The International Drug Control Conventions of 1961 and 1971 mandate WHO to make recommendations to the United Nations Secretary-General on the need for and level of international control of psychoactive substances according to the advice of its independent scientific advisory body, the ECDD.

At its forty-fifth meeting, the ECDD critically reviewed nine new psychoactive substances, comprising one synthetic cannabinoid receptor agonist (ADBBUTINACA), two benzodiazepines (adinazolam, bromazolam) four novel synthetic opioids (protonitazene, etazene, etonitazepyne, 2-methyl-AP-237) and two cathinones/stimulants (a-PiHP and 3-Methylmethcathinone). A critical review was undertaken of data on the use of each substance and its effects, so that the Expert Committee could determine whether the information available on these substances justified scheduling in the 1961 or 1971 Convention. In addition, the meeting pre-reviewed zopiclone, to determine whether the current information justified a critical review. After the Forty-fifth Meeting of the ECDD, WHO endorsed and submitted recommendations to the United Nations Secretary-General for further consideration by the Commission on Narcotic Drugs.