title: Heterogeneity in the composition of marijuana seized in California.
abstract: BACKGROUND
  Marijuana contains multiple cannabinoids. Most attention is given to delta-9-tetrahydrocannabinol (THC) which produces euphoria and in some cases anxiety and panic reactions. Research suggests that another cannabinoid, cannabidiol (CBD), may offset some of these effects. Thus, there is growing interest in the health consequences of the THC to CBD ratio for marijuana.
  
  
  METHODS
  Using data from over 5000 marijuana samples in California from 1996 to 2008, we examine changes in the median THC-level, median CBD-level, and median THC:CBD-ratio.
  
  
  RESULTS
  The median THC-level and median THC:CBD-ratio have dramatically increased for seizures in California, particularly north of the Mexican border.
  
  
  CONCLUSIONS
  Research on the consequences of the THC:CBD ratio should continue, especially as more attention is devoted to thinking about how to regulate marijuana for medical and recreational use. Researchers should also consider the lack of uniformity in the chemical composition of marijuana when evaluating its health effects.
authors.affiliation: Pardee RAND Graduate School, RAND Corporation, 1776 Main Street, Santa Monica, CA 90401, USA.
authors.forename: James Richard
authors.initials: JR
authors.lastname: Burgdorf
authors.forename: Beau
authors.initials: B
authors.lastname: Kilmer
authors.forename: Rosalie Liccardo
authors.initials: RL
authors.lastname: Pacula
mesh_terms: D002140:California; D002185:Cannabidiol / Q000032:analysis* / Q000494:pharmacology; D002188:Cannabis / Q000737:chemistry* / Q000145:classification; D016208:Databases, Factual; D013759:Dronabinol / Q000032:analysis* / Q000494:pharmacology; D006801:Humans; D035846:Law Enforcement; D011619:Psychotropic Drugs / Q000032:analysis* / Q000494:pharmacology
chemical_list: D011619:Psychotropic Drugs; D002185:Cannabidiol; D013759:Dronabinol