Modernizing methodology for the WHO assessment of substances for the international drug control conventions

The WHO Executive Board revised the guidance that governs the procedures for the WHO review of psychoactive substances for international drug control in 2010. To meet the standards defined in these guidelines, the current evaluation methodology at WHO must be an evidence-based assessment.

We describe the history of substance evaluation from 1912 to the present and the development of the evaluation methods over time including a description of the current assessment system, using reports from WHO and its predecessor, the League of Nations. Furthermore, we describe the current review system.

We found that some substances under international control were never reviewed; other substances were reviewed decades ago.

We argue that assessments do not have unlimited validity, and therefore, substances need to be re-assessed periodically, as already recommended by the Expert Committee on Drug Dependence in 1982. We propose that the evaluation time be shortened; that the influence of the route of administration and/or dosage form of the preparation is considered in the evaluation; and we recommend studying national and regional assessment systems and adopting their best practices. With this article, we make a case for the inclusion of systematic review and other methods of comprehensive analysis of substance evaluation to arrive at a process of equal rigour and quality as already applied by WHO for the development of treatment guidelines.