Is it a worse idea to use marijuana and alcohol together than alone? A study published in May and picked up by Scientific American has answered that question for what scientists say is the first time. Researchers write in Alcoholism: Clinical & Experimental Research that no study has previously "directly compared those who use cannabis and alcohol simultaneously versus concurrently (i.e., separately) in the adult general population." What they found: People who both smoke marijuana and drink alcohol are twice as likely to indulge in both at the same time, with a press release stating they "had the heaviest drinking patterns in terms of quantity and frequency." And that simultaneous use roughly doubles their odds of driving drunk over those who were just drinking, according to data from National Alcohol Surveys of more than 8,600 people in 2005 and 2010.
Partaking in both alcohol and pot simultaneously also doubles their odds of engaging in behavior that leads to negative social consequences (think arrests, work problems, fights, etc.). What study author Meenakshi S. Subbaraman would like to see come out of her research: that "as the cannabis industry continues to grow, manufacturers will consider some sort of warning label related to increased risks when mixing alcohol and cannabis." Scientific American also points to a second study, published in the spring in Molecular Psychiatry, that exposed another downside to marijuana use. It found, at least among chronic pot smokers, users are more likely to remember things incorrectly, even if they've abstained from using for a month, compared to people who don't smoke at all. (Pot smokers also fail more courses, especially this type.)