Did Marijuana Legalization lead to increased use in Colorado? A new study has a novel answer

The study, by a former University of Colorado graduate student, looked at data on twins to answer a longstanding question.

In the decade since Colorado voters passed Amendment 64 legalizing adult use of marijuana in state law, a slew of studies have tried to estimate the impact.

They’ve looked broadly and more narrowly, and have concluded — depending on how you might read them — that legalization either did or did not lead to an increase in cannabis use.

But a new study, conducted by a former Ph.D. student in Colorado, takes perhaps the most novel approach yet and comes to the conclusion that legalization may, in fact, lead to people using marijuana more frequently.