Key Points
- A new study finds that rates of marijuana use and addiction have gone up in states that have recently legalized the drug.
- The problem was most severe for those over age of 26, with cases of addiction rising by a third.
- The findings complicate the debate around legalization.
Cannabis use disorder, also known as CUD or cannabis/marijuana addiction, is a psychological disorder described in DSM 5 as "the continued use of cannabis despite clinically significant impairment." This includes people being unable to cut down on their usage despite wanting to, those who often use it despite finding it severely impairs their ability to function, or those who are putting themselves in danger to secure access to the drug.
While an understanding that marijuana can be addictive has existed for some time, and the image of the pothead who smokes so much they can hardly function is prevalent in our society, the effects of legalization on addiction rates have somehow gone understudied until now. Importantly, previous studies had failed to consider usage rates amongst populations over the age of 25.
In the new study, published in JAMA Psychiatry, focused on self-reported data on monthly drug use in four states where marijuana is now legal, Colorado, Washington, Alaska, and Oregon, from both before and after the drug was legalized in each state and compared it to others which have not yet legalized.
The data gave insights into the drug use habits of the respondents and specifically gave information about if they had smoked at all in the last month, the frequency of their drug use, and if they had ever had issues with how much they were using drugs.The researchers ultimately considered the responses of 505,796 individuals.
The increase in cannabis usage they found was considerable. The number of respondents over the age of 26 who claimed to have used the drug in the last month went up by 23% compared with their counterparts in states that have yet to legalize. Abuse of the drug by this group rose by 37%. Teen usage rose by 25%, and addiction rates rose as well. This increase was small, though, and the authors have suggested it may be due to an unknown factor. The rate of usage or abuse for respondents between the ages of 18 and 25 did not increase at all.
After breaking the results down by demographics, the primary finding held; adults over the age of 26 are using marijuana more often when it is legalized, and they are starting to use it too much.
As in any study where findings are self-reported, the exact numbers you see here should be taken with a grain of salt. They could be slightly higher or lower. As this study relies on people self-reporting their usage of a drug that is still illegal in many places, it is very possible that the apparent spike in addiction rates is caused by more accurate reporting, as people who live in an area where pot is still illegal may be less likely to report smoking it every day.
And it should be repeated a thousand times over that correlation and causation are not the same thing. There could be some unknown factor causing these increases in each case.
Despite these qualifications, the study is still useful in giving us a general sense of what may happen in states that have yet to legalize.
Despite these qualifications, the study is still useful in giving us a general sense of what may happen in states that have yet to legalize.