Cannabis use might not have actually doubled. According to your link, "The percentage of Americans who reported using marijuana in the past year..."
The amount of people reporting increased. It is difficult to tell if actual use increased or if people are just more likely to admit they use it because of decreasing taboos.
The amount of people reporting increased. It is difficult to tell if actual use increased or if people are just more likely to admit they use it because of decreasing taboos.