Patterns and Characteristics of Nicotine Dependence Among Adults With Cigarette Use in the US, 2006-2019

IMPORTANCE: Nicotine dependence increases the risk of persistent smoking, which is the leading preventable cause of morbidity and death. However, evidence regarding the associations of nicotine dependence with age, psychiatric conditions, and sociodemographic characteristics is limited. OBJECTIVE: To assess whether and how nicotine dependence among US adults with cigarette use varies by year, age, psychiatric comorbidities, and sociodemographic characteristics. DESIGN, SETTING, AND PARTICIPANTS: This exploratory serial cross-sectional study used data from 152 354 US community-dwelling individuals 18 years or older who participated in the 2006-2019 National Surveys on Drug Use and Health. Data analyses were conducted from January 15 to February 15, 2023. EXPOSURE: Past-month cigarette use. Past-year major depressive episode (MDE) and/or substance use disorder (SUD) based on criteria from the Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition), Text Revision. MAIN OUTCOMES AND MEASURES: Past-month nicotine dependence based on criteria from the Nicotine Dependence Syndrome Scale or the Fagerström Test of Nicotine Dependence. RESULTS: Among 152 354 adults with past-month cigarette use (54.1% male; 40.2% aged 18-34 years; 29.0% aged 35-49 years; 69.8% non-Hispanic White), the adjusted prevalence of nicotine dependence decreased from 59.52% (95% CI, 57.93%-61.10%) in 2006 to 56.00% (95% CI, 54.38%-57.60%) in 2019 (average annual percentage change [AAPC], −0.4%; 95% CI, −0.5% to −0.4%; P < .001) and among each examined age group, except for stability among those aged 18 to 25 years (AAPC, −0.5%; 95% CI, −1.4% to 0.4%; P = .27). Compared with those 50 years and older with past-month cigarette smoking, the adjusted prevalence of nicotine dependence among those aged 18 to 49 years was 32% lower for those aged 18 to 25 years (adjusted risk ratio [ARR], 0.68; 95% CI, 0.66-0.70), 18% lower for those aged 26 to 34 years (ARR, 0.82; 95% CI, 0.80-0.84), and 6% lower for those aged 35 to 49 years (ARR, 0.94; 95% CI, 0.92-0.96). The adjusted prevalence of nicotine dependence varied by age, MDE and/or SUD status, and sociodemographic characteristics. For example, by 2019, prevalence was 41.27% (95% CI, 39.21%-43.37%) among those aged 18 to 25 years and 64.43% (95% CI, 60.98%-67.74%) among those 50 years and older. Differences in nicotine dependence prevalence between those with co-occurring MDE and SUD and those without both conditions were more than 2 times larger for those 50 years and older vs those aged 18 to 49 years (eg, ages ≥50 years vs 18-25 years: 18.69 percentage point difference [83.32% vs 64.63%] vs 7.67 percentage point difference [48.88% vs 41.21%]; P < .001). CONCLUSIONS AND RELEVANCE: In this cross-sectional study, there were significant reductions in nicotine dependence prevalence from 2006 to 2019 among US adults with cigarette use and all examined subgroups 26 years and older. Adults 50 years and older (especially those with MDE and/or SUD) had the highest nicotine dependence prevalence compared with other age groups, highlighting the importance of assisting with smoking cessation efforts and addressing nicotine dependence for this older population. Evidence-based tobacco cessation strategies tailored to age and comorbidities are needed.