Peer and parental influences on longitudinal trajectories of smoking among African Americans and Puerto Ricans.

The purpose of this study was to identify distinct trajectories of smoking behavior during a period extending from adolescence (mean age = 14 years) to young adulthood (mean age = 26 years) among African American and Puerto Rican adolescents/young adults, to examine ethnic and gender differences in group membership, and to assess the ability of peer and parental smoking to distinguish among trajectory groups. A community-based sample of 451 African American and Puerto Rican adolescents was interviewed four times during adolescence and in early adulthood, covering a span of 12 years. For both ethnic/racial groups, four distinct trajectories were identified: Nonsmokers, maturing-out smokers, late-starting smokers, and early-starting continuous smokers. Compared with Puerto Ricans, African Americans were over-represented in the nonsmoking group, whereas Puerto Ricans were over-represented in the early-starting continuous group. Females were more likely than males to be early-starting continuous smokers than late starters. Adolescents who were exposed to peer and parental smoking in early adolescence were more likely to belong to trajectory groups characterized by higher levels of smoking. These findings show that exposure to peer and parental smoking in early adolescence constitutes a risk factor for engaging in elevated levels of smoking behavior at an early age and for continued smoking into adulthood for urban African Americans and Puerto Ricans. To be most effective, smoking prevention programs should address peer group and family influences on adolescent smoking.     

Adolescent smoking trajectories and nicotine dependence.

The present study correlates empirically constructed prospective adolescent smoking trajectories with indicators of nicotine dependence assessed in adolescence and in adulthood. Excluding individuals who reported no smoking during repeat assessment (nonadopters), we identified five smoking trajectory groups: experimenters (n=116, 48.5%), late increasers (n=39, 16.3%), early increasers (n=37, 15.5%), quitters (n=22, 9.2%), and persistent smokers (n=25, 10.5%). Higher frequency of nicotine dependence symptoms in adolescence occurred in the quitters and persistent smokers groups, who smoked at higher levels relative to the experimenters, late increasers, and early increasers groups, who reported a similar frequency of nicotine dependence symptoms and smoked at low levels. Lifetime nicotine dependence was assessed in adulthood in lifetime daily smokers using the Fagerstr?m Test for Nicotine Dependence (FTND) and the Nicotine Dependence Scale (NDS). Lifetime FTND levels were similar across trajectory groups. Relative to experimenters, all remaining smoking trajectory groups had higher NDS levels that were similar to one another. These results suggest that higher levels of adolescent nicotine dependence were associated with heavier smoking trajectory groups, and that regardless of trajectory group membership, smoking more than a few cigarettes per week throughout adolescence resulted in similar levels of lifetime nicotine dependence as measured by the FTND and NDS.     

Adolescent to emerging adulthood smoking trajectories: when do smoking trajectories diverge, and do they predict early adulthood nicotine dependence?

This study evaluated the adolescent tobacco-use trajectories that predict nicotine dependence in early adulthood and when these trajectories start to diverge. As part of a follow-up to a large prevention trial, the present study evaluated 1,017 individuals from early adolescence (age 12) to early adulthood (age 28). Participants were recruited from eight middle schools in Kansas City, Missouri. Students were entering 6th grade or 7th grade at baseline. Smoking was evaluated at baseline, 6 months, at annual follow-ups through high school, and every 18 months thereafter until age 28. The study goals were to determine (a) whether distinct weekly tobacco-use trajectories could be identified between early adolescence and emerging adulthood (ages 12-24); (b) when during development these trajectories diverged; and (c) which trajectories could predict nicotine dependence in early adulthood (ages 26-28). A four-trajectory mixed model (abstainers, low users, late stable users, and early stable users) demonstrated the best fit to the data. Membership in increasingly high-use trajectories placed participants at greater relative risk for becoming nicotine dependent than did membership in lower-use trajectories. General linear models showed greater weekly cigarette consumption for early stable users as early as the first wave of data collection (age 12) and significant differences among all other trajectories by age 15. The findings support the implementation of smoking prevention programs early in middle or junior high school and suggest that adolescents who are already smoking at least two cigarettes per week by age 12 may benefit from additional addiction prevention efforts.     

The return to smoking: 1-year relapse trajectories among female smokers.

Research has demonstrated that a lapse in cigarette abstinence often leads smokers to fully relapse (i.e., return to daily smoking). However, patterns of smoking resumption beyond the point at which relapse occurs have not been examined in systematic follow-up studies. Daily cigarette intake data for 108 female adult smokers who participated in a smoking cessation trial were recorded at several points during the 365 days following the participants' quit date. SAS Proc Traj, a group-based mixture modeling procedure, was used to determine cigarette-use trajectories over time (i.e., patterns of smoking resumption). Over the 365 days, 27% of the sample maintained abstinence. Among the 73% who relapsed, four distinct trajectories emerged: low-level users (8% of the overall sample), moderate users (17%), slow-returners (15%), and quick-returners (33%). A few individual characteristics differentiated these groups. Overall, the findings illustrate that, after relapsing, smokers do not follow a unitary course of smoking resumption; rather, they exhibit more variable resumption patterns than previously assumed.     

Identifying and predicting adolescent smokers' developmental trajectories.

Very few studies have defined trajectories of smoking. In the present study, we modeled growth in adolescent smoking and empirically identified prototypical trajectories. We conceptualized escalation of smoking as a growth process and modeled rates of change and heterogeneity of these patterns using latent growth mixture modeling. The analysis identified six trajectories with low ambiguity about group membership (early rapid escalators, late rapid escalators, late moderate escalators, late slow escalators-smokers, stable puffers, and late slow escalators-puffers). A trajectory of quitters was not identified. We also examined predictors of the smoking trajectories. The predictors were assessed across the adolescent years and included variables related to smoking and other substance use, as well as a range of variables related to sociodemographic factors and mental health. Observed change in the pattern of predictors across age has implications for the mechanism of effect of these variables in relation to smoking trajectories, including predictors that differentiated among daily smokers, variables that may determine the trajectory (e.g., friends smoking), and variables that may result from the trajectory (e.g., marijuana use, less attachment to friends).     

A meta-analytic review of the CYP2A6 genotype and smoking behavior.

Individuals who carry variant alleles of the CYP2A6 gene are poor metabolizers of nicotine and are believed to be more sensitive to nicotine's aversive effects than those with normal alleles. This sensitivity is hypothesized to exert a protective effect against smoking initiation and lead to lower cigarette consumption among smokers with variant alleles. Although early studies found an association between variant CYP2A6 alleles and smoking behavior, more recent studies have not. A meta-analysis was conducted to help resolve these conflicting results. A literature search produced 11 studies providing information on CYP2A6 genotyping in smokers or nonsmoking control subjects. Participants were classified as smokers (ever-smokers or current smokers) or nonsmokers (former or never-smokers), and as carrying normal CYP2A6 genes or one or more variant alleles. Information regarding cigarette consumption also was included. Effect sizes were calculated from each study and then aggregated into an overall effect size. This analysis failed to find any empirical evidence of a relationship between variant CYP2A6 alleles and smoking status (n=4091) or cigarette consumption (n=1537). Although these results suggest the CYP2A6 gene is not associated with smoking behavior, the use of broad smoking status classifications (e.g., ever- vs. never-smoking), which fail to account for the complex nature of gene expression (e.g., gene-gene interactions), may have obscured the relatively modest genetic influences that might have been present. What role, if any, the CYP2A6 gene plays in smoking behavior will be understood only if future research addresses these methodological concerns.     

Reactivity to in vivo smoking cues in older adolescent cigarette smokers.

Most smokers initiate smoking in adolescence, and craving for cigarettes may play an important role in maintenance of smoking behavior and relapse to smoking during a quit attempt. Although a significant body of literature explores cue-reactivity in adult smokers, little has been published on cue-reactivity among adolescent smokers. In a previously published work, we found that videotaped smoking cues may not be robust in eliciting craving among adolescent smokers. Hence, in this preliminary study, we examined reactivity to in vivo smoking cues among adolescent smokers (N = 11, average age = 18.1 years, range = 15-19 years, predominantly female). Participants were presented with in vivo smoking and neutral cues (counterbalanced). We recorded subjective craving and real-time heart rate in response to each type of cue. Adolescent smokers had a significantly greater "desire" to smoke (p < .05) in response to smoking cues vs. both baseline and neutral cues. Participants had faster heart rates after the smoking cues during the epochs of 21-30 s and 31-40 s (p values<.05) as compared with baseline, and mean heart rate was higher during the smoking cues relative to neutral cues among participants who received the smoking cues first (p < .05). Results of this preliminary study further demonstrate the feasibility of conducting cue-reactivity studies with adolescent cigarette smokers. Findings from this study suggest that adolescent smokers may show patterns of responding to smoking cues similar to those of adult smokers. Implications for future laboratory studies with adolescent smokers are discussed.     

Associations between parental smoking restrictions and adolescent smoking.

The purpose of this study was to examine the cross-sectional relation between reported levels of parental smoking restriction and several behavioral and cognitive variables in a sample of 757 (363 males, 394 females) adolescent smokers. Experimenters administered surveys to students in the homerooms of three Florida high schools. After controlling for student age, gender, and parental smoking status, results revealed that more restrictive parental smoking policies were significantly associated with less smoking on weekdays and weekend days, greater latency to smoking the first cigarette of the day, greater motivation to quit smoking, greater confidence in ability to quit smoking, and higher estimated risk perception regarding the health consequences of smoking. Results also revealed that 44% of adolescent smokers reported that their parents or legal guardians did not know that they smoked tobacco. These findings suggest that parental smoking restrictions may have the potential to impede adolescent progression to adult smoking behavior by reducing smoking rates and nicotine dependence, and increasing motivation to quit, self-confidence to quit, and health risk perception. Parental restrictions on smoking may present obstacles and inconveniences to adolescent smoking behavior that make smoking cessation a more attractive option.     

Cigarette smoking patterns among young adults aged 18-24 years in the United States.

Most tobacco control programs focus on prevention for children or cessation for adults. Little is known about cigarette smoking among young adults. This study examined sociodemographic variables associated with current, daily, heavy, and light smoking among young adults in the United States. Data from the 1998-1999 Tobacco Use Supplement to the Current Population Survey (TUS-CPS) were used to examine cigarette smoking patterns and correlates of smoking among 15,371 young adults aged 18-24 years. We found that 26% of young adults were current smokers, 20% were daily smokers, and 8% were former smokers. Current smoking rates were higher among American Indians/Alaska Natives (33%) and Whites (31%) than among other racial/ethnic groups. Compared with white-collar workers, blue-collar and service workers were more likely to report current and daily smoking. Blue-collar workers also were more likely to report heavy smoking (OR = 1.97). The unemployed (those in the labor force but not currently working) and those reporting an annual household income of less than US$20,000 were more likely to report current, daily, and heavy smoking, compared with those not in the labor force and those reporting an annual household income of $20,000 or more, respectively. Young adults not currently enrolled in school were more than twice as likely to report current (OR = 2.36) and daily (OR = 2.90) smoking, compared with those currently enrolled in school. Differential cigarette smoking patterns by race/ethnicity, occupation, employment status, household income, and school enrollment status should be considered when developing interventions to reduce smoking among young adults.     

Smoking behaviour among young adults: beyond youth prevention

Objective: There is a widespread assumption that smoking behaviour is largely established by the age of 18 years. As a result, smoking prevention has focused almost exclusively upon youth. However, recent trends suggest that young adulthood may be an important—and largely overlooked—period in the development of regular smoking behaviour. The current study sought to examine patterns of tobacco use among young adults (aged 18–29 years) and to address the implications for tobacco control policy.

Design: Data are presented from the 2003 Canadian Tobacco Use Monitoring Survey, a national survey of smoking behaviour (n = 10 559, response rate 89%).

Main outcome measures: Measures of smoking behaviour, smoking initiation, susceptibility to smoking, and occupational status.

Results: A total of 1.4 million or 28% of young adults in Canada currently smoke, the highest proportion among all age groups. The prevalence of daily smoking rose from 8% among youth to 22% among young adults, and approximately one fifth of smokers tried their first cigarette after the age of 18 years. Smoking behaviour among young adults was also distinct from older smokers: young adults were more likely to be occasional smokers and reported lower daily consumption. Finally, smoking prevalence and cessation rates varied substantially within subgroups of young adults, as characterised by occupational setting.

Conclusions: Dramatic increases in the proportion and intensity of smoking occurs after the age of 18 years. Smoking behaviour among young adults is distinct from both youth and older adults, and warrants immediate attention from the public health community.

     

Comparison of cigarette and water pipe smoking among female university students in Egypt.

This study investigated behavioral and sociodemographic factors associated with tobacco use among female university students patronizing water pipe cafes in Cairo, Egypt. We interviewed two groups of female university student smokers (100 and 96 students from a public and a private university, respectively). The interviews took place in nine water pipe cafes near the two universities. A logistic regression model was developed to analyze the relationship between tobacco-related knowledge and beliefs and the choice between smoking water pipe or cigarettes. Among these smokers, 27% smoked cigarettes only, 37.8% smoked water pipe only, and 35.2% smoked both types of tobacco. Most of the water pipe smokers (74.1%) preferred this method because they believe it to be less harmful than smoking cigarettes. More than half of the subjects were encouraged to start smoking by other females (56.6%). Curiosity was a significant factor for initiation (OR = 2.8, 95% CI = 1.3-6.2, p<.01). We found no significant differences between water pipe and cigarette smokers regarding current age, age at initiation, quit attempts, knowledge about the hazards of smoking, wanting to be fashionable, or smoking with friends. About one in four (23.7%) attempted to quit, with health cited as a major reason. An urgent need exists for correction of the misperception among this study population that water pipe smoking is safe and less harmful than cigarette smoking.     

Cigarette and waterpipe smoking among Lebanese adolescents, a cross-sectional study, 2003-2004.

Waterpipe or "argileh" is a form of smoking other than cigarettes that is currently spreading among people of all ages. The objective of the present study was to assess tobacco smoking practices (waterpipe and/or cigarette) among public and private adolescent school students in Beirut, Lebanon. A sample of 2,443 students selected from 10 private and 3 public schools with intermediate/secondary classes filled out a self-administered anonymous questionnaire that inquired about sociodemographic characteristics, and behavior about tobacco smoking. Binary analysis was performed as well as three regression models for the relationship between exclusive cigarettes smoking, exclusive waterpipe smoking and both cigarettes and waterpipe as the dependent variables and gender, type of school, and class as the independent variables. The current prevalence of cigarettes smoking was 11.4%, and that of waterpipe smoking was 29.6%. Gender was significantly associated with cigarettes (OR=3.2, 95% CI 1.8-5.6) but not waterpipe smoking. Public school students were, respectively, 3.2 (95% CI 1.8-5.6) and 1.7 (95% CI 1.4-2.1) times more likely to be exclusive cigarettes smokers, and exclusive waterpipe smokers. Class was not significantly associated with exclusive cigarette smoking; however, students attending secondary classes were 1.3 (95% CI 1.1-1.6) times more likely to be exclusive waterpipe smokers. The reasons behind the high prevalence of both types of smoking are presented and discussed. The present study calls for school-based prevention programs and other types of interventions such as tax increases, and age-restrictions on tobacco sales. More aggressive interventions to disseminate education and awareness among parents and students altogether are warranted.     

Higher nicotine and carbon monoxide levels in menthol cigarette smokers with and without schizophrenia.

This study examined whether smoking menthol cigarettes was associated with increased biochemical measures of smoke intake. Expired carbon monoxide (CO) and serum nicotine and cotinine were measured in 89 smokers with schizophrenia and 53 control smokers immediately after smoking an afternoon cigarette. Serum nicotine levels (27 vs. 22 ng/ml, p = .010), serum cotinine levels (294 vs. 240 ng/ml, p = .041), and expired CO (25 vs. 21 ppm, p = .029) were higher in smokers of menthol compared with nonmenthol cigarettes, with no differences in 3-hydroxycotinine/cotinine ratios between groups when controlling for race. Backward stepwise linear regression models showed that, in addition to having a diagnosis of schizophrenia, smoking menthol cigarettes was a significant predictor of nicotine and cotinine levels. Individuals with schizophrenia or schizoaffective disorder smoked more generic or discount value brands (Basic, Doral, Monarch, USA, Wave, others) compared with control smokers (28% vs. 6%, p = .002) but did not smoke more brands with high nicotine delivery as estimated by the U.S. Federal Trade Commission method. Although rates of mentholated cigarette smoking were not higher in smokers with schizophrenia overall, they were significantly higher in non-Hispanic White people with schizophrenia compared with controls of the same ethnic/racial subgroup (51% vs. 28%, p<.0001). The higher exhaled CO in menthol smokers suggests that the higher nicotine levels are at least partly related to increased intake of smoke from menthol cigarettes, although menthol-mediated inhibition of nicotine metabolism also may be a factor. Menthol is an important cigarette additive that may help explain why some groups have lower quit rates and more smoking-caused disease.     

Affective decision-making deficits, linked to a dysfunctional ventromedial prefrontal cortex, revealed in 10th-grade Chinese adolescent smokers

This study addressed the question of whether poor decision making would be associated with adolescent past 7-day smoking. We conducted a cross-sectional study of 208 10th-grade adolescents in Chengdu City, China. We used the Iowa Gambling Task (IGT) to assess decision-making, and the Self-ordered Pointing Task (SOPT) to assess working memory capacity. Paper and pencil questionnaires assessed the school academic performance (SAP) and smoking variables. The results showed that a significantly higher proportion of past 7-day smokers (91.7%) were susceptible to future smoking and cigarette offers from best friends compared to other levels of smokers (never, ever and past 30-day smokers). Consistent with these behavioral data, the neuropsychological assessments revealed that relative to never smokers, past 7-day adolescent smokers (but not ever smokers or past 30-day smokers) demonstrated significantly lower scores on the IGT. Moreover, a higher proportion of past 7-day smokers (91.7%) performed poorly (no more than an overall net score of 10) on the IGT than nonsmokers and irregular (ever or past 30-day) smokers (about 65.3%). There were no differences on working memory performance for smokers (at any level) compared to never smokers after adjusting for school-type. In addition, logistic regression showed that the IGT significantly predicted past 7-day smoking after controlling for the working memory, school academic performance and demographic variables. These results suggest that poor affective decision making might predispose some adolescents to smoking in the future or in the social situations where their peers are smoking. Intervention targeting affective decision making might hold promise for reducing adolescents' risks for substance use.     

Real-time craving and mood assessments before and after smoking.

This study explored some quandaries concerning craving and mood as motivators to smoke. Craving and negative mood have long been associated with day-to-day smoking as two of the primary motivational forces behind the maintenance of the behavior, as well as significant barriers in smokers' attempts to quit. Craving remains a clinically relevant phenomenon, with most smokers describing craving as a troublesome problem when quitting. Smokers' self-reports of negative mood, as an antecedent for smoking, are so robustly reported that many models of nicotine dependence have incorporated a critical role for negative mood in maintaining smoking behavior. However, several naturalistic studies that collected mood ratings with hand held computers from smokers in real time, just before smoking a cigarette, have provided scant evidence that negative mood plays a major role in motivation to smoke. No study to date has examined craving and mood data as a consequence of smoking, that is, collecting the same data immediately after smoking. This study used personal digital assistants (PDAs) to collect craving and mood data immediately before smoking, immediately after smoking, and at random times of day. Nontreatment seeking smokers (N = 72) carried a PDA for an average of 10 days while they recorded their smoking behavior. Results showed that craving and negative mood ratings were lowest immediately after smoking compared with immediately before smoking and at random times of day. These findings suggest that smokers may be at least partially motivated to smoke to lower their craving and improve their mood states.     

The role of impulsivity on smoking maintenance.

In order to better understand why those higher in impulsivity experience more difficulties during smoking abstinence, the current study examined the possible mechanisms contributing to cigarette smoking relapse. Fifty dependent cigarette smokers completed measures designed to assess craving, tobacco withdrawal severity, and negative affect during 48 hours of nicotine abstinence. Using a series of multilevel models (SAS Proc Mixed Procedure), significant impulsivity x time analyses revealed differences in craving, F(2, 96) = 3.74, p<.05, and anxiety, F(2, 96) = 3.23, p<.05. Simple slopes analyses indicated that heightened trait-impulsivity predicted greater increases in craving and anxiety during a 48-hour abstinence period. These findings suggest that smokers with higher levels of impulsivity may lack the ability to find an accessible and comparable substitute for cigarette smoking during a cessation attempt. This study also highlights the importance of considering individual differences when treating those who wish to quit smoking.     

Early cigarette use and psychological distress as predictors of obesity risk in adulthood.

The study examined the simultaneous longitudinal relationships of cigarette use in adolescence to continuing cigarette use, psychological distress, physical activity, subjective rating of health in emerging adulthood and, finally, to body mass index (BMI) in early adulthood. The study utilized data (N=414) from a drug abuse prevention trial, Midwestern Prevention Project, with subjects participating from ages 11-34 years. Structural equation modeling showed that cigarette use in early adolescence had direct paths to distress in the beginning of emerging adulthood, which in turn had significant relationships to cigarette use, physical activity, and subjective rating of health in mid-emerging adulthood. Finally, both cigarette use and physical activity had significant negative relationships to BMI in early adulthood. Results suggest that prevention programs that have been previously applied to either cigarette use or distress prevention might be re-examined for their potential to also affect obesity risk in adulthood.     

Homelessness and smoking cessation: insights from focus groups.

Smoking prevalence among homeless persons is approximately 70%, yet little is known about tobacco use patterns or smoking cessation practices in this population. We assessed smoking attitudes and behaviors, psychosocial and environmental influences on smoking, barriers to and interest in quitting, and preferred methods for cessation among some homeless smokers. Six 90-min focus groups of current smokers (N = 62) were conducted at homeless service facilities. Participants had a mean age of 41.5 years (SD = 9.3), were predominantly male (69.4%) and African American (59%), and smoked an average of 18.3 cigarettes/day. Although most reported that they were motivated to quit, a number of barriers to quitting were identified. Participants reported that the pervasiveness and social acceptance of tobacco use in homeless settings contributed to smoking more cigarettes per day, adopting alternative smoking behaviors such as smoking cigarette butts and making their own cigarettes, and experiencing difficulty in quitting. High levels of boredom and stress also were cited as reasons for continued smoking. Smoking frequently occurred in combination with alcohol or illicit drug use or to achieve a substitute "high." Most participants (76%) reported that they planned to quit smoking in the next 6 months. Many were interested in using pharmacotherapy in combination with behavioral treatments. Results suggest that, although motivated to quit smoking, homeless smokers are faced with unique social and environmental barriers that make quitting more difficult. Interventions must be flexible and innovative to address the unique needs of homeless smokers. Smoking restrictions at homeless service facilities and funding for smoking cessation assistance in this underserved population may help to reduce prevalence.     

"Withdrawal symptoms" in adolescents: a comparison of former smokers and never-smokers.

Since the early 1980s, investigators have been reporting that adolescent smokers felt "dependent" on cigarettes and that adolescents trying to quit smoking experienced the same withdrawal symptoms observed in adult quitters, including restlessness, insomnia, increased appetite and weight gain, irritability or anger, depression, craving for cigarettes, and trouble concentrating. We hypothesized that most of these symptoms might be attributed to adolescence itself. To investigate this hypothesis, we examined the prevalence of these seven "adult" withdrawal symptoms in a population of adolescent former smokers and never-smokers. Participants were high school students in Houston, Texas, participating in a nested, group-randomized control group study designed to estimate the impact of a CD-ROM intervention for smoking prevention and cessation. We measured differences in symptoms frequency between never-smokers and former smokers, matched in a 2:1 ratio on sex and race/ethnicity, and differences in symptoms among former smokers as a function of time since final quit attempt and prior level of smoking. Only former heavy smokers have shown significantly higher prevalence of withdrawal symptoms compared with never-smokers. Of the seven symptoms assessed, only craving incrementally increased with the intensity of smoking. Overall the individual withdrawal symptoms did not effectively differentiate between 112 never-smokers and 34 former lighter smokers (persons who used to smoke less than "a few cigarettes on most days"). Withdrawal symptoms can reliably differentiate former heavy smokers from light smokers and never-smokers, among adolescents. Because most adolescents tend to be lighter smokers, future tobacco use and cessation studies should interpret adult withdrawal symptoms among adolescents with caution.