This study sought to compare questionnaire ratings of subjective experiences after psilocybin when administered in controlled research settings vs. uncontrolled, non-research settings.
Carbonaro, T. M., Klinedinst, M., Johnson, M. W., & Griffiths, R. R. (2015). Comparative phenomenology of psilocybin experiences in research and non-research settings. Drug and Alcohol Dependence, 156, e36-e37. http://dx.doi.org/10.1016/j.drugalcdep.2015.07.1017