An investigation of social and pharmacological exposure to secondhand tobacco smoke as possible predictors of perceived nicotine dependence, smoking susceptibility, and smoking expectancies among never-smoking youth

Secondhand Smoke Exposure and Smoking Prevalence Among Adolescents

Importance

Secondhand smoke is a substantial risk factor for youth health globally, including in Japan, where tobacco control policies should be reassessed.

Objective

To assess trends in the prevalence of secondhand smoke exposure among Japanese adolescents from 2008 to 2017 and to examine the association between its frequency and smoking during the study period.

Design, Setting, and Participants

This study comprised a nationally representative, self-administered, school-based, cross-sectional survey focusing on tobacco and alcohol use and related factors among students in grades 7 to 12 (ages 12-18 years) in Japan. This random sampling survey used single-stage cluster sampling. Using the national school directory, junior and senior high schools throughout Japan were randomly extracted from each regional block. All students enrolled in the sampled schools were included as participants, and school-based surveys were completed in 2008, 2012, and 2017. Data analysis was performed from January 1 to March 15, 2023.

Main Outcomes and Measures

Prevalence of secondhand smoke exposure among adolescents in Japan from 2008 to 2017 and changes in the association between secondhand smoke exposure frequency and prevalence of smoking were examined using multiple logistic regression analysis.

Results

Data were analyzed for 95 680 adolescents in 2008 (50.7% boys), 100 050 in 2012 (51.6% boys), and 64 152 in 2017 (53.9% boys). At baseline, 42.0%, 38.5%, and 34.6% of the participants were junior high school students in 2008, 2012, and 2017, respectively. Based on the 2008 surveys, 51.0% of adolescents in grades 7 to 12 were exposed to secondhand smoke in any place (≥1 day during the past 7 days), 37.2% were exposed at home, and 36.5% were exposed in public places. In 2017, 36.3% of participants were exposed to secondhand smoke in any place, 23.8% were exposed at home, and 27.0% were exposed in public places. An association between secondhand smoke exposure frequency and prevalence of smoking was observed consistently regardless of survey year, location, or pattern of exposure (adjusted odds ratios ranged from 2.29 [95% CI, 1.81-2.91] for 1-2 days at home to 11.15 [95% CI, 8.50-14.62] for 7 days in public places). Stratified analysis by higher education intention indicated that the prevalence of smoking and secondhand smoke exposure decreased but remained higher among adolescents who did not intend to pursue higher education. The association between secondhand smoke and smoking did not differ substantially between groups.

Conclusions and Relevance

In this cross-sectional study, the prevalence of secondhand smoke exposure among adolescents in Japan decreased but remained at high levels overall. There may not be a hazard-free threshold for smoking. Enhancing comprehensive tobacco control strategies is Japan's first step toward achieving smoke-free environments to protect youths. Implementation and verification of the effectiveness of smoke-free legislation should be considered.

Environmental Tobacco Smoke Exposure and Brain Functioning Associated with Smoking Cue-Reactivity and Inhibitory Control in Nonsmoking Adolescents

INTRODUCTION

Despite its well-established negative effects, environmental tobacco smoke (ETS) exposure remains highly prevalent worldwide. ETS exposure is associated with a wide range of physical and mental health-related problems among youth, including an increased likelihood to develop nicotine dependence. Up till now, neurocognitive effects of ETS exposure are largely unknown, while such effects could explain the role of ETS exposure in the development of nicotine dependence. Therefore, this preregistered study investigated the role of current ETS exposure in brain functioning associated with smoking cue-reactivity and inhibitory control.

METHOD

Concurrent with functional magnetic resonance imaging, nonsmoking adolescents aged 14-18 years (N = 51) performed a smoking cue-reactivity task, assessing brain functioning to smoking cues, and a Go/NoGo task measuring inhibitory control. ETS exposure was measured using a self-report questionnaire and biochemically verified.

RESULTS

No significant associations were observed between current ETS exposure and brain functioning associated with smoking cue-reactivity and inhibitory control.

CONCLUSION

These findings suggest that low-to-moderate levels of current ETS exposure are not associated with increased salience of smoking cues or deficits in inhibitory control in nonsmoking adolescents. Longitudinal research is needed to further clarify the exact effect of lifetime ETS exposure on brain functioning, as well as research focusing on the effects of higher levels of ETS exposure.

Does use of other tobacco products change when cigarette smoking status changes: A descriptive study of young adults

BACKGROUND

Whether polytobacco use or nicotine dependence (ND) change when cigarette smoking status changes in young adults is an understudied issue. Our objective was to describe use of other tobacco products (OTPs) and ND according to change in cigarette smoking status over four years in young adults.

METHODS

We drew data from a longitudinal study of 1294 adolescents age 12-13 at inception in 1999-2000 and followed into young adulthood. Among 790 participants with data at age 20 and 24, 22% had never smoked cigarettes; 37% were "sustained smokers"; 9% were "relapsers"; 10% had quit 1-3 years ago; and 22% had quit ≥4 years ago. We described past-year OTP (i.e., cigars/cigarillos, waterpipe, sundry tobacco products (i.e., pipe, bidis, chewing tobacco, snuff)) use and ND over 4 years in these groups.

RESULTS

At age 20, sustained smokers reported using a mean(SD) of 1.1(0.9) OTP in the past-year; relapsers reported 0.5(0.6); shorter-term quitters reported 0.9(0.7); longer-term quitters reported 0.3(0.6); and never smokers reported 0.2(0.4). There was no change in OTP use or ND in never smokers and longer-term quitters. Shorter-term quitters reduced the number of OTPs by -0.5(95% confidence interval: -0.7,-0.3) on average over 4 years; sustained smokers decreased by -0.2(-0.3,-0.1). Relapsers increased by 0.6(0.4,0.7) on average.

CONCLUSIONS

OTP use and ND were stable in early adulthood among never smokers, sustained smokers and longer-term quitters, but fluctuated in parallel with stopping and starting to smoke. Research is needed to ascertain the underpinnings of these fluctuations and whether they help or hinder cessation.

Effects of environmental tobacco smoke exposure on brain functioning in never-smoking adolescents

INTRODUCTION

Brain functioning, as indexed by event-related potentials (ERPs) representing smoking cue reactivity, inhibitory control, and reward processing, has been found to be compromised in smokers. However, whether environmental tobacco smoke (ETS) exposure in never smokers results in similar brain changes is unknown. This question is particularly relevant during adolescence, given ongoing brain maturation and a high risk of smoking initiation. The present study tested the associations between ETS exposure and ERPs reflecting cue reactivity (P3, LPP), inhibitory control (N2, P3), and reward processing (anticipation P3 (P3), feedback-related negativity (FRN)) among never-smoking adolescents.

METHODS

Eighty-four never-smoking adolescents (nonexposed = 32, exposed = 52) performed a smoking cue reactivity, a Go/NoGo, and a monetary incentive delay (MID) task while ERPs were measured.

RESULTS

Exposed and nonexposed groups did not differ in ERPs reflecting smoking cue reactivity, inhibitory control, and reward processing. A negative correlation between ETS exposure and the anticipatory P3 suggests reduced anticipatory reward sensitivity for nondrug rewards with increased levels of ETS exposure. However, since this effect was not consistent across analyses, no strong conclusions can be formulated. In the current study, few participants reported high levels of ETS exposure; therefore, further study is necessary.

CONCLUSIONS

Nevertheless, from this study, it can be concluded that low-to-moderate exposure to ETS during adolescence does not result in functional brain changes related to smoking cue reactivity, inhibitory control, and reward processing.

Type of e-liquid vaped, poly-nicotine use and nicotine dependence symptoms in young adult e-cigarette users: a descriptive study

BACKGROUND

Data are lacking on type of e-liquid vaped among e-cigarette users. Further, few studies assess all sources of nicotine used by e-cigarette users to assess whether poly-nicotine use relates to nicotine dependence (ND). The objectives were to describe young adult e-cigarette users by: (i) type of e-liquid vaped; (ii) poly-nicotine use; (iii) ND symptoms; and (iv) attempts to quit conventional cigarettes.

METHODS

Data were available in cycle 23 of a longitudinal investigation on the natural course of cigarette smoking and ND. A total of 775 young adults (44% male; mean (SD) age 30.5(1.0)) completed mailed self-report questionnaires in 2017-20.

RESULTS

Of 775 participants, 149 (19.2%) reported past-year e-cigarette use. Overall, 55.0% of e-cigarette users had used cannabis-containing e-liquid (31.5% vaped cannabis e-liquid exclusively); 50.4% used nicotine-containing e-liquid (23.5% vaped nicotine e-liquid exclusively); and 39.9% used e-liquid without nicotine (8.7% vaped e-liquid without nicotine exclusively). Most e-cigarette users (82.6%) used other nicotine-containing products including conventional cigarettes (72.5%); 60.8% reported ND symptoms, rising to 79.4% among those who vaped nicotine-containing e-liquid. Finally, 29.0% tried to quit conventional cigarettes using e-cigarettes in the past-year, but only 16.7% found them helpful.

CONCLUSIONS

E-cigarettes now appear to appeal to a broader market than smokers who want to quit. More than half of young adult e-cigarette users vaped cannabis-containing e-liquid in the past year while only one-quarter had used e-cigarettes to assist with cessation. Most e-cigarette users used multiple nicotine-containing substances (including combustible cigarettes) which were associated with reports of ND symptoms.

Targeting cognitive and emotional regulatory skills for smoking prevention in low-SES youth: A randomized trial of mindfulness and working memory interventions

Research to date provides striking evidence that youth from low socio-economic status (SES) households are at an increased risk for smoking. Converging evidence from developmental studies, psychopathology studies, intervention studies, and basic research on self-control abilities have identified working memory and distress tolerance as potential crucial modifiable risk factors to prevent smoking onset in this cohort. To confirm the value of these mechanistic targets, this randomized trial was designed to evaluate the influence of working memory and distress tolerance interventions on risk of smoking initiation. Recruiting primarily from low-income community afternoon programs, we randomized 93 adolescents to one of three intervention conditions, all of which were a prelude to a smoking-prevention informational intervention: (1) a working memory intervention, (2) a mindfulness training intervention to target distress tolerance, and (3) a wellness-focused control condition. Despite a number of adherence efforts, engagement in treatment was limited, and under these conditions no significant evidence was found either for differential efficacy for smoking prevention or for intervention effects on mechanistic targets. However, working memory capacity and distress tolerance were found to be negatively related to smoking propensity. As such, our mechanistic targets-working memory and distress tolerance--may well be processes undergirding smoking, despite the fact that our interventions did not adequately engage these targets.

Prevalence and characteristics of secondhand smoke and secondhand vapour exposure among youth

BACKGROUND

It is well established that secondhand smoke (SHS) is harmful, and concern about the potential dangers associated with secondhand vapour (SHV) (ie, vapour from electronic vapour products, EVP) is growing. The present study examines the prevalence and characteristics associated with SHS and SHV exposure.

METHODS

Data from youth aged 11-17 who completed the 2016 Florida Youth Tobacco Survey (n=58 616) were analysed. Demographics, past 30 day SHS and SHV exposure, environmental factors, cigarette and EVP use status, SHS and SHV harm perceptions, and tobacco susceptibility were assessed. Weighted multivariable logistic regressions were performed to examine characteristics associated with SHS and SHV exposure, and SHS and SHV exposure with tobacco susceptibility.

RESULTS

Overall, 42% of Florida youth reported SHS exposure and 29% reported SHV exposure during the past 30 days. Living in a home where tobacco use was permitted (vs not permitted) was positively associated with SHS (adjusted OR (AOR) 2.57) and SHV exposure (AOR 1.56). Perceived SHS as harmful (vs not harmful) was positively associated with SHS (AOR 1.73) and SHV exposure (AOR 1.97), while perceived SHV as harmful was negatively associated with SHS (AOR 0.86) and SHV exposure (AOR 0.56). SHS and SHV exposure was significantly associated with susceptibility to cigarette and EVP use (AOR 1.40 and 2.08, respectively).

CONCLUSIONS

Almost one-third of Florida youth reported SHV exposure. Factors associated with SHS and SHV exposure are somewhat similar, and exposure to SHS and SHV is associated with tobacco susceptibility in youth. Promoting tobacco-free homes is needed to protect youth from SHS and SHV exposure.

Rescuing cognitive and emotional regulatory skills to aid smoking prevention in at-risk youth: A randomized trial

Adolescence is a vulnerable period for smoking initiation, with disadvantaged teens particularly at risk. In addition, emotional and cognitive dysregulation is associated with an increased risk of smoking and makes it particularly challenging to benefit from standard substance use prevention interventions. The goal of the current study is to investigate the extent to which interventions designed to improve cognitive (working memory) and emotional (distress tolerance) regulatory processes enhance the effectiveness of a standard smoking prevention informational intervention. We will study adolescents (12-16 years of age) predominantly from racial/ethnic-minority and low-income households. Proximal smoking-risk outcome measures are used to allow testing of prevention models outside a full longitudinal study. We hope to generate new insights and approaches to smoking prevention among adolescents from lower socio-economic status (SES) by documenting the influence of working memory training and distress tolerance (mindfulness) interventions on cognitive/affective targets that place individuals at risk for smoking initiation and maintenance.

CLINICAL TRIALS REGISTRATION

NCT03148652.

Living with Smoker(s) and Smoking Cessation in Chinese Adult Smokers: Cross-Sectional and Prospective Evidence from Hong Kong Population Health Survey

Background: Results on the environmental influence on unassisted quitting are scarce. We investigated the associations of living with smoker(s) with quitting in Chinese adult smokers. Methods: We examined both cross-sectional and prospective data in the Hong Kong Population Health Survey recruited participants in 2003/04, and followed up to 2006. Unconditional logistic regression yielded adjusted odds ratios (AORs) of (i) planning to quit, (ii) ex-smoking (cross-sectional), and quitting (prospective) for living with smoker(s). 1679 ever smokers aged 18+ years at baseline, and 323 of them who were successfully followed-up were included in the cross-sectional, and prospective analysis. Results: At baseline, living with smoker(s) was significantly associated with lower odds of planning to quit in current smokers (AOR 0.41, 95% CI 0.25–0.68), and lower odds of ex-smoking (AOR 0.45, 95% CI 0.34–0.58), particularly if the smoker(s) smoked inside home (AOR 0.35, 95% CI 0.26–0.47). Prospectively, living with smoker(s) non-significantly predicted lower odds of new quitting (AOR 0.48, 95% CI 0.13–1.78). Conclusions: Our study has provided the first evidence in a Chinese general population that living with smoker(s) is an important barrier against smoking cessation. To boost quit rate in nonusers of smoking cessation services, smoking at home should be banned, especially for populations living in crowed urban environments that are typical of economically developed cities in China.

Airborne Nicotine, Secondhand Smoke, and Precursors to Adolescent Smoking

BACKGROUND AND OBJECTIVES

Secondhand smoke (SHS) directly increases exposure to airborne nicotine, tobacco's main psychoactive substance. When exposed to SHS, nonsmokers inhale 60% to 80% of airborne nicotine, absorb concentrations similar to those absorbed by smokers, and display high levels of nicotine biomarkers. Social modeling, or observing other smokers, is a well-established predictor of smoking during adolescence. Observing smokers also leads to increased pharmacological exposure to airborne nicotine via SHS. The objective of this study is to investigate whether greater exposure to airborne nicotine via SHS increases the risk for smoking initiation precursors among never-smoking adolescents.

METHODS

Secondary students (N = 406; never-smokers: n = 338, 53% girls, mean age = 12.9, SD = 0.4) participated in the AdoQuest II longitudinal cohort. They answered questionnaires about social exposure to smoking (parents, siblings, peers) and known smoking precursors (eg, expected benefits and/or costs, SHS aversion, smoking susceptibility, and nicotine dependence symptoms). Saliva and hair samples were collected to derive biomarkers of cotinine and nicotine. Adolescents wore a passive monitor for 1 week to measure airborne nicotine.

RESULTS

Higher airborne nicotine was significantly associated with greater expected benefits (R² = 0.024) and lower expected costs (R² = 0.014). Higher social exposure was significantly associated with more temptation to try smoking (R² = 0.025), lower aversion to SHS (R² = 0.038), and greater smoking susceptibility (R² = 0.071). Greater social exposure was significantly associated with more nicotine dependence symptoms; this relation worsened with higher nicotine exposure (cotinine R² = 0.096; airborne nicotine R² = 0.088).

CONCLUSIONS

Airborne nicotine exposure via SHS is a plausible risk factor for smoking initiation during adolescence. Public health implications include limiting airborne nicotine through smoking bans in homes and cars, in addition to stringent restrictions for e-cigarettes.

Predictors of Cigarette Smoking Initiation in Early, Middle, and Late Adolescence

PURPOSE

Little is known about age-related differences in risk factors for cigarette smoking initiation. We identified predictors of initiation in early, middle, and late adolescence from among sociodemographic factors, indicators of smoking in the social environment, psychological characteristics, lifestyle indicators, and perceived need for cigarettes.

METHODS

Data were drawn from a longitudinal study of 1,801 children recruited at age 10-11 years from 29 elementary schools in Montreal, Canada. Multivariable logistic regression within a generalized estimating equations framework was used to identify predictors among never smokers across three 2-year windows: age 11-13 years (n = 1,221); age 13-15 years (n = 737); and age 15-17 years (n = 690).

RESULTS

Among the 18 risk factors investigated, two differed across age. Friends' smoking, a strong risk factor in early adolescence (odds ratio [95% confidence interval] = 5.78 [3.90-8.58]), lost potency in late adolescence (1.83 [1.31-2.57]). Depressive symptoms, a risk factor in early and middle adolescence (1.60 [1.26-2.02] and 1.92 [1.45-2.54], respectively), were inversely associated in late adolescence (.76 [.58-1.00]). Sex, TV viewing, and weight-related goals were not associated with initiation at any age. All other factors were significant in two or three age groups.

CONCLUSIONS

Most risk factors for smoking initiation were stable across age. Tobacco control interventions may be robust for risk factors across age groups and may not need adjustment. At all ages, interventions should focus on eliminating smoking in the social environment and on reducing the availability of tobacco products.

Cardiovascular Consequences of Childhood Secondhand Tobacco Smoke Exposure: Prevailing Evidence, Burden, and Racial and Socioeconomic Disparities: A Scientific Statement From the American Heart Association

BACKGROUND

Although public health programs have led to a substantial decrease in the prevalence of tobacco smoking, the adverse health effects of tobacco smoke exposure are by no means a thing of the past. In the United States, 4 of 10 school-aged children and 1 of 3 adolescents are involuntarily exposed to secondhand tobacco smoke (SHS), with children of minority ethnic backgrounds and those living in low-socioeconomic-status households being disproportionately affected (68% and 43%, respectively). Children are particularly vulnerable, with little control over home and social environment, and lack the understanding, agency, and ability to avoid SHS exposure on their own volition; they also have physiological or behavioral characteristics that render them especially susceptible to effects of SHS. Side-stream smoke (the smoke emanating from the burning end of the cigarette), a major component of SHS, contains a higher concentration of some toxins than mainstream smoke (inhaled by the smoker directly), making SHS potentially as dangerous as or even more dangerous than direct smoking. Compelling animal and human evidence shows that SHS exposure during childhood is detrimental to arterial function and structure, resulting in premature atherosclerosis and its cardiovascular consequences. Childhood SHS exposure is also related to impaired cardiac autonomic function and changes in heart rate variability. In addition, childhood SHS exposure is associated with clustering of cardiometabolic risk factors such as obesity, dyslipidemia, and insulin resistance. Individualized interventions to reduce childhood exposure to SHS are shown to be at least modestly effective, as are broader-based policy initiatives such as community smoking bans and increased taxation.

PURPOSE

The purpose of this statement is to summarize the available evidence on the cardiovascular health consequences of childhood SHS exposure; this will support ongoing efforts to further reduce and eliminate SHS exposure in this vulnerable population. This statement reviews relevant data from epidemiological studies, laboratory-based experiments, and controlled behavioral trials concerning SHS and cardiovascular disease risk in children. Information on the effects of SHS exposure on the cardiovascular system in animal and pediatric studies, including vascular disruption and platelet activation, oxidation and inflammation, endothelial dysfunction, increased vascular stiffness, changes in vascular structure, and autonomic dysfunction, is examined.

CONCLUSIONS

The epidemiological, observational, and experimental evidence accumulated to date demonstrates the detrimental cardiovascular consequences of SHS exposure in children.

IMPLICATIONS

Increased awareness of the adverse, lifetime cardiovascular consequences of childhood SHS may facilitate the development of innovative individual, family-centered, and community health interventions to reduce and ideally eliminate SHS exposure in the vulnerable pediatric population. This evidence calls for a robust public health policy that embraces zero tolerance of childhood SHS exposure.

Secondhand smoke exposure and susceptibility to initiating cigarette smoking among never-smoking students in selected African countries: Findings from the Global Youth Tobacco Survey

BACKGROUND

Exposure to secondhand smoke (SHS) causes premature death and illness in non-smokers. We examined SHS exposure at home and in public places, as well as susceptibility to initiate cigarette smoking among never cigarette smokers. We used 2006-2011 Global Youth Tobacco Survey (GYTS) data from 29 African countries (56,967 students).

METHODS

GYTS is a nationally representative, self-administered school-based survey, conducted among students aged 13-15years. Prevalence ratio, estimates and 95% confidence intervals were computed for SHS exposure in the homes and public places separately. The two-sample t-test was used to assess the difference in susceptibility to smoking by SHS exposure among never-smoking students (α=0.05).

RESULTS

Among never-smoking students, exposure to SHS at home ranged from 12.7% (Cape Verde) to 44.0% (Senegal). The prevalence ratio (PR) comparing susceptibility to smoking initiation among never smokers exposed to SHS at home to those who were not exposed at home ranged from 1.2 to 2.6. Exposure to SHS in public places ranged from 23.9% (Cape Verde) to 80.4% (Mali). Of the countries being studied, 8 countries showed a significant difference in susceptibility to smoking initiation among never smokers exposed to SHS in public places compared to those not exposed in public places. (PR ranged from 0.5-3.5).

CONCLUSION

In many African countries in the study, a substantial proportion of students who never smoked are exposed to SHS at home and in public places. Majority of never smokers who were exposed to SHS at home and in public places had a higher prevalence of susceptibility to initiate smoking than those that were not exposed to SHS at home and in public places. Adoption and enforcement of smoke-free policies in public places and smoke-free rules at home could substantially contribute to reducing SHS exposure in many of these countries.

Negative urgency and emotion regulation predict positive smoking expectancies in non-smoking youth

INTRODUCTION

The purpose of the study was to better understand early risk for positive smoking expectancies, which have been shown to be consistent predictors of smoking initiation among youth. Two affect-based risk factors-negative urgency and emotion dysregulation-associated with smoking behaviors among youth, were examined for unique and interactive effects on positive smoking expectancies among substance-naïve youth.

METHODS

Participants were 61 10-14-year-old children with virtually no drug use (less than 5 substance use incidents across the lifetime), who were drawn from the community.

RESULTS

Both negative urgency and emotion dysregulation were significantly associated with positive social facilitation smoking expectancies. Further, negative urgency was significantly related to positive social facilitation smoking expectancies at higher levels of emotion dysregulation (b=.09, p=.001).

CONCLUSION

The findings provide evidence that both emotion dysregulation and negative urgency are positively associated with positive social-related smoking expectancies among a sample of 10-14-year-olds. Children who are emotionally dysregulated and who act rashly in response to negative emotions appear more likely to endorse beliefs regarding the socially enhancing effects of smoking, suggesting that these youth may be at high risk for smoking initiation.

Secondhand tobacco smoke exposure and susceptibility to smoking, perceived addiction, and psychobehavioral symptoms among college students

OBJECTIVE

To examine the association of secondhand smoke (SHS) exposure with susceptibility to smoking, perceived addiction, and psychobehavioral effects of exposure among never- and ever-smoking college students.

PARTICIPANTS

Participants were 665 college students at a large, southeastern university in the United States.

METHODS

This study is a secondary analysis of online cross-sectional survey data from randomly selected students in April 2013.

RESULTS

Thirty-eight percent of the sample had moderate to high SHS exposure. Among never-smokers, SHS exposure was associated with increased susceptibility to initiating smoking. Among ever-smokers, SHS exposure was not associated with their perceived addiction to tobacco. In the total sample, SHS exposure was associated with greater psychobehavioral symptoms of exposure.

CONCLUSIONS

SHS exposure may the increase risk of smoking, especially among never-smoking college students. This study strengthens the need for prevention strategies that limit SHS exposure in college environments.

Parental smoke exposure and the development of nicotine craving in adolescent novice smokers: the roles of DRD2, DRD4, and OPRM1 genotypes

BACKGROUND

Among adolescent novice smokers, craving is often the first, and is the most reported, symptom of nicotine dependence. Until now, little has been known about the development of craving symptoms in novice smokers. The aim of this study was to identify specific genetic (i.e., DRD2 Taq1A, DRD4 48 bp VNTR, and OPRM1 A118G polymorphisms) and environmental mechanisms that underlie the emergence of both cue-induced and cognitive craving among adolescent novice smokers.

METHOD

A five-wave longitudinal, genetically-informed survey study was conducted with intervals of four months. The sample included 376 early adolescent smokers (12-13 years of age at baseline). Self-report questionnaires were completed regarding smoking behavior, observed parental smoking behavior, and both cue-induced and cognitive craving.

RESULTS

Data were analyzed with a latent growth curve approach. For both cue-induced and cognitive craving, significant interaction effects were found for DRD2 Taq1A with parental smoke exposure. A1-allele carriers did not seem to be influenced by the environment with regard to craving development. Adolescents who are homozygous for the A2-allele and who are more exposed to parental smoking experience the highest levels of both types of craving over time. No significant interaction effects were found between parental smoke exposure and DRD4 48 bp VNTR or OPRM1 A118G.

CONCLUSIONS

Previous studies identified DRD2 Taq1A A1-allele carriers as vulnerable to developing nicotine dependence. However, this study showed that parental smoking increased the chances of developing dependence more rapidly for early adolescents who are considered to be less sensitive to the rewarding effects of nicotine according to their DRD2 Taq1A genotype. It is thus especially important that these young people not be exposed to smoking in their social environment.

Secondhand smoke exposure and other correlates of susceptibility to smoking: a propensity score matching approach

Secondhand smoke (SHS) exposure is responsible for numerous diseases of the lungs and other bodily systems among children. In addition to the adverse health effects of SHS exposure, studies show that children exposed to SHS are more likely to smoke in adolescence. Susceptibility to smoking is a measure used to identify adolescent never-smokers who are at risk for smoking. Limited research has been conducted on the influence of SHS on susceptibility to smoking. The purpose of this study was to determine a robust measure of the strength of correlation between SHS exposure and susceptibility to smoking among never-smoking U.S. adolescents. This study used data from the 2009 National Youth Tobacco Survey to identify predictors of susceptibility to smoking in the full (pre-match) sample of adolescents and a smaller (post-match) sample created by propensity score matching. Results showed a significant association between SHS exposure and susceptibility to smoking among never-smoking adolescents in the pre-match (OR=1.47) and post-match (OR=1.52) samples. The odds ratio increase after matching suggests that the strength of the relationship was underestimated in the pre-match sample. Other significant correlates of susceptibility to smoking identified include: gender, race/ethnicity, personal income, smoke-free home rules, number of smoking friends, perception of SHS harm, perceived benefits of smoking, and exposure to pro-tobacco media messages. The use of propensity score matching procedures reduced bias in the post-match sample, and provided a more robust estimate of the influence of SHS exposure on susceptibility to smoking, compared to the pre-match sample estimates.

A systematic review of secondhand tobacco smoke exposure and smoking behaviors: Smoking status, susceptibility, initiation, dependence, and cessation

OBJECTIVES

To examine the association between secondhand tobacco smoke exposure (SHSe) and smoking behaviors (smoking status, susceptibility, initiation, dependence, and cessation).

METHODS

Terms and keywords relevant to smoking behaviors and secondhand tobacco smoke exposure were used in a search of the PubMed database. Searches were limited to English language peer-reviewed studies up till December 2013. Included papers: a) had clearly defined measures of SHSe and b) had clearly defined measures of outcome variables of interest. A total of 119 studies were initially retrieved and reviewed. After further review of references from the retrieved studies, 35 studies were finally selected that met all eligibility criteria.

RESULTS

The reviewed studies consisted of thirty-five (89.7%) studies with differing measures of SHSe (including questionnaire and biological measures) and varying definitions of main outcome variables of interest between studies. The majority of the studies (77%) were cross-sectional in nature. The majority of studies found that SHSe was associated with greater likelihood of being a smoker, increased susceptibility and initiation of smoking, greater nicotine dependence among nonsmokers, and poorer smoking cessation.

CONCLUSIONS

The review found positive associations between SHSe and smoking status, susceptibility, initiation and nicotine dependence and a negative association with smoking cessation. In light of design limitations, future prospective and clinical studies are needed to better understand the mechanisms whereby SHSe influences smoking behaviors.

Behavioral and Physiological Responses to Nicotine Patch Administration Among Nonsmokers Based on Acute and Chronic Secondhand Tobacco Smoke Exposure

INTRODUCTION

Despite the large amount that is known about the physical health effects of secondhand tobacco smoke (SHS) exposure, little is known about the behavioral health effects. Nicotine, the principle psychoactive substance in SHS, elicits subjective mood and physiological responses in nonsmokers. However, no studies have examined the subjective mood or physiological responses to nicotine in nonsmokers while accounting for prior chronic or acute SHS exposure.

METHODS

A 7-mg nicotine patch was administered to 17 adult nonsmokers for 2 hr. Main outcome measures obtained at ½ hr, 1 hr, and 2 hr were subjective behavioral drug effects (based on eleven 10-cm Visual Analog Scales [VASs]) and the physiological measures of heart rate, blood pressure, and serum nicotine levels. Analysis of outcome data was based on participants' chronic (using hair nicotine) or acute (using saliva cotinine) SHS exposure.

RESULTS

Greater chronic SHS exposure was negatively associated with pleasurable responses to nicotine administration ("drug feels good" score at 2-hr time point, Spearman's ρ = -.65, p < .004), whereas greater acute SHS exposure was associated with positive responses ("like feeling of drug" score at 2-hr time point, Spearman's ρ = .63, p < .01). There were no associations between chronic or acute exposure and physiological changes in response to nicotine administration.

DISCUSSION

The findings of this study may be useful in providing preliminary empirical data for future explorations of the mechanism whereby SHS exposure can influence behavioral outcomes in nonsmokers. Such studies can inform future interventions to reduce the physical and behavioral health risks associated with SHS exposure.

Development and psychometric properties of the Social Smoking Situations (S(3)) Scale: an enhanced measure of social exposure to smoking during adolescence

Common questions of exposure to smoking, such as number of parents, siblings, or friends who smoke, fail to capture the contexts in which the exposure occurs. This study developed the Social Smoking Situations (S(3)) Scale to more precisely measure contextual exposure to smoking during adolescence. Informed by the cue-reactivity literature and using informal focus groups, items of contextual exposure to smoking were generated for three categories of smokers: parents, siblings, and peers. Participants (N=761; Mage=15.6, SD=1.3; 61.4% female) were recruited as part of the AdoQuest Study in Montreal, QC. Principal components analysis was used to identify the component structure of the parent, sibling, and peer versions of the S(3) Scale. S(3) scores were computed subsequently to test their association with smoking behavior and smoking expectancies. Further, S(3) scores were compared with common questions (i.e., number of smokers) via univariate modeling to determine which would generate larger estimates of effect size when predicting smoking behavior and smoking expectancies. Overall, S(3) scores generated larger estimates than common questions; this finding was consistent across the parent (ORavg: 2.59 vs. 1.36), sibling (ORavg: 3.44 vs. 1.59), and peer (ORavg: 3.89 vs. 1.38) versions. The S(3) Scale is a new psychometrically sound instrument that may provide a more robust measurement of social exposure to smoking during adolescence. Importantly, it has the potential to strengthen prevention programming and intervention efforts aimed at adolescents, as it could depict a more precise portrait of the individual and contextual sources of social exposure to smoking.

Initial responses to the first dose of nicotine in novel smokers: the role of exposure to environmental smoking and genetic predisposition

BACKGROUND

Sensitivity to initial smoking constitutes an early predictor of the risk of dependence. We investigated the role of exposure to smoking (by parents, siblings, and peers) and reward-related candidate gene polymorphisms (OPRM1 A118G, DRD2 TaqlA and DRD4 bp VNTR) in adolescents' responses to initial smoking.

METHODS

We used cross-sectional survey data and saliva samples from 171 Dutch students who had never inhaled on a cigarette (mean age: 13.9 years). The outcome measure was adolescents' self-reported responses to initial smoking.

RESULTS

Exposure to peer smoking was associated with increased liking (OR = 1.74, CI = 1.13-2.70) and more pleasant sensations (β = .21, p = .01). Exposure to maternal smoking was associated with less unpleasant sensations (β = -.20, p = .01). Adolescents carrying the G-variant of the OPRM1 A118G polymorphism were more likely to report liking (OR = 2.50, CI = 1.09-5.73) and adolescents homozygous for the C-variant of the DRD2 TaqlA polymorphism reported less unpleasant sensations (β = .18, p = .04).

CONCLUSION

Although preliminary, these findings suggest that exposure to environmental smoking and polymorphisms in the OPRM1 and DRD2 gene may affect initial sensitivity to nicotine, an early phenotype of the risk of dependence. In the future, collaborative efforts to combine data from multiple studies in meta-analyses are needed to improve accuracy of estimated effects in genetic studies.

Predictors of nicotine dependence symptoms among never-smoking adolescents: a longitudinal analysis from the Nicotine Dependence in Teens Study

BACKGROUND

Recent cross-sectional studies suggest some adolescents who have never smoked cigarettes experience nicotine dependence (ND) symptoms and that exposure to second-hand smoke, social exposure to smoking, and alcohol use are plausible correlates. The aim of this study was to replicate and extend these findings by investigating possible predictors of ND symptoms longitudinally.

METHOD

Participants included 847 secondary school students who had never smoked cigarettes enrolled in the Nicotine Dependence in Teens Study. Adolescents completed self-report questionnaires measuring smoking status, ND symptoms, and risk factors for ND in smokers (i.e., socio-demographic indicators, social exposure to smoking, psychosocial indicators, and substance use) in 20 survey cycles from 7 to 11th grade. Generalized estimating equations, which account for repeated measures within individuals, were used to test the predictors of ND symptoms.

RESULTS

Consistent with previous research, 7.8% of never-smokers across all cycles endorsed at least one ND symptom. Younger age (p ≤ .001), country of birth (p ≤ .05), peer smoking (p ≤ .001), teacher smoking (p ≤ .05), depression (p ≤ .05), stress (p ≤ .001), lower self-esteem (p ≤ .05), impulsivity (p ≤ .05), and alcohol use (p ≤ .001) predicted greater ND symptoms in multivariable modeling.

CONCLUSIONS

Replicating previous cross-sectional findings, peer smoking and alcohol use predicted ND symptoms among never-smoking adolescents. Extending these findings, previous predictors only observed among ever-smokers, including socio-demographic and psychosocial indicators, also predicted ND symptoms. This longitudinal investigation demonstrated the temporal relation of the predictors preceding ND symptoms. Future research should consider longer prospective studies with younger children to capture early onset of ND symptoms and with longer follow-up to detect eventual smoking uptake.

Responses to environmental smoking in never-smoking children: can symptoms of nicotine addiction develop in response to environmental tobacco smoke exposure?

A recent line of studies has brought attention to the question whether repeated exposure to environmental tobacco smoke (ETS) is capable of producing psycho-physiological effects in non-smokers and whether symptoms of nicotine dependence can develop in the absence of active smoking. Children seem to be particularly vulnerable to the effects of ETS. We examined the occurrence of psycho-behavioural symptoms, designed to assess nicotine addiction and nicotine withdrawal, in a sample of 778 never-smoking children aged 9-12 years using cross-sectional survey data collected in 15 Dutch primary schools. In the present study, 6% of never-smoking children reported symptoms of craving, 8% reported cue-triggered wanting to smoke, and 20% reported subjective symptoms in response to ETS exposure. In never-smoking children, a higher number of smokers in the child's social environment was associated with more symptoms of cue-triggered wanting to smoke and more subjective symptoms in response to ETS. Never-smoking children and children who had initiated smoking were equally likely to report subjective symptoms in response to ETS exposure. In conclusion, environmental smoking is associated with self-reported psycho-behavioural symptoms in never-smoking children. Future research needs to investigate whether symptoms in children exposed to ETS are physiologically based or whether they reflect other characteristics which predispose youth for smoking initiation in the future.

Attention-deficit/hyperactivity disorder subtype differentially predicts smoking expectancies in adolescents

PURPOSE

Attention deficit hyperactivity disorder (ADHD) is an established risk factor for smoking; however, no studies have considered whether precursors to smoking behavior differ among adolescents with ADHD. Smoking expectancies are beliefs about the potential consequences of smoking, and they develop before smoking initiation. ADHD characteristics may contribute to the formation of expectancies and eventual smoking behavior. We evaluated whether clinical levels of ADHD subtypes differentially predicted smoking expectancies.

METHODS

Adolescents (n = 221; age mean = 12.67 years) completed the Smoking Expectancy Scale for Adolescents, answered standardized questions about their smoking behavior, and provided expired breath samples to verify never-smoking status. Parents completed the Conners' Parent Rating Scale for ADHD symptoms of inattention and hyperactivity/impulsivity.

RESULTS

Adolescents with clinical levels of inattention were significantly less likely to endorse negative consequences, including Expected Costs (odds ratio [OR] = .16), Appearance-Presentation Costs (OR = .29), Social Costs (OR = .19), Health Costs (OR = .21), and Addiction Costs (OR = .39). Inattentive female adolescents were significantly more likely to endorse Weight Control as a consequence. Adolescents with clinical levels of hyperactivity/impulsivity were more likely to endorse positive consequences, including Expected Benefits (OR = 5.31), Affect Control (OR = 2.60), and Boredom Reduction (OR = 3.14); they were less likely to endorse Social Costs (OR = .27).

CONCLUSIONS

ADHD subtype differentially predicted smoking expectancies. Adolescents with ADHD may be more vulnerable to developing pro-smoking expectancies due to subtype-related deficits in neurocognitive processing. These findings have potential implications for developing targeted smoking prevention programs.

Smoking family, secondhand smoke exposure at home, and nicotine addiction among adolescent smokers

INTRODUCTION

Smoking family predicts adolescent smoking, but whether the level of nicotine addiction is affected by exposure to secondhand smoke (SHS) is unclear. We investigated the associations of smoking family and SHS exposure at home with morning smoking and heavier smoking among Chinese adolescent smokers.

METHODS

In a school-based anonymous survey, 2182 adolescent smokers reported their smoking behaviors, smoking status of family members and peers, and SHS exposure at home and outside home in the past 7 days. Families with one or more smoking members (excluding the subject) were classified as smoking families and otherwise as non-smoking families. Smoking or wanting to smoke first thing in the morning (morning smoking), and consuming more cigarettes (heavier smoking) denoted higher levels of nicotine addiction. Regression analysis yielded adjusted odds ratios (AORs) for morning smoking and β-coefficients for heavier smoking adjusting for potential confounders.

RESULTS

Living with siblings and other co-residing family members who smoked was significantly associated with morning smoking and heavier smoking. Compared with non-smoking families without SHS exposure at home, the AORs (95% CI) for morning smoking were 0.99 (0.76 to 1.29) for 0 day/week, 1.19 (0.95 to 1.50) for 1-3 days/week, 1.76 (1.41 to 2.21) for 4-7 days/week (p for trend <0.001) and 1.50 (1.23 to 1.83) for any days/week of SHS exposure at home in smoking families. Similarly, 4-6 days/week of SHS exposure at home significantly predicted heavier smoking.

CONCLUSION

Living with smoking family members and SHS exposure at home are associated with nicotine addiction in Chinese adolescent smokers.

Smoking family, secondhand smoke exposure at home, and quitting in adolescent smokers

INTRODUCTION

This study investigated the associations of smoking family and secondhand smoke (SHS) exposure at home with quit attempts and smoking cessation among adolescents.

METHODS

Students from 85 randomly selected secondary schools in Hong Kong were surveyed using an anonymous self-administered questionnaire on SHS exposure at home and outside the home in the past 7 days, quit attempts, smoking cessation, sociodemographic characteristics, and smoking status of family members and peers. Families with 1 or more smoking members (excluding the subject) were classified as smoking families and otherwise as nonsmoking families. Logistic regression yielded adjusted odds ratios (AORs) for quit attempts and smoking cessation in smoking families with or without SHS exposure at home compared with nonsmoking families.

RESULTS

Of 4,361 students who had smoked in the past 12 months, 70.3% were living with smokers and 52.8% were exposed to SHS at home. Compared with nonsmoking families, the AORs (95% CI) for making at least 1 quit attempt in the past 12 months were 0.80 (0.61-1.05) for 0 day, 0.80 (0.63-1.04) for 1-3 days, and 0.65 (0.50-0.86) for 4-7 days of SHS exposure at home. The corresponding AORs (95% CI) for smoking cessation were 0.58 (0.48-0.70), 0.45 (0.35-0.58), and 0.49 (0.41-0.60) (p for trend <.001). Any SHS exposure at home was associated with 28% and 53% lower odds of quit attempts and smoking cessation, respectively.

CONCLUSIONS

Living with smoker(s) and especially being exposed to SHS at home may hinder quit attempts and smoking cessation among Chinese adolescent smokers.