Global health. The current scenario and future perspectives

214 At some point during this period, 21 states had passed a law allowing therapeutic use of cannabis. An analysis was carried out with a division into two groups: one group consisting of all studies conducted in states before passing the law on therapeutic use of cannabis and another group consisting of studies conducted after approval of the law. The results are presented in Table 3: Tabla 3. Table 3: Adolescent marijuana use in 48 contiguous US states between 1991 and 2014. Adjusted Prevalence Adjusted Odds Ratio p-value Before Law After Law All grades* 16.25% 15.45% 0.92 (0.82- 1.04) 0.185 8 th grade 8.14% 6.05% 0.73 (0.63- 0.84) < 0.0001 10 th grade 17.94% 18.27% 1.02 (0.90- 1.11) 0.738 12 th grade 22.68% 22.02% 0.96 (0.84- 1.10) 0.581 Source: Hasin, D. S., Wall, M., Keyes, K. M., Cerdá, M., Schulenberg, J., O’Malley, P. M., Galea, S., Pacula, R., Feng, T. (2015). Medical marijuana laws and adolescent marijuana use in the USA from 1991 to 2014: Results from annual, repeated cross-sectional surveys. The Lancet Psychiatry . https://doi.org/10.1016/S2215-0366 (15)00217-5. As observed, the prevalence of marijuana use globally – combining all three grades – before approving the law was 16.25% and this decreased (not significantly) to 15.45%. However, a statistically significant decrease is observed among eighth-grade students (from 8.14% to 6.05%). There are no significant changes in the other two grades. In summary, legislative changes regarding therapeutic use of cannabis are not associated with an increase in recreational marijuana use among the studied population. A third situation relates to new regulatory frameworks regarding the production and commercialization of marijuana for recreational use. Legalization in this direction has occurred only in two countries, Uruguay