 So where the more and more liberal the state got to substance use, the more microdosing interest you saw. No surprise, Oregon and Colorado topped the list. Both have been on the leading edge of these changes. Deborah Hassan, an epidemiologist at Columbia University, welcomed the new research. We need better epidemiology, and that is for sure, so that we really do know the extent of people's use, what circumstances they're using, how they got the drug, and what they know about what they're even taking.