In recent years, there have been important legislative changes in many countries regarding the use of cannabis for medicinal and/or recreational purposes, which have facilitated access to it. Uruguay, Canada and some of the US states are the only jurisdictions that have legalised recreational consumption, applying different legislative models. The aim of this review is to analyse the effects that the legalisation of recreational cannabis has had on its use and its consequences. In general, the evidence accumulated to date indicates that the legalisation of cannabis has been associated with a decrease in the price of the substance, higher concentration of THC (potency), greater diversity of presentations for consumption, lower risk perception and an increase in consumption in adults and moderately in adolescents (even though it is illegal for them to consume), as well as an increase in the adverse consequences derived from cannabis consumption on public health. There has been a decrease in drug-related arrests, but the illegal market continues to be frequently used. No increase in the demand for treatment due to cannabis consumption has been detected. Therefore, these legislative changes have so far failed to achieve their main objectives, which were to suppress the illegal market and protect the most vulnerable groups, while on the contrary, they seem to imply an increase in some of the negative aspects associated with cannabis consumption. However, taking into account that most of these legislative changes have entered into force relatively recently, a longer follow-up period is required to be able to draw definitive conclusions.
En los últimos años se han producido importantes cambios legislativos en numerosos países respecto al consumo de cannabis con fines medicinales y/o recreativos, que han facilitado su accesibilidad. Actualmente, Uruguay, Canadá y algunos estados de EE.UU. han legalizado el consumo recreativo, aplicando distintos modelos legislativos. El objetivo de la presente revisión es analizar los efectos que ha tenido la legalización del cannabis recreativo sobre su consumo y sus consecuencias. En general, las evidencias indican que la legalización se ha asociado a un descenso en el precio, mayor concentración de THC (potencia), mayor diversidad de presentaciones para su consumo, una menor percepción de riesgo y un incremento en el consumo en adultos y de forma moderada en adolescentes (aunque sea ilegal el consumo para ellos), así como un aumento de las consecuencias adversas derivadas del consumo en la salud pública. Se ha producido un descenso en los arrestos relacionados con el consumo, pero el mercado ilegal sigue utilizándose de forma habitual. No se ha detectado un incremento de la demanda de tratamiento por este consumo. Por el momento, estos cambios legislativos no han conseguido alcanzar sus objetivos principales que eran suprimir el mercado ilegal y proteger a los grupos más vulnerables, mientras que, por el contrario, parecen implicar un incremento de algunos aspectos negativos asociados al consumo de cannabis. Sin embargo, teniendo en cuenta que la mayoría de estos cambios legislativos han entrado en vigor hace relativamente poco tiempo, se requiere un periodo de seguimiento mayor para poder extraer conclusiones definitivas.