Surprise, surprise: If we legalize weed, more people toke up.

According to a new study in Addiction, cannabis consumption jumps about 24% after it’s legalized for recreational or adult-use. The study drew on survey responses from 3,421 (so close!) participants, including 111 twins, who resided in legal and non-legal states.

Nearly every US state, including Washington, DC, and Puerto Rico, were included in the study, CNN reported. The longitudinal study specifically assessed how consumption behaviors changed after 2014, when Washington state and Colorado first began selling adult-use weed. 

While it may seem obvious to the average stoner, the twins part of the study provides the most powerful evidence that legalization — and only legalization — is the primary factor influencing increased cannabis consumption. Since twins are, for the most part, genetically identical, genes shouldn’t determine if someone started toking up more.

The average weed use increase was slightly lower for twins, however. Whereas most legal states saw about a 24% jump in cannabis consumption, among twins that figure was roughly 20%. While not an exact match, it was close enough for the researchers to conclude that, yes, legalization increases cannabis use.

“Because that 20% estimate is from the analysis controlling for measured and unmeasured variables, it is the most precise estimate of the causal influence of cannabis legalization on cannabis use,” Stephanie Zellers, the study’s lead author, told CNN.

Zellers, as well as many of the study’s participants, hailed from Minnesota. Minnesota began medical cannabis sales in 2014 — the same year Colorado and Washington began adult-use sales — though the state has not yet officially legalized recreational weed. Funny enough, Minnesota’s Republicans accidentally legalized THC-rich weed edibles for recreational use in July, which have been flying off the shelves ever since.

In other words: Yes, legalizing weed results in more adults consuming cannabis. But keep in mind that multiple studies have shown that legalization does not lead to more minors getting high. In fact, data from Colorado suggests legalization lowers teen use rates.

Other studies indicate cannabis legalization also lowers opioid abuse, alcohol consumption, and crime rates while boosting employment and local economies.

So, stick that in your pipe and smoke it, SAM. 

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