Determinants of progression of nicotine dependence symptoms in adolescent waterpipe smokers.

INTRODUCTION: Waterpipe smoking continues to pose significant challenges to tobacco control efforts and many adolescent waterpipe smokers experience symptoms of nicotine dependence (ND). This study examined the predictors of progression of ND symptoms in adolescent waterpipe smokers. METHODS: We assembled a cohort of Lebanese adolescents enrolled in eighth and ninth grades at baseline, and surveyed them every 6 months over the next 24 months. Progression of ND symptoms was defined as an increase over time in the number of items endorsed on the Hooked on Nicotine Checklist. Predictors included individual (eg, psychological factors, attitudes towards waterpipe, school performance, physical activity) and socioenvironmental (eg, smoking among parents, siblings and close friends; the café environment) attributes. RESULTS: Among 264 adolescent waterpipe smokers (baseline mean age=14.6 years, 50.4% females), 105 (39.7%) progressed on ND symptoms during follow-up. Predictors of progression were higher baseline stress (OR 1.11, 95% CI 1.03 to 1.19) and higher self-esteem (OR 1.14, 95% CI 1.05 to 1.24). Reporting difficulty refraining from smoking waterpipe while in a restaurant was the strongest predictor of progression (OR 4.04, 95% CI 1.44 to 11.34). Having a mother with ≥12 years of education protected against progression of ND (OR 0.46, 95% CI 0.21 to 0.99). CONCLUSIONS: A significant proportion of adolescent waterpipe smokers progressed on ND. Venue-based policies such as limiting youth access to waterpipe cafés are warranted.

Evidence of Altered Brain Responses to Nicotine in an Animal Model of Attention Deficit/Hyperactivity Disorder.

INTRODUCTION: Individuals with attention deficit/hyperactivity disorder (ADHD) are susceptible to earlier and more severe nicotine addiction. To shed light on the relationship between nicotine and ADHD, we examined nicotine's effects on functional brain networks in an animal model of ADHD. METHODS: Awake magnetic resonance imaging was used to compare functional connectivity in adolescent (post-natal day 44 ± 2) males of the spontaneously hypertensive rat (SHR) strain and two control strains, Wistar-Kyoto and Sprague-Dawley (n = 16 each). We analyzed functional connectivity immediately before and after nicotine exposure (0.4 mg/kg base) in naïve animals, using a region-of-interest approach focussing on 16 regions previously implicated in reward and addiction. RESULTS: Relative to the control groups, the SHR strain demonstrated increased functional connectivity between the ventral tegmental area (VTA) and retrosplenial cortex in response to nicotine, suggesting an aberrant response to nicotine. In contrast, increased VTA-substantia nigra connectivity in response to a saline injection in the SHR was absent following a nicotine injection, suggesting that nicotine normalized function in this circuit. CONCLUSIONS: In the SHR, nicotine triggered an atypical response in one VTA circuit while normalizing activity in another. The VTA has been widely implicated in drug reward. Our data suggest that increased susceptibility to nicotine addiction in individuals with ADHD may involve altered responses to nicotine involving VTA circuits. IMPLICATIONS: Nicotine addiction is more common among individuals with ADHD. We found that two circuits involving the VTA responded differently to nicotine in animals that model ADHD in comparison to two control strains. In one circuit, nicotine normalized activity that was abnormal in the ADHD animals, while in the other circuit nicotine caused an atypical brain response in the ADHD animals. The VTA has been implicated in drug reward. Our results would be consistent with an interpretation that nicotine may normalize abnormal brain activity in ADHD, and that nicotine may be more rewarding for individuals with ADHD.

Smoking Cessation in Adolescents: targeted approaches that work.

Smoking Cessation in adolescents can be considered in a developmental context to enable the clinician to individualise the appropriate assessment and management of the young person they are seeing whether it is in a primary or tertiary care setting. Adolescence is a time of rapid neurocognitive and hormonal change with these factors affected by personality and behavioural factors as well as family, cultural and psychosocial context. Adolescents are uniquely vulnerable to smoking initiation and nicotine addiction throughout these years. Increased awareness of the risks of smoking and using opportunities to assess and intervene regarding smoking cessation are integral to clinical practice for all clinicians seeing young people. This review will discuss the demographics of adolescent smoking, risk factors, assessing smoking and nicotine addiction, the importance of brief interventions, the evidence base for appropriate interventions, particularly in high risk groups and will emphasise innovative training for health professionals in adolescent smoking cessation.

Early symptoms of nicotine dependence among adolescent waterpipe smokers.

BACKGROUND: Although waterpipe smoking is increasingly popular among youth and can lead to nicotine dependence (ND), no studies have documented how ND develops in waterpipe smokers. We examined the emerging symptoms of ND among adolescent waterpipe smokers in Lebanon. METHODS: Individual confidential interviews were used to evaluate ND in 160 waterpipe smokers and 24 cigarette smokers from a sample of 498 students enrolled in 8th and 9th grades in Lebanon. RESULTS: Among waterpipe smokers, 71.3% endorsed at least one Hooked on Nicotine Checklist (HONC) symptom and 38.1% developed the full syndrome of ND (≥3 criteria using the International Classification of Diseases, 10th revision). The early symptoms of ND among waterpipe smokers were craving (25%), feeling addicted (22.5%), and failed quit attempts (14.3%). Among those who reached the respective milestones, median tobacco use when the first HONC symptom emerged was 7.5 waterpipes/month with smoking frequency of 6 days/month; the median tobacco use for the full syndrome of ND was 15 waterpipes/month with smoking frequency of 15 days/month. Among those who had already reached these milestones, the first HONC symptom appeared 10.9 months after the initiation of waterpipe smoking, and the full syndrome of ND was reached at 13.9 months. In addition, cues such as seeing or smelling waterpipe, and the café environment triggered craving in most waterpipe smokers with symptoms of ND. CONCLUSIONS: Symptoms of ND develop among adolescent waterpipe smokers at low levels of consumption and frequency of use. Craving for nicotine triggered by waterpipe-specific cues is reported even at this young age. Waterpipe-specific ND prevention and intervention programmes for youth are needed.

Can tobacco dependence provide insights into other drug addictions?

Within the field of addiction research, individuals tend to operate within silos of knowledge focused on specific drug classes. The discovery that tobacco dependence develops in a progression of stages and that the latency to the onset of withdrawal symptoms after the last use of tobacco changes over time have provided insights into how tobacco dependence develops that might be applied to the study of other drugs.As physical dependence on tobacco develops, it progresses through previously unrecognized clinical stages of wanting, craving and needing. The latency to withdrawal is a measure of the asymptomatic phase of withdrawal, extending from the last use of tobacco to the emergence of withdrawal symptoms. Symptomatic withdrawal is characterized by a wanting phase, a craving phase, and a needing phase. The intensity of the desire to smoke that is triggered by withdrawal correlates with brain activity in addiction circuits. With repeated tobacco use, the latency to withdrawal shrinks from as long as several weeks to as short as several minutes. The shortening of the asymptomatic phase of withdrawal drives an escalation of smoking, first in terms of the number of smoking days/month until daily smoking commences, then in terms of cigarettes smoked/day.The discoveries of the stages of physical dependence and the latency to withdrawal raises the question, does physical dependence develop in stages with other drugs? Is the latency to withdrawal for other substances measured in weeks at the onset of dependence? Does it shorten over time? The research methods that uncovered how tobacco dependence emerges might be fruitfully applied to the investigation of other addictions.

Nicotine and Resting-State Functional Connectivity: Effects of Intermittent Doses.

INTRODUCTION: It is unknown how the timing between doses might affect nicotine's impact on neural activity. Our objective was to examine how the interdose interval affects nicotine's impact on resting-state functional connectivity (rsFC). MATERIALS AND METHODS: Adult male Sprague-Dawley rats were administered nicotine daily (0.4 mg/kg) over 6 days while control animals received saline vehicle. Functional magnetic resonance imaging was used to measure rsFC before and after a challenge dose of nicotine (0.4 mg/kg) delivered for the first time and 3, 6, 12, or 24hr after the previous dose. RESULTS: As the interval between nicotine doses increased from 3 to 24hr, the strength of rsFC increased in some circuits, particularly the nucleus accumbens and prefrontal circuits, and decreased in others, namely the interpeduncular nucleus, hippocampus, caudoputamen, retrosplenial cortex, ventral tegmental, and the insular circuits. CONCLUSIONS: These data indicate that the effect that nicotine has on the brain is affected by the amount of time that has passed since the previous dose. The effect on rsFC of cumulative doses is not additive. This may have important implications for the study of nicotine addiction as it implies that the same dose of nicotine might have a different impact on the brain depending on the time elapsed from the previous exposure.

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.

Retail impact of raising tobacco sales age to 21 years.

The majority of tobacco use emerges in individuals before they reach 21 years of age, and many adult distributors of tobacco to youths are young adults aged between 18 and 20 years. Raising the tobacco sales minimum age to 21 years across the United States would decrease tobacco retailer and industry sales by approximately 2% but could contribute to a substantial reduction in the prevalence of youths' tobacco use and dependency by limiting access.

Which interventions against the sale of tobacco to minors can be expected to reduce smoking?

OBJECTIVE: Signatories of the Framework Convention on Tobacco Control have committed themselves to prohibiting the sale of tobacco to minors. The tobacco industry has a long history of legal challenges to such restrictions claiming that they cannot be expected to reduce youth smoking. The object of this study was to determine if disrupting the sale of tobacco to minors can be expected to reduce tobacco use by youths. METHODS: A comprehensive literature search was conducted for studies that evaluated the impact on youth tobacco use of efforts to disrupt the sale of tobacco to youths. RESULTS: There was little evidence that merely enacting a law without sufficient enforcement had any impact on youth tobacco use. There was no evidence that merchant education programmes had any impact on youth older than 12 years of age. There was no evidence that enforcement efforts that failed to reduce the sale of tobacco to minors had any beneficial impact. All enforcement programmes that disrupted the sale of tobacco to minors reduced smoking among youth. CONCLUSIONS: Government officials can expect that enforcement programmes that disrupt the sale of tobacco to minors will reduce adolescent smoking.

The assessment of tobacco dependence in young users of smokeless tobacco.

INTRODUCTION: As all published measures of dependence for users of smokeless tobacco (dippers) have poor reliability, in the present work the Hooked on Nicotine Checklist (HONC) and the Autonomy Over Smoking Scale (AUTOS) were evaluated for use with this population. Dippers and smokers were also compared in relation to dependence, the pleasure derived from using tobacco and the latency to the onset of withdrawal. METHODS: In 2010, an anonymous self-completed paper survey was administered to 1541 students of mixed race and ethnicity in grades 9-12 (mean age 15.9 years) in a Florida high school where students used cigarettes and smokeless tobacco. RESULTS: The reliability (Cronbach's α) for the HONC was 0.90 for smokers (n = 139) and 0.91 for dippers (n = 85), and for the AUTOS was 0.94 for smokers and dippers. Dippers and smokers did not differ significantly in relation to scores on the HONC, AUTOS, latency to withdrawal onset or pleasure derived from smoking. One or more symptoms on the HONC were reported by 56% of dippers and 57% of smokers with <100 lifetime uses of their favoured tobacco product, and by 91% of dippers and 91% of smokers with ≥ 100 lifetime uses (not significant). Greater lifetime use was associated with a significantly shorter latency to withdrawal for smokers and dippers. CONCLUSIONS: The HONC and AUTOS are highly reliable measures of dependence for adolescent users of cigarettes and smokeless tobacco. Using these measures and other indicators, no meaningful differences in dependence were found between dippers and smokers at comparable levels of lifetime use.

Health effects of the Federal Bureau of Prisons tobacco ban.

BACKGROUND: Tobacco smoking remains the leading cause of preventable death in America, claiming 450,000 lives annually. Chronic Obstructive Pulmonary Disease, caused by smoking in the vast majority of cases, became the third leading cause of death in the U.S. in 2008. The burden of asthma, often exacerbated by tobacco exposure, has widespread clinical and public health impact. Despite this considerable harm, we know relatively little about the natural history of lung disease and respiratory impairment in adults, especially after smoking cessation. METHODS/DESIGN: Our paper describes the design and rationale for using the 2004 Federal Bureau of Prisons tobacco ban to obtain insights into the natural history of respiratory diseases in adult men and women of different races/ethnicities who are imprisoned in federal medical facilities. We have developed a longitudinal study of new prison arrivals, with data to be collected from each participant over the course of several years, through the use of standardized questionnaires, medical chart reviews, lung function tests, six-minute walk tests, and stored serum for the analysis of present and future biomarkers. Our endpoints include illness exacerbations, medication and health services utilization, lung function, serum biomarkers, and participants' experience with their health and nicotine addiction. DISCUSSION: We believe the proposed longitudinal study will make a substantial contribution to the understanding and treatment of respiratory disease and tobacco addiction.

Systematic literature review assessing tobacco smoke exposure as a risk factor for serious respiratory syncytial virus disease among infants and young children.

BACKGROUND: The role of environmental tobacco smoke (ETS) exposure as a risk factor for serious respiratory syncytial virus (RSV) disease among infants and young children has not been clearly established. This systematic review was conducted to explore the association between ETS exposure and serious RSV disease in children younger than 5 years, including infants and young children with elevated risk for serious RSV disease. METHODS: A systematic review of English-language studies using the PubMed and EMBASE databases (1990-2009) was performed to retrieve studies that evaluated ETS as a potential risk factor for serious RSV illness. Studies assessing risk factors associated with hospitalization, emergency department visit, or physician visit due to RSV (based on laboratory confirmation of RSV or clinical diagnosis of RSV) in children under the age of 5 years were included. RESULTS: The literature search identified 30 relevant articles, categorized by laboratory confirmation of RSV infection (n = 14), clinical diagnosis of RSV disease (n = 8), and assessment of RSV disease severity (n = 8). Across these three categories of studies, at least 1 type of ETS exposure was associated with statistically significant increases in risk in multivariate or bivariate analysis, as follows: 12 of 14 studies on risk of hospitalization or ED visit for laboratory-confirmed RSV infection; 6 of 8 studies of RSV disease based on clinical diagnosis; and 5 of the 8 studies assessing severity of RSV as shown by hospitalization rates or degree of hypoxia. Also, 7 of the 30 studies focused on populations of premature infants, and the majority (5 studies) found a significant association between ETS exposure and RSV risk in the multivariate or bivariate analyses. CONCLUSION: We found ample evidence that ETS exposure places infants and young children at increased risk of hospitalization for RSV-attributable lower respiratory tract infection and increases the severity of illness among hospitalized children. Additional evidence is needed regarding the association of ETS exposure and outpatient RSV lower respiratory tract illness. Challenges and potential pitfalls of assessing ETS exposure in children are discussed.

An evaluation of a clinical approach to staging tobacco addiction.

OBJECTIVES: To determine whether adolescents' symptom reports are consistent with the developmental sequence of tobacco addiction and whether the sequential appearance of these symptoms signifies increasing addiction. STUDY DESIGN: An anonymous survey was administered to 349 tobacco users in grades 9 through 12 in Florida. The combinations of withdrawal symptoms reported were examined to determine whether they were consistent with the developmental sequence described by case reports (wanting, then craving, then needing). Dependence was measured by several validated measures, including the Hooked on Nicotine Checklist, the Autonomy Over Tobacco Scale, and the modified Fagerström Tolerance Questionnaire. RESULTS: The combinations of withdrawal symptoms reported by 99.4% of subjects were consistent with case reports stating that wanting, craving, and needing develop in that sequence. Across the stages, from wanting to needing, higher stages were associated with significant increases in the strength of addiction as measured by the Hooked on Nicotine Checklist, the Autonomy Over Tobacco Scale, the modified Fagerström Tolerance Questionnaire, and all other measures. CONCLUSIONS: Our data confirmed that withdrawal symptoms develop in an orderly sequence, as proposed, and indicate that each progressive step along the sequence of wanting, craving, and needing represents a substantial increase in tobacco addiction. This provides the foundation for a clinical approach to staging the progression of tobacco addiction.

Children's loss of autonomy over smoking: the Global Youth Tobacco Survey.

BACKGROUND: Empirical data suggest that children with infrequent tobacco use have difficulty quitting smoking. METHODS: Data were obtained from the nationally representative Global Youth Tobacco Survey of middle-school students in Cyprus and Greece. Regression analyses examined associations between smoking frequency (smoking days per month or cigarettes smoked per day) and loss of autonomy (difficulty refraining from smoking). RESULTS: The prevalence of lost autonomy was 40% among subjects who smoked 1 or 2 days/month and 41% among subjects who averaged less than one cigarette/day and increased in a dose-response pattern. Regression models derived from the Cyprus data were replicated by the Greek data. CONCLUSIONS: Two national surveys confirm previous reports of difficulty with smoking cessation with infrequent smoking. Since loss of autonomy is universally recognised as a core feature of addiction, our data indicate that young adolescents experience symptoms of nicotine addiction with infrequent tobacco use.

Electronic Cigarettes Associated With Incident and Polysubstance Use Among Youth.

PURPOSE: Electronic cigarette (e-cigarette) use has increased exponentially among the youth in the United States and may increase the incidence of substance use. METHODS: Youth participants (12-17 years) were surveyed through the Population Assessment of Tobacco and Health study over a three-year time period. Youth with any baseline substance use or diagnosis of an attention deficit disorder were excluded from the analysis. Multivariable logistic regressions were used to assess the association between e-cigarette use at Wave 1 and incident substance use (marijuana, painkillers, sedatives, or tranquilizers and Ritalin/Adderall) and polysubstance use at Wave 2 or 3, and marijuana use in the electronic nicotine device at Wave 3. RESULTS: Baseline ever e-cigarette users who had no history of marijuana, nonprescribed drugs and illicit substance use in Wave 1 had increased odds of reporting incident use of marijuana (odds ratio 2.59, 95% confidence interval: 1.90-3.52), nonprescribed Ritalin/Adderall use (1.89, 1.09-3.28), or polysubstance use (2.09, 1.43-3.05) in Wave 2 or 3 compared to never e-cigarette users. They were also more likely to report use of marijuana in the electronic nicotine product (2.26, 1.56-3.27) in Wave 3 compared to never e-cigarette users. There was no statistically significant association between baseline e-cigarette use and incident use of painkillers, sedatives, or tranquilizers in Wave 2 or 3 (1.21, .79-1.87). CONCLUSIONS: E-cigarette use is associated with incident use of marijuana, marijuana in electronic nicotine devices, Ritalin/Adderall, and polysubstance use but not painkillers, sedatives, or tranquilizers. Results indicate that e-cigarettes are associated with subsequent additional risky health behaviors in youth.

New insights into the compulsion to use tobacco from an adolescent case-series.

Nicotine addiction is the most common preventable cause of premature death presenting during adolescence. No prior study has described the onset of this condition based on case histories. We used trained personnel to conduct individual semi-structured interviews to obtain case histories from 50 adolescent and young adult current and former smokers. Smokers experience a compulsion to use tobacco that spans a spectrum of severity from wanting, to craving, to needing. The compulsion is commonly experienced as originating foreign to the will of the smoker and recurs with a predictable periodicity that determines the latency from smoking one cigarette to wanting, craving or needing another. Novice smokers could experience latencies as lengthy as a few weeks, and more experienced smokers attributed their escalation in smoking frequency to the shortening of their latencies. Wanting, craving or needing tobacco, as described in this study, are pathognomonic for a compulsion to use tobacco.

Thwarting science by protecting the received wisdom on tobacco addiction from the scientific method.

In their commentary, Dar and Frenk call into question the validity of all published data that describe the onset of nicotine addiction. They argue that the data that describe the early onset of nicotine addiction is so different from the conventional wisdom that it is irrelevant. In this rebuttal, the author argues that the conventional wisdom cannot withstand an application of the scientific method that requires that theories be tested and discarded when they are contradicted by data. The author examines the origins of the threshold theory that has represented the conventional wisdom concerning the onset of nicotine addiction for 4 decades. The major tenets of the threshold theory are presented as hypotheses followed by an examination of the relevant literature. Every tenet of the threshold theory is contradicted by all available relevant data and yet it remains the conventional wisdom. The author provides an evidence-based account of the natural history of nicotine addiction, including its onset and development as revealed by case histories, focus groups, and surveys involving tens of thousands of smokers. These peer-reviewed and replicated studies are the work of independent researchers from around the world using a variety of measures, and they provide a consistent and coherent clinical picture. The author argues that the scientific method demands that the fanciful conventional wisdom be discarded and replaced with the evidence-based description of nicotine addiction that is backed by data. The author charges that in their attempt to defend the conventional wisdom in the face of overwhelming data to the contrary, Dar and Frenk attempt to destroy the credibility of all who have produced these data. Dar and Frenk accuse other researchers of committing methodological errors and showing bias in the analysis of data when in fact Dar and Frenk commit several errors and reveal their bias by using a few outlying data points to misrepresent an entire body of research, and by grossly and consistently mischaracterizing the claims of those whose research they attack.

Asking for Identification and Retail Tobacco Sales to Minors.

BACKGROUND AND OBJECTIVES: A previous single-county study found that retail stores usually asked young-looking tobacco customers to show proof-of-age identification, but a large proportion of illegal tobacco sales to minors occurred after the customers had shown identification proving they were too young to purchase tobacco. We sought to investigate these findings on a larger scale. METHODS: We obtained state reports for federal fiscal years 2017 and 2018 from a federal agency that tracks tobacco sales to supervised minors conducting compliance checks in retail stores. We used descriptive and multivariable logistic regression methods to determine (1) how often stores in 17 states requested identifications, (2) what proportion of violations occurred after identification requests, and (3) if violation rates differed when minors were required versus forbidden to carry identification. RESULTS: Stores asked minors for identification in 79.6% (95% confidence interval: 79.3%-80.8%) of compliance checks (N = 17 276). Violations after identification requests constituted 22.8% (95% confidence interval: 20.0%-25.6%; interstate range, 1.7%-66.2%) of all violations and were nearly 3 times as likely when minors were required to carry identification in compliance checks. Violations were 42% more likely when minors asked for a vaping product versus cigarettes. CONCLUSIONS: Stores that sell tobacco to underage customers are more likely to be detected and penalized when youth inspectors carry identification during undercover tobacco sales compliance checks. The new age-21 tobacco sales requirement presents an opportunity to require identifications be carried and address other long-standing weaknesses in compliance-check protocols to help combat the current adolescent vaping epidemic.

Natural Course of Nicotine Dependence Among Adolescent Waterpipe and Cigarette Smokers.

PURPOSE: Waterpipe (WP) smoking patterns and setting can result in a unique trajectory of nicotine dependence (ND) compared with cigarette smoking. This longitudinal study compared the development of ND symptoms among adolescent WP and cigarette smokers. METHODS: A cohort of 647 eighth and ninth graders in Lebanon were followed over 5 years. This study was based on 283 current exclusive WP and 146 current exclusive cigarette smokers. Kaplan-Meier survival analyses were conducted to evaluate 50% cumulative probability for the development of initial Hooked on Nicotine Checklist symptoms and the International Classification of Diseases, 10th revision (ICD-10) ND. RESULTS: An initial Hooked on Nicotine Checklist symptom was endorsed by 59% of WP and 50% of cigarette smokers after smoking onset. Among those, 50% of both WP and cigarette smokers did so within 9.7 and 18.5 months, respectively. Approximately 28% of WP smokers and 22% of cigarette smokers developed ICD-10 ND. Among those, 50% of both WP and cigarette smokers did so within 15 and 22 months, respectively. The most common first to fourth ICD-10 criteria reported by WP smokers were "a strong desire to use tobacco," "difficulties in controlling tobacco taking behavior," "neglect of alternative pleasure," and "use despite harm." The most common first to fourth ICD-10 criteria reported by cigarette smokers were "a strong desire to use tobacco," "difficulties in controlling tobacco taking behavior," "withdrawal," and "tolerance". CONCLUSIONS: Compared with adolescent cigarette smokers, initial ND symptoms and ICD-10 ND can develop sooner after starting to smoke and progress more rapidly among adolescent WP smokers. Developing, implementing, and evaluating intervention programs with adolescent WP smokers should be guided by the WP-specific trajectory of ND.

Predictors of nicotine dependence among adolescent waterpipe and cigarette smokers: A 6-year longitudinal analysis.

OBJECTIVE: Identifying the factors associated with nicotine dependence (ND) is essential to prevent initiation and continued use, and to promote cessation among youth. This study aims to document the predictors of the appearance of initial ND symptoms and full ND syndrome among adolescent waterpipe (WP) and cigarette smokers. METHODS: A 6-year longitudinal study was conducted among 8th and 9th graders from 38 schools in Lebanon. The analysis sample included exclusive-WP (n = 228) and exclusive-cigarette smokers (n = 139). Weighted Cox proportional hazards models were used to characterizing predictors of initial ND symptoms and full ND syndrome. RESULTS: Predictors of experiencing initial ND symptoms among WP smokers included low maternal educational level, having a sibling who smoked WP, low physical activity, high body mass index (BMI), smoking initiation at a younger age. For cigarette smokers these were being male, younger, having lower BMI, having a sibling who smoked cigarettes, living in a crowded household, and smoking daily. Among WP smokers, predictors of developing full ND syndrome include being younger, believing that WP smokers have more friends, depression, high levels of impulsivity, and initiating smoking at a younger age. For cigarette smokers, predictors of full ND syndrome were being younger and initiating smoking at a younger age. CONCLUSION: Smoking cessation and prevention interventions targeting youth should address modifiable, and tobacco use-specific factors that influence the development of ND among young WP and cigarette smokers. They also need to start at a younger age to target those most vulnerable to developing life-long addiction to tobacco products.