title: Trajectories of cannabis use disorder: risk factors, clinical characteristics and outcomes.
abstract: To estimate cannabis use disorder (CUD) trajectory classes from ages 14 to 30 years and compare classes on clinical characteristics, risk factors and psychosocial outcomes.
  
  
  
  Four waves (T1-T4) of data from an epidemiological study of psychopathology among a regionally representative sample. Trajectory classes described risk for CUD as a function of age. The number of classes was determined by model fit.
  
  
  
  Participants were selected randomly from nine high schools in western Oregon, USA.
  
  
  
  The sample included 816 participants [age at T1 mean = 16.6, standard deviation (SD) = 1.2; 44% male; 8% non-white].
  
  
  
  Participants completed diagnostic interviews, Child Trauma Questionnaire, Social Adjustment Scale and items adapted from the Wisconsin Manual for Assessing Psychotic-Like Experiences.
  
  
  
  There were three CUD trajectory classes (Lo-Mendell-Rubin likelihood ratio test < 0.001): (1) persistent increasing risk; (2) maturing out, with increasing risk then decreasing risk; and (3) stable low risk. The persistent increasing class had later initial CUD onsets (η2= 0.16, P < 0.001) and greater cumulative CUD durations (η2= 0.26, P < 0.001). Male sex [odds ratio (OR) = 2.57, P = 0.018], externalizing disorders between ages 24 and 30 years (OR = 2.64, P < 0.001) and psychotic experiences during early adulthood (Cohen's d = 0.44, P = 0.016) discriminated between the persistent increasing and the maturing-out classes.
  
  
  
  Evidence suggests three distinguishable types of trajectory for development of cannabis use disorder starting in early teens: (1) persistent increasing risk; (2) maturing out, with increasing risk then decreasing risk; and (3) stable low risk.
authors: Oregon Research Institute, Eugene, OR, USA.|University of Oregon, College of Education, Eugene, OR, USA.
authors: Derek B
authors: DB
authors: Kosty
authors: Oregon Research Institute, Eugene, OR, USA.|University of Oregon, College of Education, Eugene, OR, USA.
authors: John R
authors: JR
authors: Seeley
authors: Oregon Research Institute, Eugene, OR, USA.
authors: Richard F
authors: RF
authors: Farmer
authors: University of Oregon, College of Education, Eugene, OR, USA.
authors: Joseph J
authors: JJ
authors: Stevens
authors: Oregon Research Institute, Eugene, OR, USA.
authors: Peter M
authors: PM
authors: Lewinsohn
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D002189:Marijuana Abuse / Q000453:epidemiology* / Q000523:psychology*; D009922:Oregon / Q000453:epidemiology; D012307:Risk Factors; D055815:Young Adult
keywords: Adolescence; adulthood; cannabis use disorder; marijuana; outcomes; risk factors; trajectories