Just Where Exactly did that 9% Dependence Figure Come From

2014-01-27-drew_hart_cnn-thumbWe recently attended a screening of the relatively supportive documentary WEED, by Dr. Sanjay Gupta. It cites, and spends a great deal of time repeating the often cited statistic that 9% of marijuana users become addicted to marijuana. Likewise, today’s paper includes an Op-Ed by Kevin Sabet of the prohibitionist group Project SAM that repeats this dubious claim. If you hear that figure and think that it sounds high, you’re right. Here’s an excellent piece by doctor Sunil Aggarwal explaining the faulty science behind it.

The truth is that this study was done in 1994 by the anti-drug government body NIDA, and involved asking self reported “cannabis users” a series of questions like “do you often spend a long time on activities necessary to get the substance, taking the substance, or recovering from its effects?” If people answered yes, they were coded as cannabis dependent, whether or not they considered themselves dependent on cannabis. Even more importantly, people who infrequently used marijuana would be much less likely to identify themselves as cannabis users, especially in the early 90’s when it was much more strongly stigmatized than it seems to be today. Let’s get rid of this particular piece of “data” when we talk about marijuana.