Plusieurs auteurs consultés (Beauchesne,1988; Bertrand,1989; Solomon et Green, 1988; Caballero,1989; Glorie,1984; Nadelmann,1992) affirment que la période comprise entre 1912 et 1961 a mené à une constante intensification des contrôles, parallèlement à un élargissement des accords internationaux, passant du contrôle de la production de l'opium à une criminalisation graduelle de plus en plus de «comportements» associés aux substances désormais «illicites», autant sur le plan quantitatif que qualitatif.
A number of the other authors consulted (Beauchesne, 1988; Bertrand, 1989; Solomon and Green, 1988; Caballero, 1989; Glorie, 1984; Nadelmann, 1992) assert that the period between 1912 and 1961 led to an ongoing intensification of controls at the same time as international agreements were expanded, ranging from control of the production of opium to a gradual criminalization of increasing numbers of “behaviours” associated with substances that were now “illicit”, in both quantitative and qualitative terms.