title: Characterizing smoking topography of cannabis in heavy users.
abstract: BACKGROUND
  Little is known about the smoking topography characteristics of heavy cannabis users. Such measures may be able to predict cannabis use-related outcomes and could be used to validate self-reported measures of cannabis use.
  
  
  OBJECTIVE
  The current study was conducted to measure cannabis smoking topography characteristics during periods of ad libitum use and to correlate topography assessments with measures of self-reported cannabis use, withdrawal and craving during abstinence, and cognitive task performance.
  
  
  METHODS
  Participants (N = 20) completed an inpatient study in which they alternated between periods of ad libitum cannabis use and abstinence. Measures of self-reported cannabis use, smoking topography, craving, withdrawal, and sleep measures were collected.
  
  
  RESULTS
  Participants smoked with greater intensity (e.g., greater volume, longer duration) on initial cigarette puffs with a steady decline on subsequent puffs. Smoking characteristics were significantly correlated with severity of withdrawal, notably sleep quality and architecture, and craving during abstinence, suggesting dose-related effects of cannabis use on these outcomes. Smoking characteristics generally were not significantly associated with cognitive performance. Smoking topography measures were significantly correlated with self-reported measures of cannabis use, indicating validity of these assessments, but topography measures were more sensitive than self-report in predicting cannabis-related outcomes.
  
  
  CONCLUSIONS
  A dose-effect relationship between cannabis consumption and outcomes believed to be clinically important was observed. With additional research, smoking topography assessments may become a useful clinical tool.
authors.affiliation: Behavioral Pharmacology Research Unit, Johns Hopkins University School of Medicine, 5510 Nathan Shock Drive, Baltimore, MD 21224, USA. emcclur4@jhmi.edu
authors.forename: Erin A
authors.initials: EA
authors.lastname: McClure
authors.forename: Maxine L
authors.initials: ML
authors.lastname: Stitzer
authors.forename: Ryan
authors.initials: R
authors.lastname: Vandrey
mesh_terms: D000293:Adolescent; D000328:Adult; D016739:Behavior, Addictive; D003071:Cognition / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D002189:Marijuana Abuse / Q000503:physiopathology* / Q000523:psychology*; D008385:Marijuana Smoking / Q000503:physiopathology* / Q000523:psychology*; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D011597:Psychomotor Performance / Q000187:drug effects; D012890:Sleep / Q000187:drug effects; D013375:Substance Withdrawal Syndrome / Q000175:diagnosis / Q000523:psychology