Youth e-cigarette use remains a public health concern worldwide (World Health Organization, 2019). In the United States, 10.0% of high school students and 4.6% of middle school students reported current (past-month) use of e-cigarettes in 2023 (Birdsey et al., 2023). The availability of flavors is one of the main reasons that e-cigarettes appeal to youth (Goldenson et al., 2019, Kong et al., 2015). In 2023, 89.4% of US middle school and high school students who were currently using e-cigarettes reported using flavored e-cigarettes (Birdsey et al., 2023). Among them, a substantial portion reported using flavors that produce cooling sensations, with 57.9% reporting use of flavors with “ice” or “iced” in their names (Birdsey et al., 2023).

Cooling sensations from e-cigarettes are produced by adding flavoring agents such as menthone and peppermint that produce a cool feeling in the mouth and throat upon inhalation (Brown et al., 2022, Rosbrook and Green, 2016). Moreover, synthetic flavor additives in e-liquids, such as WS-23 (2-isopropyl-N,2,3-trimethylbutyramide), also produce cooling sensations (Jabba et al., 2022, Leventhal et al., 2022). Research indicates that incorporating synthetic coolant WS-23 into e-cigarettes enhances the vaping experience (Tackett et al., 2023). Although a cooling sensation has typically been associated with menthol and mint e-cigarette flavors, it is becoming more common to incorporate cooling agents into fruit and candy-flavored liquids to produce similar sensations (e.g., strawberry freeze) (Ali et al., 2022). Given the growing ubiquity of cooling flavors in e-cigarettes, with unit sales experiencing a staggering 700% surge from 2017 to 2021 (Ali et al., 2022), it is important to consider the potential risks associated with the use of cooling flavors, particularly in relation to e-cigarette dependence among youth.

E-cigarettes typically deliver nicotine, which not only detrimentally affects brain development and cardiovascular function but also predisposes individuals to nicotine dependence (USDHHS, 2016). Existing evidence has established associations between e-cigarette dependence and nicotine exposure (Morean et al., 2018, Vogel et al., 2020). Adding a new layer of concern, the introduction of cooling flavors may mitigate the harshness of nicotine, enhancing the overall appeal and ease of use (Krishnan-Sarin et al., 2017), potentially leading to sustained use and dependence. E-cigarette dependence may also increase the frequency of e-cigarette use, making individuals more likely to transition to conventional cigarettes, drugs, and alcohol (USDHHS, 2016). Previous studies have found an association between the use of cooling flavors and more frequent e-cigarette use among adolescents (Davis et al., 2021), as well as vaping dependence measured by the modified Hooked on Nicotine Checklist among young adults (Leventhal et al., 2023). In this study, we investigated whether the use of cooling flavors is associated with e-cigarette dependence using the 4-item Patient-Reported Outcomes Measurement Information System Nicotine Dependence Item Bank for E-cigarettes (PROMIS®-E) (HealthMeasures, 2023, Morean et al., 2018), which is a recently validated and concise instrument used for evaluating youth e-cigarette dependence, derived from the PROMIS Item Bank v1.0-Smoking: Nicotine Dependence. Therefore, our study explores this association within a sample of high school students in Connecticut who use e-cigarettes. The findings can help guide flavor regulations that seek to reduce e-cigarette use and prevent e-cigarette dependence in youth.