Attention middle-age marijuana users: you now have one more piece of ammunition to use against people who say that marijuana use is making you slow. According to a study published last year in the American Journal of Epidemiology, moderate marijuana use, both past and current, has no long-term effects on cognitive function and memory. Of the 9,000 adults around the age of 42 that were surveyed, those that had used drugs in the past (even the recent past) scored equal to or slightly better than those…