The association between recreational cannabis commercialization and cannabis exposures reported to the US National Poison Data System

Abstract

Background and Aims Recreational cannabis has been legalized in 11 states and District of Columbia (DC) in the United States. Among these, 10 states further permitted retail sale to provide a legal supply to adults. This study examined the associations of cannabis exposures with recreational cannabis legalization and commercialization. Design Secondary data analysis of state‐quarter level cannabis exposures during 2010–17 in the United States. Linear regressions with a difference‐in‐differences design were used to compare pre‐ and post‐legalization trends in states that legalized recreational cannabis to contemporaneous trends in states that did not legalize recreational cannabis. Setting United States, including all 50 states and DC. Cases Cannabis exposures reported to the US National Poison Data System. Measurements The primary outcome was state age‐adjusted cannabis exposures reported to the US National Poison Data System per 1 000 000 population per quarter. The two policy variables of interest included (1) the enactment of recreational cannabis legalization (i.e. removing penalties for adults’ possession of cannabis in a small amount for recreational use) and (2) the initiation of recreational cannabis commercialization (i.e. providing a legal supply of cannabis to adults through licensed dispensaries). Findings The association between a state's enactment of recreational cannabis legalization and its changes in cannabis exposures was statistically non‐significant overall. After controlling for recreational cannabis legalization, however, the initiation of recreational cannabis commercialization was associated with 5.06–5.80 more exposures per 1 000 000 population per quarter (67–77% increase relative to the pre‐legalization average), depending on the composition of comparison states. The increase associated with commercialization was higher among minors than adults (7.97–9.53 versus 3.83–4.21 more exposures), higher among males than females (6.16–7.56 versus 3.76–3.91 more exposures) and higher among exposures with medical consequences than those without medical consequences (4.09–4.79 versus 0.97–1.01 more exposures). Conclusion An increase in cannabis exposures reported to the US National Poison Data System was observed following recreational cannabis commercialization in the United States.

Evaluation of State Cannabis Laws and Rates of Self-harm and Assault

“…This finding is consistent with previous research reporting that increases in cannabis consumption were associated with laws permitting medical dispensaries but not medical laws alone, 35 and increases in poison control center calls for cannabis exposures were associated with laws permitting recreational dispensaries but not recreational laws alone. 38 Unlike homegrown cannabis sources, dispensaries imply opportunities for large-scale, profit-driven commercial markets; greater exposure to advertising; and greater access to diverse, rapidly evolving, higher-potency products. 1 , 37 In this study, the absence of dose-related product restrictions among states with recreational dispensaries was associated with larger increases in violent injuries.…”

“…The exposure was a categorical variable reflecting the degree of cannabis commercialization in each state-month. We classified each state and month based on the type of law (medical or recreational) and the availability of dispensaries (commercialization) as follows 35 , 37 , 38 : (1) no cannabis legalization law (reference category), (2) medical only without dispensaries, (3) medical only with dispensaries, (4) recreational without dispensaries, and (5) recreational with dispensaries.…”

Impacts of Canada's cannabis legalization on police‐reported crime among youth: early evidence

“…Most research on cannabis legalization worldwide has focused on assessments of cannabis use prevalence, and it rarely evaluates outcomes of actual cannabis-related harms or benefits. Of those studies evaluating cannabis legalization's potential harms or benefits to youth, most have focused on harms, with results indicating legalization-associated increases in (i) child and youth cannabis exposures reported to poison control centers in the US [20,21]; (ii) prevalence of cannabis-use disorders among adolescents in recreational cannabis law (RCL) states versus non-RCL states in the US [22]; and (iii) youth presentations to emergency department settings for International Classification of Diseases 10th Revision (ICD-10) cannabis-use disorder or cannabis poisoning conditions (Callaghan, Sanches, Vander Heiden, Asbridge, and Kish, unpublished data, 2020). In this regard, our study provides initial evidence of potential counterweight benefits by showing that the implementation of Canada's Cannabis Act was associated with substantial reductions in youth cannabis-related involvement with the police…”

Commentary on Shi & Liang (2020): Has cannabis legalization increased acute cannabis‐related harms?

“…One of the major concerns of those who oppose cannabis legalization in the United States is that it will increase cannabis-related harm, such as acute adverse effects of intoxication. Shi & Liang assess these concerns by comparing trends in calls to the US National Poison Data System between 2010 and 2017 in US states that either did or did not (i) legalize cannabis use and (ii) legalize retail sales of cannabis [1]. They found that legalizing cannabis use did not increase the number of calls, whereas the legalization of commercial cannabis sales did.…”

“…These effects include: increased accidental ingestions of cannabis products (gummies and extracts) by children; unpleasant psychological experiences in adults receiving larger than intended doses of tetrahydrocannabinol (THC); and a new syndrome, cannabis hyperemesis syndrome, in heavy daily cannabis users .One of the major concerns of those who oppose cannabis legalization in the United States is that it will increase cannabis‐related harm, such as acute adverse effects of intoxication. Shi & Liang assess these concerns by comparing trends in calls to the US National Poison Data System between 2010 and 2017 in US states that either did or did not (i) legalize cannabis use and (ii) legalize retail sales of cannabis [1]. They found that legalizing cannabis use did not increase the number of calls, whereas the legalization of commercial cannabis sales did.…”