Outcomes associated with scheduling or up-scheduling controlled substances.

Abstract Background Many nations place drugs into various “schedules” according to their risk of abuse and/or recognized medical value that vary in terms of their restrictions. To mitigate diversion or abuse, drugs sometimes get rescheduled or are scheduled for the first time. Until now, there have not been efforts to integrate lessons from across the range of such past events. Methods and data We searched for peer-reviewed evaluations of instances of (re-)scheduling drugs in the United States after 1969 and a comparably large set of instances from other countries. Those 109 articles were supplemented by 30 others found in other ways but not meeting those search criteria (e.g., because the information on rescheduling was a minor part of a more general article). Findings Findings are reported for many outcomes and with diverse measures over different timelines, making standardization of outcomes difficult. For more than half of the events for which quantitative outcomes were reported, there were declines in use-related measures by at least 40 percent. It is common for there to be reports of increases in indicators pertaining to other substances, sometimes more dangerous but sometimes less dangerous; overall, substitution appears to occur, but be partial. Conclusion Scheduling and up-scheduling can – though does not always – have substantial effects on a range of outcomes. Substitution to other substances is a possibility and so should be anticipated.