Researchers at the University of Michigan have sifted through nationwide data to determine the prevalence of different drug-related emergency room visits and (surprise, surprise!) their recently released results show that “marijuana dependence was associated with the lowest rates” of emergency room visits. NORML’s Paul Armentano has broken down the study here on Alternet: Among those surveyed, subjects that reported using cannabis were the least likely to report an ED visit (1.71 percent). Respondents…