A young adult’s proximity to the location of medical marijuana dispensaries appears to be associated with a higher likelihood of marijuana use, with storefront advertising having the strongest influence on behavior. A RAND Corporation study examining trends in Los Angeles County drew this conclusion and is published online in the journal Addiction. “Our findings suggest that as the marijuana retail outlets become more visible and more numerous, they may influence the way that young adults perceive and use marijuana,” study lead author Regina Shih, a RAND senior behavioral scientist, said in a news release.