Physiological sensations of initial smoking in the development of regular smoking behavior

Reactions to reduced nicotine content cigarettes in a sample of young adult, low-frequency smokers

RATIONALE

Reducing nicotine content in cigarettes to ≤ 2.4 mg per g of tobacco [mg/g] reduces smoking behavior and toxicant exposure among adult daily smokers. However, cigarettes with similar nicotine content could support continued experimentation and smoking progression among young adults who smoke infrequently.

OBJECTIVES

This study evaluated the threshold for nicotine in cigarettes that produces reactions associated with smoking progression in a sample of young adults who smoke infrequently.

METHODS

Young adults (n = 87, 18-25 years, 49% female) using tobacco products ≤ 15 days per month completed three counterbalanced, double-blinded sessions, each measuring positive and negative subjective reactions to fixed doses of smoke from investigational cigarettes containing one of three different nicotine contents: normal (NNC; 15.8 mg/g); very low (VLNC; 0.4 mg/g); and intermediate (INC; 2.4 mg/g). In a final session, participants chose one of the cigarettes to self-administer.

RESULTS

Post-cigarette breath carbon monoxide was greater for VLNC than for NNC (p < 0.001). Positive reactions were greater for NNC than INC (p < 0.001) and for INC than VLNC (p = 0.001). Negative reactions were greater for NNC than INC and VLNC (both p < 0.001); INC and VLNC did not differ. Cigarette choices did not differ from an even distribution (43% NNC, 25% INC, 32% VLNC), but choice for NNC or INC was associated with higher ratio of positive to negative reactions during the NNC and INC fixed dose sessions, respectively (p < 0.001).

CONCLUSIONS

Reducing nicotine content will likely lower the abuse liability of cigarettes for most young, low-frequency smokers. Additional work is needed to determine if compensatory smoking may lead to increased toxicant exposure, and if a subset of individuals choosing lower nicotine cigarettes may continue to smoke regardless of nicotine content.

Factors Associated with the Initial Sensations of Smoking among Smokers with Mental Illness

People with mental illnesses (MI) have a disproportionate smoking prevalence and associated disease burden. Smoking initiation among people with MI is poorly understood. However, the sensations experienced during smoking initiation predict continued smoking and nicotine dependence. Yet, few studies have examined the initial experiences of smoking among people with MI. Thus, the aim of this study was to explore factors associated with the initial sensations of smoking in people with MI. Smokers in an inpatient psychiatric facility (n = 123) were surveyed. Data obtained included information on demographics, smoking and secondhand smoke (SHS) exposure, psychiatric diagnoses, and sensations of initial smoking. Spearman correlations explored associations among initial smoking sensation variables; and binary logistic regression analyses examined the associations between study variables and groupings derived from initial sensations (i.e., "pleasant + buzz," "unpleasant + buzz," and "all" sensations). The most frequently reported initial smoking sensation was feeling dizzy (87%) and there were low to moderate correlations between unpleasant (e.g., cough, sick, nervous) and pleasant (e.g., good, relaxed) sensations. In logistic regression analyses, having higher perceived SHS exposure was significantly associated with the "pleasant + buzz" sensation grouping; and lower past week SHS exposure was associated with the "unpleasant + buzz" sensation grouping; but, no variables were associated with "all" sensation group. Initial smoking sensations are an uncharted avenue of exploration in understanding smoking initiation among people with MI. SHS exposure may be an important factor associated with the report of both unpleasant and pleasant initial sensations. Future studies are needed to further explore initial sensations in relation to the context of smoking initiation among people with MI.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Using MIMIC models to examine the relationship between current smoking and early smoking experiences

INTRODUCTION

The present study expands previous research on early experiences with tobacco by using a Multiple Indicator Multiple Causes (MIMIC) model, which permits combining indicators tapping into pleasant experiences into one latent construct and those indicators of unpleasant experiences into another latent construct.

METHODS

A sample of 458 participants was recruited via newspaper advertisements. Response to early experimentation with cigarettes was assessed using the Early Smoking Experiences questionnaire, in which participants were asked the following question: "The first time you tried cigarettes, did you experience any of the following? (pleasurable and displeasurable sensations [overall], pleasurable rush or buzz, dizziness, relaxation, nausea, cough, difficulty inhaling)." These experiences were rated on a scale ranging from 1 = none to 4 = intense.

RESULTS

The MIMIC model revealed that current smoking status and age of initial experimentation with cigarettes were significantly associated with both early pleasant and unpleasant experiences (p < .05). African Americans were less likely than Whites to have early unpleasant experiences (p < .05). No association was found between race and early pleasant experiences.

DISCUSSION

Our findings are consistent with the inferences that pleasant experiences in response to early experimentation with smoking lead to regular smoking and that positive experiences play a stronger role than negative experiences in the transition to regular smoking. Our study also demonstrates that the MIMIC model is pertinent and practicable in nicotine and smoking research. We recommend it as a useful tool for identifying endophenotypes related to nicotine dependence and tobacco use latent constructs.

Perceptions of smoking and nonsmoking peers: the value of smoker and nonsmoker prototypes in predicting smoking onset and regular smoking among adolescents

Adolescents' perceptions of persons their age who smoke cigarettes (also known as prototypes of smoking peers) play a critical role in an adolescent's decision to start smoking. However, adolescents' perceptions of their peers who do not smoke (prototypes of nonsmoking peers) could be implicated in adolescents' smoking decisions as well. In the present study, the authors examined the additional role of nonsmoker prototypes in adolescents' smoking onset and regular smoking. At seven high schools, Dutch students (n = 1,035) between the ages of 12 and 15 years who were attending the eighth grade provided self-reported data on their smoker and nonsmoker prototypes and smoking behavior during a baseline and 6-month follow-up measurement. Logistic regression analyses showed that both smoker and nonsmoker prototypes assessed at Time 1 predicted smoking onset by Time 2 among nonsmoking adolescents. However, only nonsmoker prototypes predicted regular smoking among adolescents who smoked occasionally at baseline.

Validation of retrospective reports of early experiences with smoking

Initial sensitivity to the pharmacological effects of a drug may affect patterns of future use and dependence for a wide variety of drugs. Retrospective reports of sensations experienced upon early experimentation, however, may be limited by recall bias based on time elapsed and subsequent experiences. To validate reports of early experiences with nicotine, we studied 34 smokers who had contributed retrospective data on early experiences with smoking. Half had reported experiencing a buzz from smoking their first cigarette (the "yes" group), the other half had not (the "no" group). To simulate initial sensitivity to nicotine, we asked participants to remain abstinent from smoking for 5 days to allow for the dissipation of tolerance. They then participated in a laboratory session in which they were reexposed to nicotine in an unfamiliar form (nicotine nasal spray) and asked to indicate pleasurable responses by depressing a foot pedal if and when they experienced a "pleasurable buzz." Smokers in the "yes" group were marginally more likely to be male. The two groups did not differ significantly on age or race. The "yes" group smoked significantly more cigarettes/day than the "no" group. When the two groups were compared for response to nasal spray following 5 days' abstinence, smokers in the "yes" group were marginally more likely to have signaled experiencing at least one pleasurable buzz and rated "pleasurable sensation from spray" on a 100-mm visual analogue scale administered 10 min after nicotine dosing significantly higher than were those in the "no" group. To the extent that several days' abstinence can serve as a model for initial sensitivity to nicotine, our findings validate retrospective reports of pleasurable sensations upon early smoking experimentation.

Rapid progression to regular cigarette smoking among nonsmoking adolescents: interactions with gender and ethnicity

BACKGROUND

While the correlates and predictors associated with transition through the stages of smoking acquisition have received substantial attention, the identification of factors associated with the time course of progression remain generally unexplored.

METHODS

We identified adolescents escalating from nonsmoking to regular smoking in 1 year as rapid progressors (n = 98) and those escalating from nonsmoking to experimental smoking in 1 year as slow progressors (n = 555). We entered demographic and psychosocial variables, initial reactions to smoking variables, and their interactions with gender and ethnicity into a logistic regression analysis comparing rapid progressors to slow progressors.

RESULTS

At baseline, rapid progressors reported more friends who smoked regularly. Girls who reported more concern with dieting and less social success were more likely to progress to regular smoking within 1 year; these variables did not influence progression in boys. Those who associated positive feelings with their initial smoking experience were more likely to progress to regular smoking. Differences between white and African American youth emphasize the importance of physiological interpretations of initial smoking experiences.

CONCLUSIONS

Our findings suggest that even as nonsmokers, adolescents likely to progress quickly to regular smoking can be identified. Researchers designing prevention programs should take these factors into account.

Effects of an implicit mood prime on the accessibility of smoking expectancies in college women

This study examined whether an implicit mood prime would differentially affect the accessibility of self-generated smoking expectancies in women. One hundred nine ever-smokers were randomly assigned to receive either a positive or negative musical mood induction or a no-music control condition. Participants self-generated smoking expectancies, and the 1st responses were categorized as positive reinforcement, negative reinforcement, or negative consequence expectancies. Overall, participants generated mood-congruent smoking expectancies, suggesting that affect may act as a conditioned stimulus that elicits expectations of positive and negative reinforcement of smoking behavior. In addition, negative reinforcement expectancies were more frequently generated in current versus past smokers. Results are consistent with a situational-specificity hypothesis and memory-based models of affect and expectancies.

Taking a first puff: cigarette smoking experiences among ethnically diverse adolescents

OBJECTIVES

To study the social contexts and physiological consequences of an initial cigarette smoking experience among adolescents from four ethnic groups (African American, European American, Hispanic, Native American) who vary by gender and locale (e.g. urban vs rural).

METHOD

A qualitative study using individual interviews and focus groups.

RESULTS

Results both amplify and reinforce conclusions about peer and family influences on adolescent smoking initiation reported in quantitative studies of teen smoking. Within the broader themes of peers and family, several important sub-themes emerged. The study findings suggest that peer influence can be characterized as social conformity or social acceptance. Males were more likely than females to describe experiences involving peers exerting strong messages to conform to smoking behaviors. Roles played by family members in the initiation process were complex and included those of initiator, prompter, accomplice, and inadvertent source of cigarettes. European American and Hispanic girls provided descriptions of parents/family members as instigators of their first smoking experience. Hispanic adolescents descripted instances in which family members prompted cigarette use at a young age by encouraging the young person to light the adult's cigarette. Finally, ethnic differences in the physiological responses to initial smoking suggest the need to further explore the role of brand preference and variations in inhaling among ethnically diverse adolescents.

CONCLUSION

In order to design effective cigarette smoking prevention programs for adolescents, it is important to understand the meaning of smoking behaviors for adolescents from different ethnic and social backgrounds.

One-year predictors of smoking initiation and of continued smoking among elementary schoolchildren in multiethnic, low-income, inner-city neighbourhoods

OBJECTIVE

To identify one-year predictors of smoking initiation among never-smokers, and of continued smoking among ever-smokers.

DESIGN

Two sequential cohorts of grade 4 and 5 children. Data were collected as part of Coeur en sante St Louis du Parc, a non-randomised controlled trial to evaluate the impact of a school-based heart health promotion programme.

SETTING

24 inner-city elementary schools located in multiethnic, low-income neighbourhoods in Montreal.

SUBJECT

1824 schoolchildren aged 9-12 years with baseline and one-year follow-up data.

MAIN OUTCOME MEASURES

Changes in smoking behaviour over a year; the ability of baseline data to predict smoking initiation and continued smoking a year later was investigated in logistic regression analyses.

RESULTS

The prevalence of ever-smoking was 21.1% at baseline and 30.2% at one-year follow up. One in six never-smokers initiated smoking; one in three ever-smokers continued smoking. Predictors of initiation included age (odds ratio (OR) = 1.6, 95% confidence interval (CI) = 1.3 to 2.0), male gender (OR = 1.5 (95% CI = 1.1 to 2.0)), friends who smoke (OR = 2.3 (95% CI = 1.7 to 3.3)), sibling(s) who smoke (OR = 1.9 (95% CI = 1.2 to 3.1)), father/mother who smokes (OR = 2.2 (95% CI = 1.6 to 3.0)), and frequent high fat/"junk food" consumption (OR = 1.6 (95% CI = 1.1 to 2.1)). Age and friends who smoke were also independent predictors of continued smoking in both genders. In addition, in boys, current smokers at baseline were 2.6 times (95% CI = 1.4 to 5.0) more likely to continue smoking than past smokers. In girls, being overweight was associated with continued smoking (OR = 3.5 (95% CI = 1.6 to 7.6)).

CONCLUSIONS

Smoking prevention programmes should address parental and sibling influences on smoking, in addition to refusal skills training. Among girls, weight-related issues may also be important.