Developmental trajectories of criteria of nicotine dependence in adolescence

Subjective effects as predictors of substance use disorders in a clinical sample: A longitudinal study

BACKGROUND

The literature on the association between subjective effects (SEs; i.e., how an individual perceives their physiological and psychological reactions to a drug) and substance use disorders (SUDs) is largely limited to community samples. The present study addressed the following aims in a clinical sample: whether SEs predict general versus substance-specific SUD in adolescence and adulthood after controlling for conduct disorder symptoms (CDsymp); whether SEs predict SUDs across drug classes; whether SEs predict change in SUD from adolescence to adulthood; and whether there are racial/ethnic differences in associations.

METHODS

Longitudinal analyses were conducted using data from a sample of 744 clinical probands recruited from residential and outpatient SUD treatment facilities in CO during adolescence (Mage = 16.26) and re-assessed twice in adulthood (Mages = 22.56 and 28.96), approximately seven and twelve years after first assessment. SEs and CDsymp were assessed in adolescence. SUD severity was assessed at adolescence and twice during adulthood.

RESULTS

SEs assessed in adolescence robustly predicted general SUD for legal and illegal substances in adolescence and adulthood, whereas CDsymp predicted SUD primarily in adolescence. Higher positive and negative SEs in adolescence were associated with greater SUD severity after controlling for CDsymp, with similar magnitudes. Results indicated cross-substance effects of SEs on SUD. We found no evidence for racial/ethnic differences in associations.

CONCLUSIONS

We investigated the progression of SUD in a high-risk sample with greater odds of sustained SUD. In contrast to CDsymp, both positive and negative SEs consistently predicted general SUD across substances in adolescence and adulthood.

Blunt and non-blunt cannabis use associated with cigarette, e-cigarette, and cigar initiation: Findings from the population assessment of tobacco and health (PATH) study

BACKGROUND

Smoking cannabis using a tobacco-derived cigar shell or wrap, called blunt smoking, exposes individuals to non-trivial amounts of nicotine. The extent smoking blunts impact the risk of initiating other tobacco products is not well understood. We investigated if past-year blunt smoking is related to the risk of initiating cigarettes, e-cigarettes, and cigars.

METHODS

We obtained data on a nationally representative, non-institutionalized, civilian cohort of US residents aged 12 years and older who had never used cigarettes, e-cigarettes, or any cigar at baseline and surveyed annually for three years from the Population Assessment of Tobacco and Health Study. We estimated the proportional hazard (odds) of initiating these tobacco products associated with past-year blunt smoking, non-blunt cannabis use, or neither using discrete-time survival analyses.

RESULTS

Smoking blunts increased the risk of starting cigarettes (OR = 4.5), e-cigarettes (OR = 3.7), and cigars (OR = 6.7) compared to using neither blunts nor cannabis. Non-blunt cannabis use also increased the risk of starting cigarettes (OR = 4.0) but moderately for e-cigarettes (OR = 2.8) and any cigar (OR = 2.2). Blunt use was strongly related to starting combustible tobacco (cigarettes or cigars; OR = 9.0) and any three tobacco products (OR = 10.9). Exploratory findings showed that cigarillos drove cigar results and effect modification by age, race/ethnicity, and sex.

CONCLUSIONS

People who smoke blunts risk starting cigarettes, e-cigarettes, and cigars more than those who abstain from cannabis. Blunts may contribute to tobacco initiation above cannabis alone.

Where should I start? A scoping review about the publications on clove cigarettes

INTRODUCTION

The general lack of knowledge about the composition of clove cigarettes and the large number of terms that can be used to define different types of cigarettes that contain cloves makes it difficult to find scientific articles focused on the subject. We reviewed the publications that cited clove cigarettes to assess their relevance.

METHODS

We searched publications on Scopus, ScienceDirect, PubMed, and Portal CAPES during the first semester of 2021, without date restrictions. Through a quality assessment, the studies found were assorted in ten different categories.

RESULTS

Indonesian clove cigarettes-also known as kretek-are a mixture of tobacco and cloves rolled in a cigarette and sprayed with oils, plant extract, and food flavorings, in an unknown quantity and composition, different from each brand, which is usually kept in secret. Due to the relatively low prevalence of use in the general population, most publications on tobacco products tend to ignore clove cigarettes or place them in an existing category. Clove cigarettes can be hand-rolled, machine-made, filtered, unfiltered, and each form can be named differently. The interchangeable use of each term, sometimes grouping conventional cigarettes in the mix, can lead the researcher to consider a publication that should be excluded.

CONCLUSION

The existing regulations on flavored cigarettes, although well-intentioned, are still somewhat vague and broad, leaving possible loopholes that can be exploited by the tobacco industries. Fully understanding the precise effects caused by clove cigarettes can be an important tool in future discussions about tobacco control.

Intergenerational transmission of parental smoking: when are offspring most vulnerable?

BACKGROUND

Previous literature has showed that the likelihood of smoking is higher among offspring with smoking parents. The aim of this cohort study is to investigate during which smoking initiation stages and at what ages adolescents are more likely to be influenced by parental smoking.

METHODS

This study used the EPITeen Cohort, which recruited 13-year-old adolescents born in 1990, enrolled at schools in Porto, Portugal. Participants (n = 996) were followed across four waves at 13, 17, 21 and 24 years old. We computed the odds ratio (OR) and 95% confidence intervals for the prevalence of the different smoking states (never smoking, experimenter, less than daily smoker, daily smoker and former smoker), and incidence transitions between these states (to smoking experimenter; to less than daily smoker, to daily smoker; to former smoker) as function of age, parental smoking status and their interaction.

RESULTS

Compared with other participants, those with two smoking parents had an increased prevalence of experimentation at 13 years (OR for the interaction at 13 years compared with 24 years = 2.13 [1.50-3.01]) and daily smoking at all ages (OR for parental smoking =1.91 [1.52-2.40]). The latter increase is related to a significantly increased risk to transit from early smoking stages to daily smoking at all ages (OR for parental smoking = 1.83 [1.43-2.34]).

CONCLUSIONS

Parental smoking influences offspring's daily smoking prevalence especially by increasing the risk to transit to daily smoking up to early adulthood. Prevention should focus on parents and parental influences especially among offspring who may transition to daily smokers.

Trajectories of Substance Use and Well-being in Early and Middle Adolescence Shaped by Social Connectedness

Increasing substance use and decreasing well-being are typical in adolescence, yet how social contexts shape disparate development during this time is less well-understood. A latent growth class analysis was conducted that identified groups of early (N = 706; Age_m  = 12.20) and middle (N = 666; Age_m  = 14.38) adolescents distinguished by rates of substance use and well-being over three years. In both cohorts, the largest group reported low substance use and high well-being, with a smaller group exhibiting maladaptive trajectories for both substance use and well-being. Two additional groups were identified during middle adolescence characterized by either low well-being or high substance use. Family connectedness was a protective factor, while high peer connectedness was a risk factor for substance-use groups and low peer connectedness for languishing.

A Group-Based Modeling Approach to Identify Developmental Trajectories of Nicotine Dependence Among Lebanese Adolescents Waterpipe Smokers

INTRODUCTION

Adolescence represents a critical period in which nicotine dependence (ND) symptoms are developing. Little is known about waterpipe (WP) smoking and developmental trajectories of ND criteria across adolescence.

AIMS AND METHODS

Here, we aimed to identify ND trajectories from early- to late-adolescence in current (past 30 days) WP smokers and examine baseline correlates of each identified trajectory, using the International Classification of Diseases, 10th Revision (ICD-10). The analytical sample consisted of 278 current WP smokers from eight waves of an ongoing longitudinal cohort of eighth to ninth graders in Lebanon. Group-based trajectory modeling was estimated to identify trajectory classes for ICD-10-ND criteria over ages 11-18.

RESULTS

A group-based modeling approach yielded a four-class solution that best fit the data and reflected differences in the timing of ND onset during adolescence: no-onset of ND (43.9%), early-onset (16.2%), mid-onset (26.6%), and late-onset (13.3%) of ND criteria. Having a less-educated mother (adjusted odds ratio [aOR] = 4.08, 95% confidence interval [95% CI] = 1.01% to 16.53%) and siblings who smoke WP (aOR = 3.95, 95% CI = 1.08% to 14.42%), exposure to favorite WP-specific advertisements (aOR = 3.33, 95% CI = 1.03% to 10.85%), and being a novelty seeker (aOR = 1.12, 95% CI = 1.02% to 1.23%) were associated with early-onset of ND. Daily (aOR = 3.48, 95% CI = 1.08% to 11.23%) or weekly (aOR = 2.20, 95% CI = 1.05% to 4.62%) WP smokers (vs. monthly) and having higher stress level (aOR = 1.07, 95% CI = 1.00% to 1.14%) were associated with mid-onset trajectory. Believing that WP smoking is not harmful to health (aOR = 0.11, 95% CI = 0.02% to 0.82%) and spending less than 60 minutes on a WP smoking session (aOR = 5.62, 95% CI = 1.20% to 26.44%) were associated with late-onset ND trajectory class.

CONCLUSIONS

Monitoring the development of ND trajectories among WP smokers may identify an individual as belonging to one of these four groups with distinct individual and socioenvironmental factors and allow the individual and health care providers opportunities to inform initiate on-time WP-specific tailored prevention and cessation interventions.

IMPLICATIONS

The results from this study showed a four-class trajectory of ICD-10-ND criteria and suggested that every ND trajectory class during adolescence could have distinctive characteristics and therefore provides new insights into the process of ND in terms of when and what specific interventions are needed to curb the development of ND and long-term WP smoking among youth.

Spatio-temporal parse network-based trajectory modeling on the dynamics of criminal justice system

We extend the existing group-based trajectory modeling by proposing the network-based trajectory modeling based on judicious design and analysis of a spatio-temporal parse network (STPN) as a representation of neighborhood structure that evolves in time. The STPN offers a principled qualitative specification for an explicit paradigm framework to deal with complex real-world problems. The framework is completed by developing a quantitative specification of latent field representation to merge seamlessly on or alongside the established STPN via hierarchical modeling. The models adopt spatial random effects to characterize the heterogeneity and autocorrelation over the locations where nonlinear trajectories were observed. The trajectories are then investigated in the presence of the operational constraints of the dependence structure induced by the spatial and temporal dimensions. With the framework, complex developmental trajectory problems can be discerned, communicated, diagnosed and modeled in a relatively simple way that interpretation is accessible to nontechnical audiences and quickly comprehensible to technically sophisticated audiences. The proposed modeling is applied to address the challenges of the trajectory modeling of nonlinear dynamics arising from a motivating criminal justice empirical process.

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.

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.

Blunt and Non-Blunt Cannabis Use and Risk of Subsequent Combustible Tobacco Product Use Among Adolescents

INTRODUCTION

Cannabis-including blunts (cannabis rolled in tobacco-containing cigar casing) -is commonly the first substance used among adolescents and may increase the likelihood of subsequent initiation of combustible tobacco products.

AIMS AND METHODS

Data were pooled from two prospective studies of adolescents in California and Connecticut (total N = 4594). Logistic regression models assessed the association of baseline ever blunt use and ever non-blunt cannabis use (vs. never cannabis use) with subsequent initiation of any combustible tobacco-only product (ie, cigarettes, cigars, or cigarillos) by 1-year follow-up after adjustment for demographic characteristics and other tobacco product use at baseline. We also assessed whether estimates differed by prior e-cigarette or hookah use at baseline.

RESULTS

Among never combustible tobacco-only product users (N = 2973), 221 (7.4%) had ever used a blunt and 114 (3.8%) had ever used only non-blunt cannabis at baseline. Blunt use (adjusted odds ratio [AOR] = 1.98, 95% confidence interval [CI]: 1.30 to 3.01) and non-blunt cannabis use (AOR = 2.38, 95% CI: 1.41 to 4.00) were independently associated with greater odds of combustible tobacco-only product initiation by follow-up. Among those who had not tried e-cigarettes or who had not tried hookah, blunt use and non-blunt cannabis use were associated with significantly increased odds of combustible tobacco product initiation; among those who had tried e-cigarettes or hookah, the association was not significant.

CONCLUSIONS

We found blunt and non-blunt cannabis use to be associated with subsequent combustible tobacco-only product initiation, particularly among adolescents who had not also tried other products containing nicotine.

IMPLICATIONS

Adolescent-focused tobacco prevention efforts should consider incorporating cannabis products, including blunts. More research is needed to understand how blunt use and cannabis use more broadly are associated with initiation of tobacco products.

The Relationship Between Tobacco and Cannabis Use: A Review

BACKGROUND

Based on the prevalence and health implications of tobacco and cannabis use, aiming to reduce their use, especially among youth, is a sound objective at both the individual and public health level. A proper understanding of the relationships between tobacco and cannabis use may help to achieve this goal.

OBJECTIVES

To review the relationships between tobacco and cannabis use.

METHODS

A selective review of the literature.

RESULTS

We present an overview of the motivations for tobacco and cannabis use, and their perceived harmfulness. The article then reviews the gateway theory, reverse gateway theory, route of administration theory, and common liability theory. We describe the link between co-use and dependence symptoms, and the substitution phenomenon between tobacco and cannabis use. Three forms of simultaneous use-mulling, blunt smoking, and chasing-and their impacts are explained. We summarize the impact of tobacco use on cannabis (and vice versa) treatment outcomes, and, finally, review new treatments that simultaneously target tobacco and cannabis dependence. Most of the literature reviewed here relates to substance use among adolescents and young adults.

CONCLUSIONS

The use of tobacco and cannabis-two of the most widely used substances around the world-are strongly intertwined in several respects. Both health professionals and researchers should have well-informed views on this issue to better evaluate, understand, inform, and provide care to their patients.

Co-use of cannabis, tobacco, and alcohol during adolescence: policy and regulatory implications

Legislative reforms have legalized use of cannabis for medical and recreational purposes. Efforts to evaluate the public health impact of these changes have predominantly focused on determining whether liberalizing cannabis policies has increased cannabis use patterns. Co-use of cannabis and other licit substances, namely tobacco and alcohol, is common during the developmental period of adolescence, which is generally characterized by an increase in risk-taking and novelty-seeking. However, limited research has sought to evaluate the potential implications of reforms to medical and recreational cannabis laws on concurrent and simultaneous use of cannabis, tobacco, and alcohol during adolescence. The current report reviews the extant literature detailing the prevalence and outcomes associated with concurrent and simultaneous cannabis-tobacco and cannabis-alcohol use, including recent work that has examined how concurrent and simultaneous use may be influenced by cannabis reform. This review details how the cannabis landscape and cannabis retail marketplace have evolved and briefly summarizes the corresponding policy and regulatory challenges that have emerged. The report concludes with a focused cannabis co-use research agenda that adopts different strategies including behavioural economic, self-administration, and survey research methods.

A longitudinal study of the reciprocal relationship between ever smoking and urgency in early adolescence

BACKGROUND

Among early adolescents in the United States (U.S.), the prevalence of cigarette smoking is at its lowest level in recent decades. Nonetheless, given the risks of smoking in early development, it remains critically important to study both risk factors for smoking and risks from smoking. This longitudinal study with U.S. early adolescents examines smoking initiation and tests a model of reciprocal prediction between ever smoking and the personality trait of urgency (i.e., mood-based impulsivity), a trait that increases risk for multiple forms of dysfunction.

METHODS

Participants (n=1906; 90% 10-11 years old, 50% female, 39% racial minorities at baseline) completed questionnaires 1-2 times per year starting in 5th grade and ending in 9th grade. Structural equation modeling allowed tests of bidirectional relationships between ever smoking and urgency controlling for pubertal status and negative affect at each wave.

RESULTS

Incidence of ever smoking increased from 5% to 27% over time, with current smoking around 5% at the last wave. Urgency at each wave predicted ever smoking at the next wave above and beyond covariates and prior smoking (all p<0.01). Likewise, with one exception, ever smoking predicted an increase in urgency at the subsequent wave above and beyond covariates and prior urgency (all p<0.05).

CONCLUSION

Results show that risk for smoking increases with higher levels of urgency and urgency increases secondary to engagement in smoking. Future work should therefore explore urgency as a point of prevention for smoking and smoking cessation as a means to mitigate mood-based impulsivity.

Longitudinal HIV Care Trajectories in North Carolina

BACKGROUND

Long-term HIV care and treatment engagement is required for maximal clinical and prevention benefits, but longitudinal care patterns are poorly understood. We used the last 10 years' worth of HIV surveillance data from North Carolina to describe longitudinal HIV care trajectories from diagnosis.

METHODS

We conducted a retrospective, population-based cohort study of all persons newly diagnosed with HIV in North Carolina between March 31, 2006 and March 31, 2015 (N = 16,207). We defined HIV care attendance in each 3-month and 6-month interval after diagnosis as the presence of viral load and/or CD4 records (care visit proxies) in the interval. We used group-based trajectory modeling to identify common care trajectories and baseline predictors thereof.

RESULTS

A predicted 26% of newly HIV-diagnosed persons showed consistently high care attendance over time; ∼16% exhibited steadily declining attendance; ∼26% showed consistently low attendance; ∼17% had initially weak attendance with an increase starting ∼1.5 year later; and ∼15% showed initially weak attendance with an increase starting ∼3 years later. Older age at diagnosis was protective against all suboptimal trajectories (with the "consistently high" pattern as referent), and being a man who has sex with men was protective against 3 of the 4 suboptimal patterns.

CONCLUSIONS

As measured by surveillance-based laboratory proxies, most newly HIV-diagnosed persons exhibited suboptimal care trajectories, but there was wide variation in the particular pathways followed. The insights provided by this analytical approach can help to inform the design of epidemic models and tailored interventions, with the ultimate goal of improving HIV care engagement and transmission prevention.

Life Course Changes in Smoking by Gender and Education: A Cohort Comparison Across France and the United States

Widening of educational disparities and a narrowing female advantage in mortality stem in good part from disparities in smoking. The changes in smoking and mortality disparities across cohorts and countries have been explained by an epidemic model of cigarette use but are also related to life course changes. To better describe and understand changing disparities over the life course, we compare age patterns of smoking in three cohorts and two nations (France and the United States) using smoking history measures from the 2010 French Health Barometer (N = 20,940) and the 2010 U.S. National Health Interview Survey Sample Adult File (N = 20,444). The results demonstrate statistically significant widening of gender and educational differences from adolescence to early and middle adulthood, thus accentuating the disparities already emerging during adolescence. In addition, the widening disparities over the life course have been changing across cohorts: Age differences in educational disparities have grown in recent cohorts (especially in France), while age differences in gender disparities have narrowed. The findings highlight the multiple sources of inequality in smoking and health in high-income nations.

Marijuana and tobacco co-administration in blunts, spliffs, and mulled cigarettes: A systematic literature review

BACKGROUND

Blunts and spliffs/mulled cigarettes combine marijuana and tobacco for co-administration (use at the same time, in the same product). Co-administration of marijuana and tobacco presents significant potential for nicotine exposure, and may lead to exclusive tobacco use patterns, nicotine addiction, and compounded health effects. No review articles have summarized the number and nature of studies published on these co-administered products.

METHODS

Keywords "(blunt* OR spliff OR mull* OR joint) AND (tobacco OR smok* OR cigarette) AND (cannabis OR marijuana OR hashish)" were searched in the published literature. A total of 220 articles were considered for inclusion, 49 were reviewed by two independent qualitative coders, and 45 were included in this review.

RESULTS

Of the 45 articles, most (n=27) of studies were observational or descriptive; ten were qualitative, five employed causal designs, and three were mixed methods. A majority of the studies assessed blunts; only 11 studies assessed spliffs/mulled cigarettes. Many studies focused on sub-populations of youth, males, and African Americans. Use of co-administered marijuana and tobacco products was associated with several indicators of problematic use patterns, including perceptions of less risk, dependence on nicotine and marijuana, and greater subjective effects related to marijuana.

CONCLUSIONS

Literature on marijuana and tobacco co-administration comes largely from qualitative and observational/descriptive studies. In addition to continued surveillance, experimental research that directly assesses the smoking patterns of co-administered marijuana and tobacco products as compared with to those of marijuana and tobacco only products is needed to determine the potential long-term health consequences of using blunts, spliffs, or other co-administered products.

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.

Trajectories of injecting behavior in the Amsterdam Cohort Study among drug users

BACKGROUND

Injecting frequency among people who inject drugs (IDU) can change along distinct trajectories, which can reflect on incidence of HIV and HCV infections. We aimed at assessing these patterns of longitudinal changes, their predictors and their association with the incidence of HIV and HCV.

METHODS

We analyzed data from the Amsterdam Cohort Study among Drug Users, selecting participants recruited from 1985 to 2005, injecting drugs before cohort entry and with records in at least three different six months intervals (N=740). We used latent class mixed models to identify distinct trajectories of injecting, multinomial regression to identify socio-demographic variables associated with those patterns and Kaplan-Meier analysis for the estimation of the corresponding cumulative HIV and HCV incidence.

RESULTS

Five distinct patterns for injecting frequency and for injecting since last visit were identified. The majority of participants (three groups, 69% of participants) had stable risk injecting behavior; the remaining displayed a decrease in injecting over time. Those with longer duration of injecting at cohort entry and those who entered the cohort in earlier years tended to have continuing high risk behavior. The HIV risk was highest among those with continuing high risk behavior and its changes over time mirrored the patterns of change in injecting in a group with decrease in injecting.

CONCLUSIONS

Individual longitudinal patterns of changes in injecting behavior are related to socio-demographic and drug use variables and are reflected in the incidence of HIV infections. Understanding these associations might provide valuable information for targeted interventions.

Reciprocal associations between cigarette consumption and DSM-IV nicotine dependence criteria in adolescent smokers

AIMS

To examine the inter-relationships between cigarette consumption and DSM-IV nicotine dependence (ND) criteria from smoking onset in adolescence up to 7 years later, adjusting for alcohol consumption and DSM-IV alcohol dependence (AD) criteria.

DESIGN

A cohort drawn from grades 6-10 in an urban school system was interviewed five times at 6-month intervals (waves 1-5) and 4.5 years later (wave 6). A parent was interviewed three times.

SETTING

Chicago, Illinois.

PARTICIPANTS

Recent smokers (n = 409).

MEASUREMENTS

Structured household interviews ascertained number of cigarettes smoked, DSM-IV ND symptoms, drinks consumed, DSM-IV AD symptoms, and selected covariates. Reciprocal prospective associations between number of cigarettes smoked and ND criteria, controlling for time-varying alcohol consumption and dependence criteria, were examined with cross-lagged models.

FINDINGS

Reciprocal associations between number of cigarettes smoked and ND criteria were both significant. Cigarette consumption had stronger associations with later ND [β = 0.25, 95% confidence interval (CI) = 0.17-0.32] than dependence had with later cigarette consumption (β = 0.09, 95% CI = 0.01-0.16). Alcohol and cigarette consumption influenced each other; AD scores were associated with later ND scores but not the reverse. Reports of pleasant initial experiences from smoking were associated positively with cigarette consumption and ND the first year after smoking onset; later smoking onset was negatively associated with cigarette consumption the seventh year after onset; parental ND predicted cigarette consumption and ND throughout.

CONCLUSIONS

In adolescent smokers, higher cigarette consumption predicts later severity of DSM-IV nicotine dependence more than the reverse. Smoking and drinking also influence each other mutually over time.

Predictors of adolescent smoking cessation and smoking reduction

OBJECTIVE

To investigate the processes of change, demographic, health- and smoking-related predictors of both smoking cessation and smoking reduction in adolescents.

METHODS

Data were drawn from a sample of 755 adolescent smokers who participated in a study testing the efficacy of a text messaging-based intervention for smoking cessation. Demographic, health- and smoking-related variables were assessed at baseline. Five processes of smoking cessation, derived from the Transtheoretical Model and the Social Cognitive Theory, as well as outcome measures were assessed at 6-month follow up. Univariate and multivariate regression analyses were conducted to identify baseline and process variables to predict smoking abstinence and smoking reduction.

RESULTS

Male gender (OR=0.43, p<.01), lower alcohol consumption (OR=0.90, p=.05) and a lower number of cigarettes smoked per day at baseline (OR=0.87, p<.01) predicted smoking abstinence. Baseline physical activity predicted smoking reduction (OR=1.04, p=.03). None of the examined process variables significantly predicted smoking abstinence. The process variable "counter-conditioning" predicted smoking reduction (OR=1.46, p=.03).

CONCLUSIONS

Baseline predictors of smoking cessation differ from predictors of smoking reduction. Dynamic or modifiable variables play an important role in predicting adolescent smoking cessation.

PRACTICE IMPLICATIONS

Counter-conditioning might be an important element in adolescent smoking cessation interventions.

Life course transitions in early adulthood and SES disparities in tobacco use

A huge literature has documented adult socioeconomic disparities in smoking but says less about how these disparities emerge over the life course. Building on findings that smoking among adolescents differs only modestly by parental SES, we utilize a life course perspective on social differentiation to help explain the widening disparities in smoking in young adulthood. Our theory suggests that achieved socioeconomic status and the nature and timing of adult role transitions affect age-based trajectories of smoking and widen disparities in adult smoking. The analyses use data from the National Longitudinal Study of Adolescent Health, which follows a representative national sample over four waves from ages 11-17 in 1994/1995 to 26-34 in 2007/2008. The results show divergent age trajectories in smoking by parental education and that achieved socioeconomic status and life course roles in young adulthood account in good part for differences in the age trajectories. The findings demonstrate the value of the life course perspective in understanding processes of increasing stratification in health behavior and health during the transition to adulthood.

The developmental psychopathology of alcohol use and alcohol disorders: research achievements and future directions

The last 25 years have seen significant advances in our conceptualization of alcohol use and alcohol use disorders within a developmental framework, along with advances in our empirical understanding that have been potentiated by advances in quantitative methods. These include advances in understanding the heterogeneity of trajectories of alcohol outcomes; new insights about early childhood antecedents, and adolescence and emerging adulthood as important developmental periods for alcohol outcomes; a more nuanced understanding of the influences of developmental transitions, and their timing and contexts; a greater appreciation for the importance of considering multiple levels of analysis (including an increasing number of genetically informative studies); a continuing focus on studying multiple pathways underlying alcohol outcomes; and an increasing focus on studying the effects of alcohol exposure on future development. The current paper reviews these advances and suggests directions for future study.

The developmental psychopathology of alcohol use and alcohol disorders: research achievements and future directions

The last 25 years have seen significant advances in our conceptualization of alcohol use and alcohol use disorders within a developmental framework, along with advances in our empirical understanding that have been potentiated by advances in quantitative methods. These include advances in understanding the heterogeneity of trajectories of alcohol outcomes; new insights about early childhood antecedents, and adolescence and emerging adulthood as important developmental periods for alcohol outcomes; a more nuanced understanding of the influences of developmental transitions, and their timing and contexts; a greater appreciation for the importance of considering multiple levels of analysis (including an increasing number of genetically informative studies); a continuing focus on studying multiple pathways underlying alcohol outcomes; and an increasing focus on studying the effects of alcohol exposure on future development. The current paper reviews these advances and suggests directions for future study.

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.

Mental disorders and smoking trajectories: a 10-year prospective study among adolescents and young adults in the community

BACKGROUND

Numerous studies have documented an association between mental disorders and onset of cigarette smoking. Yet, there is little understanding of the potential impact of mental disorders on trajectories of smoking over time. The objective of this study was to investigate this relationship among adolescents over a 10-year span.

METHODS

Data were drawn from the Early Developmental Stages of Psychopathology Study, a 10-year prospective investigation of youth in Germany. Growth mixture modeling was used to identify smoking trajectories and logistic regression analyses were used to examine relationships between mental disorders and subsequent trajectories.

RESULTS

Four trajectories were identified: non-users; increasing use; decreasing use; persistent use. Alcohol/drug use disorders, stress disorders, anxiety disorders, somatoform disorder and nicotine dependence were associated with nicotine use (as compared to the non-smoker class). However, comparisons between trajectories of nicotine use showed that any stress disorder predicted only decreasing use compared to the other two trajectories; nicotine dependence, alcohol/illicit drug use disorders as well as panic disorder and somatoform disorders were inversely associated with increasing use; nicotine dependence and alcohol/drug use disorders were associated with persistent use.

CONCLUSIONS

Several mental disorders appear to be non-specific markers of the range of smoking trajectories while others predict specific trajectories. Numerous disorders (e.g., alcohol/drug use disorders) do not appear to occur only prior to and predict increased smoking trajectory as had been previously suggested, but rather they also occur concurrently, with high levels of smoking and in some cases smoking persists at a steady level over time.

Time-varying effects of smoking quantity and nicotine dependence on adolescent smoking regularity

BACKGROUND

Little is known about time-varying effects of smoking quantity and nicotine dependence on the regularity of adolescent smoking behavior.

METHODS

The sample was drawn from the Social and Emotional Contexts of Adolescent Smoking Patterns Study which followed adolescent smokers over 5 assessment waves spanning 48 months. Participants included former experimenters (smoked <100 cigarettes/lifetime but did not smoke in past 90 days), recent experimenters (smoked <100 cigarettes/lifetime and smoked in past 90 days), and current smokers (smoked >100 cigarettes/lifetime and smoked in past 30 days). Mixed-effects regression models were run to examine the time-varying effects of smoking quantity and nicotine dependence on regularity of smoking behavior, as measured by number of days smoked.

RESULTS

Smoking quantity and nicotine dependence were each found to be significantly associated with regularity of adolescent smoking and the size of each effect exhibited significant variation over time. The effect of smoking quantity decreased across time for each smoking group, while the effect of nicotine dependence increased across time for former and recent experimenters. By the 48-month follow-up, the effects of smoking quantity and nicotine dependence had each stabilized across groups.

CONCLUSIONS

This study reveals that smoking quantity and nicotine dependence are not static risk factors for the development of more regular smoking patterns. At low levels of smoking when nicotine dependence symptoms are less common, smoking quantity is a stronger predictor of increased regularity of smoking, while for more experienced smokers, nicotine dependence predicts further increases in regularity.

Group-based trajectory modeling: a novel approach to examining symptom trajectories in acute bipolar episodes

BACKGROUND

Pattern analysis can aid understanding of trajectories of symptom evolution. However, most studies focus on relatively homogeneous disorders with a restricted range of outcomes, prescribed a limited number of classes of medication. We explored the utility of pattern analysis in defining short-term outcomes in a heterogeneous clinical sample with acute bipolar disorders.

METHOD

In a naturalistic observational study, we used Group-based trajectory modeling (GBTM) to define trajectories of symptom change in 118 bipolar cases recruited during an acute DSM IV episode: major depression (56%), (hypo)mania (26%), and mixed states (18%). Symptoms were assessed weekly for a month using the MATHYS, which measures symptoms independent of episode polarity.

RESULTS

Four trajectories of symptom change were identified: Persistent Inhibition, Transient Inhibition, Transient Activation and Over-activation. However, counter to traditional predictions, we observed that bipolar depression shows a heterogeneous response pattern with cases being distributed approximately equally across trajectories that commenced with inhibition and activation.

LIMITATIONS

The observational period focuses on acute outcomes and so we cannot use the findings to predict whether the trajectories lead to stable improvement or whether the clinical course for some clusters is cyclical. As in all GBTM, the terms used for each trajectory are subjective, also the modeling programme we used assumes dropouts are random, which is clearly not always the case.

CONCLUSION

This paper highlights the potential importance of techniques such as GBTM in distinguishing the different response trajectories for acutely ill bipolar cases. The use of the MATHYS provides further critical insights, demonstrating that clustering of cases with similar response patterns may be independent of episodes defined by mood state.

Trajectories of criteria of nicotine dependence from adolescence to early adulthood

BACKGROUND

To identify patterns and correlates of developmental trajectories of DSM-IV nicotine dependence criteria from adolescence to early adulthood.

METHODS

The analytical sample of lifetime smokers (N=877) is from a longitudinal cohort of 6th-10th graders drawn from an urban school system. Subjects were interviewed 5 times at 6-month intervals and once 4.5 years later. Growth mixture models were estimated to identify trajectories of DSM-IV nicotine dependence criteria over ages 12-23.

RESULTS

A four-class solution fitted the data best: No dependence criteria (class 1, 32.0%); early onset/chronic course (class 2, 26.1%); early onset/remission (class 3, 15.4%); late onset (class 4, 26.5%). There appeared to be three critical periods. At ages 12-15, symptoms increased rapidly. As of age 16, the early onset/chronic class stabilized at high levels of symptoms, the early onset/remission class started its symptomatic decline, and the late onset class experienced a sharp increase in symptoms. At age 20, there was a convergence in the prevalence of symptoms experienced at high (classes 2 and 4) and low levels (classes 1 and 3). Extensiveness of smoking and marijuana use were associated with higher baseline levels of nicotine dependence criteria. Anxiety disorders were associated with all three symptomatic trajectories. Parental smoking and nicotine dependence were associated specifically with the early/chronic class, while pleasant initial sensitivity and earlier onset ages of cigarette and marijuana use characterized the two early onset classes (2 and 3).

CONCLUSIONS

Trajectories of dependence criteria constitute an advantageous phenotype for research and intervention over static summaries of smoking behaviors.

Adolescent nicotine dependence symptom profiles and risk for future daily smoking

Recent research on adolescent smokers suggests that there are important differences in the types of nicotine dependence (ND) symptoms that emerge and different patterns of ND symptoms. The purpose of this study was to use data from the longitudinal Social and Emotional Contexts of Adolescent Smoking Patterns Study to identify latent subgroups of adolescent experimental and nondaily smokers varying in number and types of endorsed ND symptoms. Profiles were identified using baseline level of smoking, individual patterns of ND symptoms and other ND risk factors. Discrete time survival analysis was used to examine profile differences in probability of becoming daily smokers 48 months later. Four distinct subgroups of smokers with different patterns of smoking behavior, ND symptoms, and alcohol and other substance use emerged. Heavier smoking adolescents with high symptom endorsement, particularly the need to smoke in the morning, were most likely to become daily smokers 48 months later. A subgroup of social smokers had high smoking exposure and symptom endorsement (except need to smoke in the morning), and high levels of other substance use. Despite lower rates of smoking frequency and quantity compared to the heavier smoking class, 36% of these adolescents smoked daily by 48 months, with a steeper decline in survival rates compared to other lighter smoking classes. Morning smoking symptoms and symptoms prioritizing smoking (i.e., choosing to spend money on cigarettes instead of lunch or smoking when ill or where smoking is forbidden) might quickly identify adolescent non-daily smokers with more severe dependence and higher risk for daily smoking. A focus on skills for avoiding social situations involving use of alcohol and other drugs and reducing peer smoking influences may be an important focus for reducing smoking and other substance use among social smokers.

Role of endothelin-1 in human aneurysmal subarachnoid hemorrhage: associations with vasospasm and delayed cerebral ischemia

BACKGROUND

Endothelin-1 (ET-1) is a potent vasoconstrictor implicated in the pathogenesis of vasospasm and delayed cerebral ischemia (DCI) in aneurysmal subarachnoid hemorrhage (aSAH) patients. The aim of this study was to investigate the relationship between cerebrospinal fluid (CSF) ET-1 levels and angiographic vasospasm and DCI.

METHODS

Patients with aSAH were consented (n = 106). Cerebral vasospasm was determined by angiography. DCI was determined by transcranial Doppler (TCD) results and/or angiogram results with corresponding clinical deterioration. CSF ET-1 levels over 14 days after the initial insult was quantified by ELISA. ET-1 analysis included a group-based trajectory analysis and ET-1 exposure rate during 24, 48, and 72 h prior to, as well as 72 h post angiography, or clinical deterioration.

RESULTS

Trajectory analysis revealed two distinct groups of subjects with 56% of patients in the low ET-1 trajectory group (mean at day 1 = 0.31 pg/ml; SE = 0.04; mean at day 14 = 0.41 pg/ml; SE = 0.15) and 44% of patients in the high ET-1 trajectory group (mean at day 1 = 0.65 pg/ml; SE = 0.08; mean at day 14 = 0.61 pg/ml; SE = 0.06). Furthermore, we observed that ET-1 exposure rate 72 h before angiography and clinical spasm was a significant predictor of both angiographic vasospasm and DCI, whereas, ET-1 exposure after angiography and clinical spasm was not associated with either angiographic vasospasm or DCI.

CONCLUSION

Based on these results we conclude that ET-1 concentrations are elevated in a sub-group of patients and that the acute (72 h prior to angiography and clinical neurological deterioration), but not chronic, elevations in CSF ET-1 concentrations are indicative of the pathogenic alterations of vasospasm and DCI in aSAH patients.

The role of friends' disruptive behavior in the development of children's tobacco experimentation: results from a preventive intervention study

Having friends who engage in disruptive behavior in childhood may be a risk factor for childhood tobacco experimentation. This study tested the role of friends' disruptive behavior as a mediator of the effects of a classroom based intervention on children's tobacco experimentation. 433 Children (52% males) were randomly assigned to the Good Behavior Game (GBG) intervention, a universal preventive intervention targeting disruptive behavior, and facilitating positive prosocial peer interactions. Friends' disruptive behavior was assessed from age 7-10 years. Participants' experimentation with tobacco was assessed annually from age 10-13. Reduced rates in tobacco experimentation and friends' disruptive behavior were found among GBG children, as compared to controls. Support for friends' disruptive behavior as a mediator in the link between intervention status and tobacco experimentation was found. These results remained after controlling for friends' and parental smoking status, and child ADHD symptoms. The results support the role of friends' disruptive behavior in preadolescents' tobacco experimentation.

Alcohol use trajectories and the ubiquitous cat's cradle: cause for concern?

In recent years, trajectory approaches to characterizing individual differences in the onset and course of substance involvement have gained popularity. Previous studies have sometimes reported 4 prototypic courses: (a) a consistently "low" group, (b) an "increase" group, (c) a "decrease" group, and (d) a consistently "high" group. Although not always recovered, these trajectories are often found, despite these studies varying in the ages of the samples studied and the duration of the observation periods employed. Here, the authors examined the consistency with which these longitudinal patterns of heavy drinking were recovered in a series of latent class growth analyses that systematically varied the age of the sample at baseline, the duration of observation, and the number and frequency of measurement occasions. Data were drawn from a 4-year, 8-wave panel study of college student drinking (N = 3,720). Despite some variability across analyses, there was a strong tendency for these prototypes to emerge regardless of the participants' age at baseline and the duration of observation. These findings highlight potential problems with commonly employed trajectory-based approaches and the need to not over-reify these constructs.

Uncovering multiple pathways to substance use: a comparison of methods for identifying population subgroups

This paper describes and compares a selection of available modeling techniques for identifying homogeneous population subgroups in the interest of informing targeted substance use intervention. We present a nontechnical review of the common and unique features of three methods: (a) trajectory analysis, (b) functional hierarchical linear modeling (FHLM), and (c) decision tree methods. Differences among the techniques are described, including required data features, strengths and limitations in terms of the flexibility with which outcomes and predictors can be modeled, and the potential of each technique for helping to inform the selection of targets and timing of substance intervention programs.

Smoking behaviours and contextual influences on adolescent nicotine dependence

OBJECTIVE

The objectives of the study were to analyse nicotine-dependence patterns among secondary school students in New Zealand (NZ), and identify factors associated with levels of nicotine dependence.

METHOD

This study uses data from the 2004 Youth Lifestyle Study, a survey of Year 10 and 12 students from randomly selected schools in NZ. The analysis included 625 current adolescent smokers. Nicotine dependence was measured with the Hooked on Nicotine Checklist (HONC). Potential dependence-associated factors studied include: socio-demographic factors; smoking behaviours; and smoking contexts.

RESULTS

A large percentage (87.9%) of the current adolescent smokers reported at least one HONC symptom, with a mean HONC score of 4.9 out of a possible 10. Multivariate analyses identified: school decile; age at which started smoking monthly; lifetime cigarette consumption; and peers smoking as statistically significant predictors of nicotine dependence.

CONCLUSIONS

Adolescent smokers are very likely to become dependent on nicotine. Students from the highest school decile had markedly lower HONC scores. Earlier onset of monthly smoking, heavier overall consumption and peers smoking were associated with higher HONC scores. These findings provide important insights into factors that may need to be modified to help reduce nicotine dependence among adolescents.

Common and drug-specific genetic influences on subjective effects to alcohol, tobacco and marijuana use

AIM

To examine variation in positive and negative subjective effects to alcohol, tobacco and marijuana and covariation between these three drugs and each effect.

DESIGN

Retrospective self-reports of subjective effects were collected to estimate the genetic and environmental influences and the extent of their specificity across three drugs.

PARTICIPANTS

Data were drawn from 1299 adolescent and young adult same- and opposite sex twin- and sibling-pairs participating in the Colorado Center for Antisocial Drug Dependence (CADD).

SETTING

A large, collaborative, longitudinal study of substance use and antisocial behavior in community and clinical adolescents.

MEASUREMENT

  Subjective effects were assessed using a 13-item questionnaire that included positive and negative responses to alcohol, tobacco and marijuana.

FINDINGS

Heritable influences contributed moderately (additive genetic effects 16-56%) to positive and negative subjective effects to all three drugs and did not differ for males and females. Genetic and environmental contributions to positive and negative subjective effects are largely non-overlapping for tobacco and marijuana. Multivariate genetic modeling indicated that subjective effects to alcohol, tobacco and marijuana share a common, heritable etiology and that drug-specific genetic influences were an important contributor to individual differences in drug response.

CONCLUSIONS

  Results from our genetic analyses suggest that subjective effects to these commonly used and misused drugs are heritable and that the genetic and environmental influences on effects to one drug also influence subjective effects to other drugs.

How spacing of data collection may impact estimates of substance use trajectories

The goal of this study is to provide an empirical example using longitudinal cigarette smoking data that compares results of growth mixture trajectory models on the basis of contiguous and snapshot measurements. Data were drawn from an intensive longitudinal study of college freshman (N = 905) with a previous history of smoking. Participants provided weekly smoking reports for 35 consecutive weeks. We found that using contiguous weekly data (35 waves) or 6-wave or 4-wave snapshot data provided similar trajectory curves and proportions. However, there were notable differences in individual trajectory assignments on the basis of contiguous and snapshot measurements.

Can one puff really make an adolescent addicted to nicotine? A critical review of the literature

Rationale

In the past decade, there have been various attempts to understand the initiation and progression of tobacco smoking among adolescents. One line of research on these issues has made strong claims regarding the speed in which adolescents can become physically and mentally addicted to smoking. According to these claims, and in contrast to other models of smoking progression, adolescents can lose autonomy over their smoking behavior after having smoked one puff in their lifetime and never having smoked again, and can become mentally and physically "hooked on nicotine" even if they have never smoked a puff.

Objectives

To critically examine the conceptual and empirical basis for the claims made by the "hooked on nicotine" thesis.

Method

We reviewed the major studies on which the claims of the "hooked on nicotine" research program are based.

Results

The studies we reviewed contained substantive conceptual and methodological flaws. These include an untenable and idiosyncratic definition of addiction, use of single items or of very lenient criteria for diagnosing nicotine dependence, reliance on responders' causal attributions in determining physical and mental addiction to nicotine and biased coding and interpretation of the data.

Discussion

The conceptual and methodological problems detailed in this review invalidate many of the claims made by the "hooked on nicotine" research program and undermine its contribution to the understanding of the nature and development of tobacco smoking in adolescents.

Do early smoking experiences count in development of smoking?: temporal stability and predictive validity of an early smoking experience questionnaire in adolescents

AIMS

The experience during initial experimentation with smoking might influence later development of smoking behavior; however, measuring early smoking experience (ESE) usually requires self-reports for which stability and predictive validity are relatively understudied. The aims of the study are (a) to examine temporal stability of the ESE questionnaire and (b) to test the hypothesis that early pleasant and unpleasant experience scales predict changes in smoking status among adolescents.

METHODS

In two waves of the Budapest Adolescent Smoking study, a school-based longitudinal study, 1,286 ninth-grade students reported their ESE on both occasions (45.9% girls; mean age = 15.3, SD = 0.54). Questions related to smoking behavior and ESEs were administered in both waves (average 5 month apart). To examine temporal stability, test-retest correlations and a multiindicator autoregressive model were estimated. To test the predictive validity, 2 structural equation models with binary outcome variables (change in smoking status) were estimated in experimenters (N = 798) and nondaily smokers (N = 506) separately.

RESULTS

Test-retest correlations of pleasant and unpleasant experiences were .63 and .66, respectively. Pleasant and unpleasant experiences predict the change of smoking status in the group of experimenters (odds ratio [OR] = 1.57 [1.00-2.48] and 0.58 [0.42-0.80], respectively), but these coefficients (OR = 1.53 [0.79-1.74] and 1.17 [0.82-2.83], respectively) did not reach the level of significance in nondaily smokers.

CONCLUSIONS

Self-reports of ESE demonstrate good short-term temporal stability. The early unpleasant smoking experience might have a different role in different stages of smoking acquisition.

Group-based trajectory modeling in clinical research

Group-based trajectory models are increasingly being applied in clinical research to map the developmental course of symptoms and assess heterogeneity in response to clinical interventions. In this review, we provide a nontechnical overview of group-based trajectory and growth mixture modeling alongside a sampling of how these models have been applied in clinical research. We discuss the challenges associated with the application of both types of group-based models and propose a set of preliminary guidelines for applied researchers to follow when reporting model results. Future directions in group-based modeling applications are discussed, including the use of trajectory models to facilitate causal inference when random assignment to treatment condition is not possible.

Nicotine dependence symptoms among recent onset adolescent smokers

The present study examined the prevalence of individual nicotine dependence symptoms among recent onset smokers across the continuum of nondaily and daily cigarette smoking behavior in a nationally representative sample of recent onset smokers from the National Surveys on Drug Use and Health (NSDUH). Rates of endorsement for 17 symptoms drawn primarily from the Nicotine Dependence Symptom Scale (Shiffman et al., 2004) were calculated for four levels of nondaily (smoked 1-3, 4-10, 11-20, or 21-29 days in the past 30 days) and daily (smoked 1, 2-5, 6-15, or >15 cigarettes per day in the past 30 days) smoking. Logistic and linear regression analyses with polynomial contrasts controlling for age, gender, length of exposure, and smoking quantity tested trends in symptom endorsement across levels of smoking. Significant linear and quadratic trends indicated that increasing rates of endorsement differed most between the lowest levels of nondaily and daily smoking. Results suggest that, for some, infrequent smoking may not represent benign experimentation. Recognizing early symptoms of nicotine dependence may assist in early identification and intervention of those at risk for heavier smoking in the future. Adolescents can be taught to recognize the early symptoms of nicotine dependence to increase awareness of the rapidity at which these symptoms may appear.

Sequencing of DSM-IV criteria of nicotine dependence

AIMS

To determine whether there is a sequence in which adolescents experience symptoms of nicotine dependence (ND) as per the DSM-IV.

DESIGN

A two-stage design was implemented to select a multi-ethnic target sample of adolescents from a school survey of 6th-10th graders from the Chicago Public Schools. The cohort was interviewed at home five times with structured computerized interviews at 6-month intervals over a 2-year period.

PARTICIPANTS

Subsample of new tobacco users (n = 353) who had started to use tobacco within 12 months prior to wave 1 or between waves 1 and 5. MEASUREMENTS AND STATISTICAL METHODS: Monthly histories of DSM-IV symptoms of ND were obtained. Log-linear quasi-independence models were estimated to identify the fit of different cumulative models of progression among the four most prevalent dependence criteria (tolerance, impaired control, withdrawal, unsuccessful attempts to quit), indexed by specific symptoms, by gender and race/ethnicity.

FINDINGS

Pathways varied slightly across groups. The proportions who could be classified in a progression pathway not by chance ranged from 50.7% to 68.8%. Overall, tolerance and impaired control appeared first and preceded withdrawal; impaired control preceded attempts to quit. For males, tolerance was experienced first, with withdrawal a minor path of entry; for females withdrawal was experienced last, tolerance and impaired control were experienced first. For African Americans, tolerance by itself was experienced first; for other groups an alternative path began with impaired control.

CONCLUSIONS

The prevalence and sequence of criteria of ND fit our understanding of the neuropharmacology of ND. The order among symptoms early in the process of dependence may differ from the severity order of symptoms among those who persist in smoking.

Constitutional mechanisms of vulnerability and resilience to nicotine dependence

The core nature of nicotine dependence is evident in wide variations in how individuals become and remain smokers. Individuals with pre-existing behavioral traits are more likely to develop nicotine dependence and experience difficulty when attempting to quit. Many molecular factors likely contribute to individual variations in the development of nicotine dependence and behavioral traits in complex manners. However, the identification of such molecules has been hampered by the phenotypic complexity of nicotine dependence and the complex ways molecules affect elements of nicotine dependence. We hypothesize that nicotine dependence is, in part, a result of interactions between nicotine and pre-existing behavioral traits. This perspective suggests that the identification of the molecular bases of such pre-existing behavioral traits will contribute to the development of effective methods for reducing smoking dependence and for helping smokers to quit.

Impulsiveness and cigarette smoking

OBJECTIVE

Varying aspects of impulsive personality have been associated with tobacco use in cross-sectional and prospective studies, including novelty seeking and (low) constraint but most studies have not examined more than one tobacco use phenotype (e.g., any tobacco use versus dependence) or considered more than one variety of impulsiveness simultaneously.

METHODS

The current study was conducted to evaluate the association of impulsive personality features with multiple tobacco use phenotypes including smoking status, lifetime tobacco consumption, and dependence in a sample of 1284 adults between the ages of 30 and 54. Participants completed multiple self-report measures of impulsive personality and were interviewed regarding lifetime tobacco use.

RESULTS

Results revealed that reward seeking and disinhibitory traits were both associated with smoking status but only disinhibition was associated with tobacco dependence, after controlling for reward seeking.

CONCLUSIONS

The results reported here may aid investigations aimed at identifying neurobiological, including genetic, correlates of tobacco use and dependence by providing potential behavioral correlates of the diversity of tobacco use phenotypes. Moreover, successful efforts to prevent tobacco-related disease through prevention or cessation programs will be facilitated by the identification of factors that are differentially associated with different smoking phenotypes.

Impact of a preventive intervention targeting childhood disruptive behavior problems on tobacco and alcohol initiation from age 10 to 13 years

The distal impact of a school based universal preventive intervention targeting disruptive behavior problems on tobacco and alcohol use from age 10 to 13 years was explored. Second grade classrooms (children aged 7 years) were randomly assigned to the intervention or a control condition. Tobacco and alcohol use from age 10 to 13 years was available for 477 children (72% of original sample). The impact of intervention on the initial level and growth in probability of substance use was explored. Results showed that intervention children had lower probabilities of tobacco use over the ages 10-13 years. This effect remains significant when controlling for (male) sex, pre-intervention levels of conduct problems, exposure to prenatal smoking or current parental smoking. For alcohol use, no effect of intervention during childhood was found. However, intervention children reported having a lower probability in alcohol use with age among those children reporting having used in the last week. The results underscore the importance of the early prevention of disruptive behavior problems substance use initiation. Implications for prevention and research are discussed.