HealthDay (2/14, Mozes) reports that according to a study published online in Neurology, "[m]ultiple sclerosis (MS) patients who smoke marijuana in search of symptom relief are more likely to suffer cognitive shortfalls and mood disorders." Omar Ghaffar, M.D., and Anthony Feinstein, Ph.D., of the University of Toronto, "assessed the experience of 140 Toronto-based MS outpatients, 10 of whom had smoked the drug at least once in the previous month, and were considered regular marijuana users." The researchers found that "MS patients who used marijuana...perform[ed] 50 percent slower on tests tracking information-processing speed, and were more likely than nonusers to have a mental disability of some kind."

        According to the authors, while "a greater proportion of cannabis users met DSM-IV [Diagnostic and Statistical Manual of Mental Disorders] criteria for any psychiatric diagnosis (c2=4.2, P=0.04), this analysis could not determine causality," MedPage Today (2/14, Neale) adds.

        WebMD (2/14, Hitti) quotes Feinstein as saying that "this is important information because a significant minority of people with MS smokes marijuana as a treatment for the disease."