Temporal trends in marijuana attitudes, availability and use in Colorado compared to non-medical marijuana states: 2003-11.
BACKGROUND
In 2009, policy changes were accompanied by a rapid increase in the number of medical marijuana cardholders in Colorado. Little published epidemiological work has tracked changes in the state around this time.


METHODS
Using the National Survey on Drug Use and Health, we tested for temporal changes in marijuana attitudes and marijuana-use-related outcomes in Colorado (2003-11) and differences within-year between Colorado and thirty-four non-medical-marijuana states (NMMS). Using regression analyses, we further tested whether patterns seen in Colorado prior to (2006-8) and during (2009-11) marijuana commercialization differed from patterns in NMMS while controlling for demographics.


RESULTS
Within Colorado those reporting "great-risk" to using marijuana 1-2 times/week dropped significantly in all age groups studied between 2007-8 and 2010-11 (e.g. from 45% to 31% among those 26 years and older; p=0.0006). By 2010-11 past-year marijuana abuse/dependence had become more prevalent in Colorado for 12-17 year olds (5% in Colorado, 3% in NMMS; p=0.03) and 18-25 year olds (9% vs. 5%; p=0.02). Regressions demonstrated significantly greater reductions in perceived risk (12-17 year olds, p=0.005; those 26 years and older, p=0.01), and trend for difference in changes in availability among those 26 years and older and marijuana abuse/dependence among 12-17 year olds in Colorado compared to NMMS in more recent years (2009-11 vs. 2006-8).


CONCLUSIONS
Our results show that commercialization of marijuana in Colorado has been associated with lower risk perception. Evidence is suggestive for marijuana abuse/dependence. Analyses including subsequent years 2012+ once available, will help determine whether such changes represent momentary vs. sustained effects.
Department of Psychiatry, University of Colorado Anschutz Medical Campus, Aurora, CO, United States.
Joseph
J
Schuermeyer
Department of Psychiatry, University of Colorado Anschutz Medical Campus, Aurora, CO, United States.
Stacy
S
Salomonsen-Sautel
Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, United States.
Rumi Kato
RK
Price
Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, United States.
Sundari
S
Balan
Department of Psychiatry, University of Colorado Anschutz Medical Campus, Aurora, CO, United States; Denver Health and Hospital Authority, Denver, Colorado, United States.
Christian
C
Thurstone
Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States.
Sung-Joon
SJ
Min
Department of Psychiatry, University of Colorado Anschutz Medical Campus, Aurora, CO, United States. Electronic address: joseph.sakai@ucdenver.edu.
Joseph T
JT
Sakai
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001290:Attitude; D002188:Cannabis; D002648:Child; D003120:Colorado; D003625:Data Collection; D005006:Ethnicity; D005260:Female; D006801:Humans; D008297:Male; D008385:Marijuana Smoking / Q000453:epidemiology / Q000523:psychology*; D064086:Medical Marijuana; D008875:Middle Aged; D014481:United States; D055815:Young Adult
D064086:Medical Marijuana
Cannabis; Decriminalization; Legalized marijuana; Marijuana policy; Medical marijuana