with a greater likelihood of unconventional behavior, sensation seeking, emotional dysregulation, nicotine dependence, alcohol dependence/abuse, not having children who lived at home, and having a spouse/partner who used marijuana at early midlife. In addition, compared with being a quitter, a higher probability of belonging to the chronic/heavy user trajectory group was significantly associated with a higher likelihood of unconventional behavior, sensation seeking, emotional dysregulation, alcohol dependence/abuse, and spouse/partner marijuana use. Implications for intervention are presented.
  
  
  
  Trajectories of marijuana use, especially chronic/heavy use, increasing use, and chronic/occasional use, are associated with unconventional behavior, sensation seeking, emotional dysregulation, nicotine dependence, alcohol dependence/abuse, having children who lived at home, and spouse/partner marijuana use at age 43. The importance of the findings for prevention and treatment programs are discussed.
authors.affiliation: Department of Psychiatry, New York University School of Medicine, 215 Lexington Avenue, 15th Floor, New York, NY, 10016, USA. judith.brook@nyumc.org.
authors.forename: Judith S
authors.initials: JS
authors.lastname: Brook
authors.affiliation: Department of Psychiatry, New York University School of Medicine, 215 Lexington Avenue, 15th Floor, New York, NY, 10016, USA.
authors.forename: Chenshu
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Department of Behavioral Sciences, University of Kentucky, Lexington, KY, USA.
authors.forename: Carl G
authors.initials: CG
authors.lastname: Leukefeld
authors.affiliation: Department of Psychiatry, New York University School of Medicine, 215 Lexington Avenue, 15th Floor, New York, NY, 10016, USA.
authors.forename: David W
authors.initials: DW
authors.lastname: Brook
mesh_terms: D000293:Adolescent; D000328:Adult; D019973:Alcohol-Related Disorders / Q000453:epidemiology / Q000523:psychology*; D002188:Cannabis; D005260:Female; D006803:Human Development; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D002189:Marijuana Abuse / Q000145:classification / Q000453:epidemiology / Q000523:psychology*; D008385:Marijuana Smoking / Q000453:epidemiology / Q000523:psychology*; D009518:New York / Q000453:epidemiology; D014029:Tobacco Use Disorder / Q000453:epidemiology / Q000523:psychology*; D055815:Young Adult
keywords: Alcohol dependence/abuse; Emotional dysregulation; Nicotine dependence; Not having children living at home; Sensation seeking; Spouse/partner marijuana use; Trajectories of marijuana use; Unconventional behavior