Vaping-specific nicotine dependence across days among a national sample of US young adults who vape.

Introduction: Vaping has increased among young adults (YAs), and nicotine dependence prevalence has increased among YAs who vape (YAV), in the U.S. Research on nicotine dependence symptoms (NDS) among YAV remains limited, and accurately measuring NDS and their severity remains a challenge. To date, no research has considered day-to-day NDS, as previous research focuses on retrospective measures.

Methods: Daily data came from the Monitoring the Future (MTF) Vaping Supplement; out of 1,244 YAs, we analyzed data from 150 (Mage=19 (SE=0.44); 71.2% non-Hispanic white; 57.8% male) who vaped nicotine at least once during 14 daily surveys (n=882 nicotine vaping days). The vaping-specific Hooked on Nicotine Checklist measured NDS on nicotine vaping days. Dichotomous and count measures of NDS were used at the day and aggregated to the person level. Descriptive analyses and multilevel regression models were estimated. Weights ensured generalizability and adjusted for attrition.

Results: Any NDS were reported on 64.5% of nicotine vaping days (average 1.93 symptoms); 43.3% of nicotine vaping days had more than 1 NDS. Results across persons (rather than days) showed any NDS on 53.8% of nicotine vaping days, and 45.4% YAs reported between 1 and 2 symptoms per vaping day; 23.3% reported 2+ symptoms on average. Multilevel models showed nontrivial variance across days and persons in NDS, and regular vaping at baseline predicted NDS.

Conclusions: Vaping-specific NDS varied across days and persons for any NDS and NDS severity. Future research should consider daily NDS fluctuations, identifying factors that confer risk to inform NDS prevention and treatment among YAV.

Implications: NDS and its severity varied across days and persons, demonstrating the utility of daily data. The results were generally similar for experiencing any NDS and for NDS severity, but there was slightly more variability across days for any NDS. Intervention and treatment strategies could utilize approaches that identify and address daily symptoms to help curb nicotine dependence. Future research and treatment efforts should also consider the immediate contexts and potential factors that explain particularly elevated NDS on a given day.