For the study, Otto Simonsson together with other colleagues analyzed data from an online survey of 2822 participants. The group was chosen using a methodology that allowed the population to reflect the rest of US adults in terms of age, sex, and ethnicity. Out of the group, 613 of them acknowledged consuming psychedelics at least once. They were then asked if what they consumed was cocaine, cannabis, pain relievers, MDMA, PCP, tobacco, or inhalants at least once, as well as how many cigarettes they consumed and how old they were when they first drank alcohol.