Marijuana won't make you dumb, but it does make you forget words according to a new study. Researchers found that for every half decade, one or two users on average remembered one word fewer from a list of 15, Live Science reports.

The study, which was published in the journal JAMA Internal Medicine, featured more than 5,000 adults between the ages of 18 and 30 who were already enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) study. During a series of follow ups, they were asked if they used the substance within the last month. At the 25 year mark, participants took a cognitive test which measured verbal memory, processing speed and decision making ability.

After adjusting for outside factors like substance abuse and depression, researchers found that longtime users performed the worse in all three tests. However, the only link between marijuana and verbal memory could be summed up to chance.