Adolescent nicotine dependence symptom profiles and risk for future daily smoking

Longitudinal Trajectories of Multiple Nicotine Product Use Among Youths in the Population Assessment of Tobacco and Health Study

Importance

Multiple nicotine product use (MNPU) among youths is a significant public health concern. Much remains unknown about the patterns of MNPU in youths, including how socioecological factors influence trajectories of MNPU, which may inform targeted prevention.

Objective

To identify longitudinal trajectories of MNPU and characterize them according to socioecological factors associated with tobacco use.

Design, Setting, and Participants

This US-based longitudinal survey study used data from waves 1 (September 12, 2013, to December 14, 2014) through 4 (December 1, 2016, to January 3, 2018) of the Population Assessment of Tobacco and Health (PATH) study. Participants included 10 086 youths (aged 12-17 years) at wave 1, with follow-up data at waves 2 to 4 (assessed approximately 1 year apart) in the youth or adult data sets. Data were analyzed from January 15, 2020, to December 22, 2021.

Exposures

Socioecological factors at wave 1.

Main Outcomes and Measures

Outcome variables were days of use in the past 30 days of 4 products: cigarettes, e-cigarettes, cigars, and smokeless tobacco. Factors associated with use of the nicotine products that were collected at wave 1 included sociodemographic factors, internalizing and externalizing symptoms, living with a tobacco user, rules about tobacco use at home, conversations with parents about not using tobacco, tobacco accessibility, and exposure to advertising. Multitrajectory latent class growth analysis was used to identify distinct subgroups with similar patterns of use over time. Multinomial logistic regression models were used to investigate factors associated with class membership. Weights were applied to all data except frequencies to account for the complex survey design.

Results

Of the 10 086 youths included in the analysis, 5142 (51.2%) self-identified as male; 4792 (54.7%) were non-Hispanic White; and 5315 (50.6%) were aged 12 to 14 years. Six latent trajectory classes were identified: nonuse (8056 [78.2%]), experimentation (908 [9.8%]), increasing e-cigarette/cigarette use (359 [4.0%]), increasing cigarette/cigar use (320 [3.3%]), decreasing cigarette/e-cigarette/cigar use (302 [3.2%]), and stable smokeless tobacco/cigarette use (141 [1.6%]). Compared with the nonuse class, being older (odds ratio [OR] range, 2.54 [95% CI, 1.94-3.32] to 9.49 [95% CI, 6.03-14.93]), being female (OR range, 0.06 [95% CI, 0.03-0.14] to 0.71 [95% CI, 0.53-0.94]), living with a tobacco user (OR range, 1.43 [95% CI, 1.11-1.83] to 4.94 [95% CI, 3.43-7.13]), and having relaxed rules about noncombustible tobacco product use at home (OR range, 1.41 [95% CI, 1.02-1.94] to 3.42 [95% CI, 1.74-6.75]) were associated with classification in all the use classes. A high degree of difficulty accessing tobacco was associated with lower odds of membership in the increasing cigarette/cigar use vs nonuse classes (OR, 0.62 [95% CI, 0.40-0.98]).

Conclusions and Relevance

These survey results highlight the heterogeneity of longitudinal pathways of MNPU in US youths and suggest directions for future prevention and regulatory efforts directed at tobacco use behaviors in this population.

Adult Social Environments and the Use of Combustible and Electronic Cigarettes: Opportunities for Reducing Smoking in the 30s

INTRODUCTION

Reducing cigarette use is a major public health goal in the United States. Questions remain, however, about the potential for the social environment in the adult years-particularly in the 30s and beyond-to influence cigarette use. This study tested pathways hypothesized by the social development model to understand the extent to which social environmental factors at age 33 (eg, involvement with smokers or with physically active people) contribute to changes in cigarette use from age 30 to age 39. Both combustible and electronic cigarette use were investigated.

METHODS

Data were from the Seattle Social Development Project, a longitudinal study of 808 diverse participants with high retention. Self-reports assessed social developmental constructs, combustible and electronic cigarette use, and demographic measures across survey waves.

RESULTS

At age 30, 32% of the sample reported past-month cigarette use. Using structural equation modeling, results showed high stability in cigarette use from age 30 to 39. After accounting for this stability, cigarette-using social environments at age 33 predicted personal beliefs or norms about smoking (eg, acceptability and social costs), which in turn predicted combustible cigarette use at age 39. Cigarette-using environments, however, directly predicted electronic cigarette use at age 39, with no significant role for beliefs about smoking.

CONCLUSIONS

Cigarette use was highly stable across the 30s, but social environmental factors provided significant partial mediation of this stability. Pathways were different for combustible and electronic cigarette use, however, with personal smoking norms playing an important role for the former but not the latter.

IMPLICATIONS

This study addresses the need for longitudinal investigation of social mechanisms and cigarette use in the 30s. Findings reinforce efforts to prevent the uptake of cigarettes prior to the 30s because, once started, smoking is highly stable. But social environmental factors remain viable intervention targets in the 30s to disrupt this stability. Addressing personal norms about smoking's acceptability and social costs is likely a promising approach for combustible cigarette use. Electronic cigarettes, however, present a new challenge in that many perceived social costs of cigarette use do not readily translate to this relatively recent technology.

Tobacco Use Trajectories in Young Adults: Analyses of Predictors Across Systems Levels

INTRODUCTION

Research is needed to examine trajectories of tobacco use beyond cigarette smoking, particularly during emerging middle young adulthood, and to identify distinct multilevel influences of use trajectories.

AIMS AND METHODS

We examined (1) tobacco use trajectories over a 2-year period among 2592 young adult college students in a longitudinal cohort study and (2) predictors of these trajectories using variables from a socioecological framework, including intrapersonal-level factors (eg, sociodemographics, psychosocial factors [eg, adverse childhood experiences, depressive symptoms, and attention-deficit hyperactivity disorder symptoms], early-onset substance use), interpersonal factors (eg, social support, parental substance use), and community-level factors (eg, college type, rural vs. urban).

RESULTS

About 64.5% were female and 65.0% were white. From age 18 to 26, 27%-31% of participants reported past 30-day use of any tobacco product. We identified four trajectory classes: Abstainers/Dabblers who never or infrequently used (89.2%); Adult users who began using frequently around age 20 and continued thereafter (5.9%); College Smokers who began using before 19 but ceased use around 25 (2.5%); and Teenage users who used during their teenage years but ceased use by 22 (1.9%). Multinomial regression showed that, compared to Abstainers/Dabblers, significant predictors (p < .05) of being (1) Adult users included being male, earlier onset marijuana use, attending public universities or technical colleges (vs. private universities), and living in urban areas; (2) College users included being male, earlier onset marijuana use, and parental alcohol or marijuana use; and (3) Teenage users included only earlier onset marijuana use.

CONCLUSION

Distinct prevention and intervention efforts may be needed to address the trajectories identified.

IMPLICATIONS

Among young adult college students, the largest proportion of tobacco users demonstrate the risk of continued and/or progression of tobacco use beyond college. In addition, specific factors, particularly sex, earlier onset marijuana use, parental use of alcohol and marijuana, and contextual factors such as college setting (type of school, rural vs. urban) may influence tobacco use outcomes. As such, prevention and cessation intervention strategies are needed to address multilevel influences.

Cigarette Smoking and Nicotine Dependence Trajectories Among Incident Adolescent Smokers

INTRODUCTION

Few interventions target adolescent cigarette smokers to prevent escalation in cigarette use or promote cessation, in part because little is known about co-developing smoking and nicotine dependence (ND). Our objectives were to: (1) estimate developmental trajectories of ND/cravings, withdrawal symptoms, the modified Fagerström Tolerance Questionnaire (mFTQ) and ICD-10 tobacco dependence in incident adolescent smokers; (2) describe concordance in number and shapes of trajectories across the four ND indicators; and (3) classify participants in each ND trajectory according to cigarette smoking trajectories.

METHODS

Data were drawn from an ongoing longitudinal investigation of 1294 grade 7 students recruited in 1999-2000 in 10 Montreal-area high schools. Group-based joint trajectory models were used to identify distinct subgroups defined by the four ND indicators, in 307 incident smokers.

RESULTS

The optimal trajectory model included five groups for ND/craving and four groups for each of withdrawal symptoms, the mFTQ and ICD-10 tobacco dependence. The four ND indicators showed similar developmental patterns and classification into smoking trajectory groups, although some discordance was observed. Smokers in the low-level decreaser group and stable low consumers who exhibited high ND were younger than those in the cigarette-low ND trajectory groups. Moderate or rapid escalators who exhibited no/low ND were less likely to have university-educated mothers and more likely to have parents who smoke.

CONCLUSIONS

Trajectories were similar across ND indicators, and generally reflected cigarette smoking trajectory shapes. Novice smokers may need education to become self-aware of developing ND symptoms, as well as to learn about alternative courses of action once ND symptoms manifest.

IMPLICATIONS

Trajectories of cigarette smoking and ND symptoms have rarely been investigated concurrently. This study provides evidence of high concordance across four distinct ND indicators in the proportion of participants with no/low-level dependence, and with high or increasing ND. Moreover, the development of cigarette smoking is concordant with ND symptom development. Interventions to prevent escalation and promote cessation should target adolescents before first puff to increase self-awareness of developing ND symptoms, as well as to learn about alternative courses of action once ND symptoms are experienced.

Ecological momentary assessment of various tobacco product use among young adults

INTRODUCTION

Young adults are at high risk for using traditional and novel tobacco products. However, little is known about daily/weekly use patterns or psychosocial triggers for using various tobacco products.

METHODS

This ecological momentary assessment (EMA) study examined timing, tobacco cravings, affect, social context, and other substance use (alcohol, marijuana) in relation to use of cigarettes, electronic nicotine delivery systems (ENDS), and any tobacco product (i.e., cigarettes, ENDS, cigars, hookah), respectively. We also examined interactions between these predictors, sex, and race/ethnicity. From a longitudinal study of 3418 18-25 year-olds from seven Georgia colleges/universities, we recruited 72 reporting current tobacco use to participate in the 21-day EMA study; 43 participated, of which 31 completed ≥66% assessments and were analyzed. Cravings, affect, social context, and substance use were assessed daily across four four-hour windows.

RESULTS

Of the 31 participants, average age was 21.10 years (SD = 1.95), 45.2% were female, and 71.0% non-Hispanic White; 71.0% used cigarettes, 58.1% ENDS, 38.7% cigars, and 25.8% hookah (25.6% used one product, 46.5% two, 27.9% ≥ three). Predictors of cigarette use included higher anxiety, greater odds of marijuana and alcohol use, and higher boredom levels among women. Predictors of ENDS use included being non-White and greater odds of marijuana use, as well as higher tobacco cravings among women and higher boredom among men. Predictors of any tobacco product use included being non-White, higher boredom levels, and greater odds of marijuana and alcohol use.

CONCLUSIONS

Distinct interventions may be needed to address use of differing tobacco products among young adults.

Cigarette use trajectories in young adults: Analyses of predictors across system levels

BACKGROUND

Cigarette smoking escalates most in early to middle young adulthood. However, little research has examined a range of multilevel factors in relation to smoking trajectories during this time.

METHODS

We examined: 1) trajectories of cigarette smoking among 2967 US college students (aged 18-25) in a two-year, six-wave longitudinal study (using growth mixture modeling); and 2) intrapersonal- (i.e., other substance use, depressive symptoms, ADHD symptoms,); interpersonal- (i.e., adverse childhood events, social support, parental tobacco and marijuana use), and community-level (i.e., type of college, rural vs. urban setting) predictors of differing trajectories (using multinomial logistic regression).

RESULTS

We identified three trajectory classes: 1) Dabblers, who used cigarettes at one point in their life or not at all (85.6%); 2) College Onset Smokers, who began smoking regularly during the college years (6.2%); and 3) Later Onset Smokers, who began smoking during the mid- to late-20 s (8.2%). Multinomial regression (with Dabblers as the reference group) showed that predictors of being College Onset Smokers included being male (p = .031); Asian (p = .001) but not Black (p = .008; Ref: White); early onset smokers (i.e., initiation before age 15; p = .006); past 30-day users of little cigars/cigarillos (p = .024), alcohol (p < .001), and marijuana (p = .008); children of tobacco users (p = .050); and public (p = .031) or a technical college students (p < .001; Ref: private college); predictors of being Later Onset Smokers were being male (p = .019) and technical college students (p = .005).

CONCLUSIONS

Despite some young adults' smoking initiating/escalating in middle young adulthood, few risk factors were documented. This understudied period warrants greater examination to inform intervention.

Electronic Cigarettes: Exposure and Use Among Pediatric Populations

As an emerging inhalational exposure, electronic cigarettes (e-cigarettes) have rapidly gained public awareness with increasing use among adolescents and adults, leading to increased primary use by adolescents and increased secondhand exposure to emissions in infants, children, and adolescents. Although the long-term health risks for primary use and secondhand emission exposure are unknown, limited data from animal studies suggest that there is the potential for long-term lung injury and altered neurocognitive development in children with exposure to nicotine-containing aerosols. In this pediatric-focused review, we discuss the history of e-cigarettes, the demographics of adolescent users, effects on health, and current legislative efforts to protect infants, children, and adolescents from exposure.

The ABCD study of neurodevelopment: Identifying neurocircuit targets for prevention and treatment of adolescent substance abuse

Substance use disorders (SUD) can be considered developmental disorders in light of their frequent origins in substance initiation during adolescence. Cross-sectional functional magnetic resonance imaging (fMRI) studies of adolescent substance users or adolescents with SUD have indicated aberrations in brain structures or circuits implicated in motivation, self-control, and mood-regulation. However, attributing these differences to the neurotoxicological effects of chronic substance use has been problematic in that these circuits are also aberrant in at-risk children, such as those with prenatal substance exposure, externalizing disorders (such as conduct disorder), or prodromal internalizing disorders such as depression. To better isolate the effects of substance exposure on the adolescent brain, the newly-launched Adolescent Brain Cognitive Development (ABCD) study, funded by the National Institutes of Health, will follow the neurodevelopmental trajectories of over 11,000 American 9/10-year-olds for 10 years, into emerging adulthood. This study will provide a rich open-access dataset on longitudinal interactions of neurodevelopment, environmental exposures, and childhood psychopathology that confer addiction risk. The ABCD twin study will further clarify genetic versus experiential influences (e.g., substance use) on neurodevelopmental and psychosocial outcomes. Neurocircuitry thought to regulate mood and behavior has been directly normalized by administration of psychoactive medications and by cognitive therapies in adults. Because of this, we contend that ABCD project data will be a crucial resource for prevention and treatment of SUD in adolescence because its cutting-edge neuroimaging and childhood assessments hold potential for discovery of additional targetable brain differences earlier in development that are prognostic of (or aberrant in) SUD. The ABCD sample size will also have the power to illuminate how sex differences, environmental interactions and other individual differences interact with neurodevelopment to inform treatment in different groups of adolescents.

Daily Smoking and Subjective Health Complaints in Adolescence

INTRODUCTION

Using data from the Health Behaviour in School-aged Children survey, this study used a repeated cross-sectional design to examine associations between daily smoking, gender, and self-reported health complaints in five cohorts of adolescents over a 16-year period.

METHODS

Data were from nationally representative cohorts of 15-year-old youth in Norway in 1993/1994, 1997/1998, 2001/2002, 2005/2006, and 2009/2010 (n _total = 7761). Dependent variables were psychological, somatic, and total health complaints. A mixed GLM model examined main and interaction effects of smoking (daily, intermittent, nonsmoking), year, and gender in predicting complaints. Time periods were segmented to compare trends across smoking groups in specific periods.

RESULTS

Prevalence of daily smoking declined from 15.5% (1993/1994) to 6.0% (2009/2010). All health complaint scores were significantly higher for smokers and for girls (vs. boys). Smoking status by year interactions were significant for all complaint variables during the period of sharpest decline of daily smoking prevalence (2001/2002-2005/2006), with daily smokers experiencing increases in health complaints while intermittent and nonsmokers did not. Smoking status by gender interactions were significant for all health complaint variables, indicating that the main effect for gender (females higher) was even stronger among smokers compared with nonsmokers. Using year as unit of analysis, the size of mean differences between daily smokers and intermittent/nonsmokers in total complaints was significantly negatively correlated with daily smoking prevalence (-.963, n = 5, p < .01).

CONCLUSIONS

As prevalence of daily smoking declined, daily smokers reported higher levels of complaints, suggesting increasing health problems within this group. Girls who smoke daily had particularly elevated levels of complaints.

IMPLICATIONS

This study indicates that the relationship between daily smoking and concurrent health symptomatology in adolescents is changing over time, with higher levels of health complaints reported as overall smoking prevalence declines. To our knowledge, this finding has not previously been reported. If youth are smoking to cope with distress, pain, or other health concerns, tobacco control objectives will be increasingly difficult to achieve with adolescents. Levels of health complaints are particularly high among girls who are daily smokers. The findings suggest that restrictive measures and persuasive communications may not be sufficient tobacco prevention strategies for adolescent populations. Young smokers may need counseling and support.

Electronic cigarette use and exposure in the pediatric population

Electronic cigarette (e-cigarette) use has gained recent widespread popularity and acceptance in the general population. What effect e-cigarettes may have on pediatric health remains unknown. Although many jurisdictions have laws that prevent the sale of e-cigarettes to minors and the use of e-cigarettes in public places, infants, children, and adolescents are increasingly exposed to them. In this pediatric-focused review, we discuss the history of these devices, user demographics, known health effects, and current legislative efforts to protect minors from exposure.

Nicotine pharmacokinetics in rats is altered as a function of age, impacting the interpretation of animal model data

Several behavioral studies report that adolescent rats display a preference for nicotine compared with adults. However, age-related pharmacokinetic differences may confound the interpretation of these findings. Thus, differences in pharmacokinetic analyses of nicotine were investigated. Nicotine was administered via acute s.c. (1.0 mg base/kg) or i.v. (0.2 mg base/kg) injection to early adolescent (EA; postnatal day 25) and adult (AD; postnatal day 71) male Wistar rats. Nicotine and its primary metabolite, cotinine, and additional metabolites nornicotine, nicotine-1'-N-oxide, trans-3'-hydroxycotinine, and norcotinine were sampled from 10 minutes to 8 hours (plasma) and 2 to 8 hours (brain) post nicotine and analyzed by liquid chromatography-tandem mass spectrometry. Following s.c. nicotine, the EA cohort had lower levels of plasma nicotine, cotinine, and nicotine-1'-N-oxide at multiple time points, resulting in a lower area under the plasma concentration-time curve (AUC) for nicotine (P < 0.001), cotinine (P < 0.01), and nicotine-1'-N-oxide (P < 0.001). Brain levels were also lower for these compounds. In contrast, the EA cohort had higher plasma and brain AUCs (P < 0.001) for the minor metabolite nornicotine. Brain-to-plasma ratios varied for nicotine and its metabolites, and by age. Following i.v. nicotine administration, similar age-related differences were observed, and this route allowed detection of a 1.6-fold-larger volume of distribution and 2-fold higher plasma clearance in the EA cohort compared with the AD cohort. Thus, unlike in humans, there are substantial age differences in nicotine pharmacokinetics such that for a given nicotine dose, adolescent rats will have lower plasma and brain nicotine compared with adults, suggesting that this should be considered when interpreting animal model data.

A history of ashes: an 80 year comparative portrait of smoking initiation in American Indians and Non-Hispanic whites--the Strong Heart Study

The consequences of starting smoking by age 18 are significant. Early smoking initiation is associated with higher tobacco dependence, increased difficulty in smoking cessation and more negative health outcomes. The purpose of this study is to examine how closely smoking initiation in a well-defined population of American Indians (AI) resembles a group of Non-Hispanic white (NHW) populations born over an 80 year period. We obtained data on age of smoking initiation among 7,073 AIs who were members of 13 tribes in Arizona, Oklahoma and North and South Dakota from the 1988 Strong Heart Study (SHS) and the 2001 Strong Heart Family Study (SHFS) and 19,747 NHW participants in the 2003 National Health Interview Survey. The participants were born as early as 1904 and as late as 1985. We classified participants according to birth cohort by decade, sex, and for AIs, according to location. We estimated the cumulative incidence of smoking initiation by age 18 in each sex and birth cohort group in both AIs and NHWs and used Cox regression to estimate hazard ratios for the association of birth cohort, sex and region with the age at smoking initiation. We found that the cumulative incidence of smoking initiation by age 18 was higher in males than females in all SHS regions and in NHWs (p < 0.001). Our results show regional variation of age of initiation significant in the SHS (p < 0.001). Our data showed that not all AIs (in this sample) showed similar trends toward increased earlier smoking. For instance, Oklahoma SHS male participants born in the 1980s initiated smoking before age 18 less often than those born before 1920 by a ratio of 0.7. The results showed significant variation in age of initiation across sex, birth cohort, and location. Our preliminary analyses suggest that AI smoking trends are not uniform across region or gender but are likely shaped by local context. If tobacco prevention and control programs depend in part on addressing the origin of AI smoking it may be helpful to increase the awareness in regional differences.