The US Drug Enforcement Administration issued an interim final rule in August 2020 to clarify the Farm Bill, indicating that ∆8-THC and other synthetically derived tetrahydrocannabinols were Schedule I controlled substances; however, there continues to be widespread sale and use of ∆8-THC [4, 18, 19]. Our study demonstrated a 79% increase in the rate of reported ∆8-THC exposures to US PCs from 2021 to 2022. Although most ∆8-THC exposures (52%) were treated/evaluated and released, a notable 16% were admitted to either a non-CCU or CCU. ∆8-THC exposures were commonly associated with a minor effect (39%) or moderate effect (36%), with a minority experiencing a major effect (3%).

Although ∆8-THC products are intended for use by adults, children represented more than half of exposures (30% were < 6 years old and 24% were 6–19 years old), and children < 6 years old accounted for half of non-CCU admissions and 58% of CCU admissions, as well as 28% of moderate and approximately one-third of major medical outcomes. The high proportion of hospital admissions and serious medical outcomes among young children may be attributable, in part, to the relatively greater ∆8-THC dose per body weight among pediatric exposures compared with adult exposures [20, 21]. This is likely exacerbated by young children mistaking edible ∆8-THC products for food or candy, the presence of multiple doses in one product package (some totaling hundreds of milligrams), and the delay in onset of clinical effects that allows continued consumption of the product before the child or caregivers notice that something is wrong [21, 22]. In addition, minors can readily access ∆8-THC, which is often marketed in ways that appeal to teenagers, can often be obtained without age verification, and typically costs less than ∆9-THC [6, 7, 23].

The number and characteristics of ∆8-THC exposures reported to PCs varied widely by US region. The South accounted for 70% of exposures, followed by the Midwest (22%), while the Northeast and West represented only 6% and 2%, respectively. These findings are consistent with those of a survey of selected twelfth grade students, which found that reported ∆8-THC use was higher in the South and Midwest [9]. The age distribution of exposed individuals and the reason for exposure also varied by region in our study, with children < 6 years old and the exposure reason “unintentional – general” (which represents exploratory behavior in this age group) more common in the West, while 20-59-year-olds and “abuse” more common in the Midwest and South. The proportion of exposures that were admitted to a non-CCU or CCU was lower in the West than in other regions. Likewise, the proportion of exposures associated with moderate or major effects was lower in the West than in other regions. The reasons for these variations cannot be answered by this study but represent areas of future research. Prevention strategies are different for exposures among young children associated with exploratory behavior than intentional exposures among teenagers and adults, and findings from this study suggest that target populations and the types of population-based prevention interventions may need to vary by region.

Cannabis (∆9-THC) is the most commonly used illicit drug in the world; [24] however, legal access to cannabis for recreational use has increased rapidly in the US with changes in state laws during recent years. As hypothesized, our findings showed a statistically significant lower rate of ∆8-THC exposures reported to PCs among states where medical or recreational cannabis use was legal than states where cannabis use was illegal. This is likely attributable, in part, to less market competition from ∆9-THC products in states where their use was illegal, and that ∆8-THC was likely being used as a substitute for ∆9-THC. This is consistent with studies that found a higher proportion of internet queries about ∆8-THC in states where recreational cannabis was illegal than in states where it was legal [25, 26]. This is also consistent with research that showed greater self-reported ∆8-THC use among surveyed twelfth grade students in states without cannabis legislation [9] and lower reported use of ∆8-THC by adults who lived in states with medical or recreational cannabis laws [8].

In addition, as hypothesized, there was a statistically significant lower rate of ∆8-THC exposures reported to PCs among states where ∆8-THC was banned than states where it was unregulated. This reflects the potential for regulation to reduce potentially harmful exposures and is consistent with the findings from a survey of selected twelfth grade students, who reported higher ∆8-THC use prevalence in states without ∆8-THC regulations [9]. Although, to-date, public policy efforts have focused more on ∆9-THC, our study’s findings support the need for adoption of consistent regulation of ∆8-THC across all states.