Assessment of nicotine dependence among adolescent and young adult smokers: A comparison of measures

Introduction

Tobacco use often starts in adolescence, yet assessment of dependence among adolescent smokers remains a challenge, particularly given the potential discord between self-reports of smoking behavior and actual use. We could find no prior study, among adolescents, that directly compares the association between objective biomarkers of tobacco exposure (e.g., cotinine) and multiple measures of dependence. This study examined the concurrent validity of two common dependence measures: the Fagerström Test for Nicotine Dependence (FTND) and the Hooked on Nicotine Checklist (HONC). We further examined the FTND by removing the one item on cigarettes smoked per day.

Methods

Based within a parent clinical trial for adolescent smoking cessation, eligible participants were 12–21 years old, smoking ≥ 5 cigarettes per day on average, and with urine cotinine > 100 ng/ml at baseline. Results are based on participants who completed each measure and who provided a urine cotinine sample at baseline (N = 73).

Results

Results showed that the FTND was associated with cotinine (p < 0.001; R² = 0.25), and that this relationship held true for the revised FTND as well (p < 0.001; R² = 0.18). However, the HONC was only marginally associated with cotinine (p = 0.06; R² = 0.09).

Discussion

Our results suggest that the FTND may be better associated with actual smoking behavior in adolescents as compared to the HONC. Pending replication, our data provide caution with regard to assessment of nicotine dependence at least among established adolescent smokers who have more entrenched smoking behavior.     

The loss of autonomy over smoking in relation to lifetime cigarette consumption

New Zealand youth who had smoked only one cigarette had diminished autonomy over smoking. We sought to examine this issue in a US sample and examine the early onset of DSM-IV nicotine dependence. A self-administered survey was completed by 367 adolescent smokers in Massachusetts. Diminished autonomy was measured with the Hooked on Nicotine Checklist. Diminished autonomy was present in 5.7% of youth after one cigarette, in 9% after 2, in 26% after 3–4, in 44% after 5–9, in 43% after 10–19, in 67% after 20–99, and in 96% after 100 or more. DSM-IV nicotine dependence was absent in youth who had not smoked 10 cigarettes but was present in 9% after 10–19 cigarettes, in 17% after 20–99, and in 58% after 100 or more. Our data confirm the New Zealand study by showing diminished autonomy among subjects who had smoked only 1 or 2 cigarettes. Diminished autonomy after one or two cigarettes, and DSM-IV nicotine dependence after 10–19, support the sensitization-homeostasis theory of nicotine addiction that the addiction process is initiated by the first few cigarettes.     

Cannabidiol reduces cigarette consumption in tobacco smokers: Preliminary findings

The role of the endocannabinoid system in nicotine addiction is being increasingly acknowledged. We conducted a pilot, randomised double blind placebo controlled study set out to assess the impact of the ad-hoc use of cannabidiol (CBD) in smokers who wished to stop smoking. 24 smokers were randomised to receive an inhaler of CBD (n = 12) or placebo (n = 12) for one week, they were instructed to use the inhaler when they felt the urge to smoke. Over the treatment week, placebo treated smokers showed no differences in number of cigarettes smoked. In contrast, those treated with CBD significantly reduced the number of cigarettes smoked by ~ 40% during treatment. Results also indicated some maintenance of this effect at follow-up. These preliminary data, combined with the strong preclinical rationale for use of this compound, suggest CBD to be a potential treatment for nicotine addiction that warrants further exploration.     

Effects of abstinence and smoking on information processing in adolescent smokers

RATIONALE: Although adolescent smokers appear to display some of the hallmark features of dependence, the biological and behavioral effects of smoking in this population are poorly understood. OBJECTIVES: This study aimed to define empirically the effects of abstinence and smoking in adolescent smokers, using indices validated in adult smokers. METHODS: Subjects were 16 young novice smokers (five male, 11 female), ages 14-18 years. A modified Stroop task measured the ability to inhibit attention to smoking-related cues; the classic Stroop task measured the ability to inhibit a pre-potent response (i.e. reading a word); a rapid information processing (RIP) task measured vigilance. RESULTS: Abstinence increased and smoking decreased the intrusiveness of smoking cues. Parallel effects were seen in commission errors on the RIP task. These effects were restricted to heavier smokers (>11 cigarettes/day). Subjective withdrawal effects predicted the intrusiveness of smoking words during abstinence. The number of cigarettes smoked per day predicted the beneficial effect of smoking on the classic as well as modified Stroop tasks. The physiological effects of abstinence and smoking predicted RIP performance. CONCLUSIONS: Abstinence impairs and smoking improves inhibitory information processing in young novice smokers in a manner similar to adult smokers. Daily frequency of smoking is a critical moderator of these effects.     

Determinants of puff duration in cigarette smokers: I

This research was undertaken to provide information about variables that might account for the decreases in puff duration that consistently occur as a whole cigarette is smoked. Cigarette smoking was investigated under conditions in which subjects smoked cigarettes which they could not see. In a series of three experiments, the length of the tobacco rod, the length of the cigarette holder, and the cigarette nicotine delivery were systematically manipulated. The results showed that puff duration correlates with the length of the tobacco rod, and that visual stimulus control, satiation, distance from the burning ember to the smoker's mouth, nicotine delivery, particulate build-up during smoking, and subjective acceptability of cigarette smoke do not contribute significantly to the control of puff duration.     

Tobacco dependence, restraint and time to the first cigarette of the day

The number of minutes it takes for a smoker to have the first cigarette of the day is discussed as a useful, subject-classifying variable. Other researchers have proposed that almost all smokers are dependent (on nicotine) and that those who behave as if they are not (e.g., by not smoking immediately in the morning) are actively restraining their cigarette intake. Study 1 shows that many smokers who delay their smoking are not so much restraining themselves from a desired cigarette as they are avoiding an especially noxious one; individual differences in urinary pH do not account for the sensitivity of some smokers to tobacco in the morning. Study 2 indicates that early smokers are more dependent on tobacco than are the later smokers, in that early smokers in a smoking-treatment program are less likely to be able to quit smoking.     

Favorite cigarette of the day in a random sample of women smokers

From a random digit dialing survey of American women, we assessed current smokers (n = 371). Respondents were 33.6 ± 7.6 years old, 49.6% married, and 87.6% White, with an FTND score of 3.9 ± 2.6. When asked “which cigarette of the day would be the most difficult for you to give up?” 30 women gave uncodable responses and 341 women provided answers subsequently coded into 5 categories: FIRST; 43.7%, MEAL; 29.3%, LAST; 13.8%, ROUTINE; 7.3%, and ENHANCE; 5.9%. Response groups differed significantly on age (p < .01), smoking rate (p < .001), time to first cigarette (p < .001), and self-rated health (p < .05). In post hoc analyses, FIRST were older, smoked more cigarettes/day, and smoked sooner after waking than at least one other group. LAST smoked the fewest cigarettes/day, and ENHANCE rated their health significantly better than did all other groups. The FTND is coded as 1 for “first” and 0 for any other response. Examining more closely the richness contained in that “other” category is a novel approach that may prove useful as a phenotyping tool.     

Impact of smoking abstinence on working memory neurocircuitry in adolescent daily tobacco smokers

Rationale Efficient function of neurocircuitry that supports working memory occurs within a narrow range of dopamine neurotransmission. Work in rodents has shown that exposure to nicotine during adolescence leads to nicotine withdrawal emergent alterations in cortical and subcortical dopamine neurotransmission. Objectives To test for evidence that the efficiency of neurocircuitry supporting working memory is altered during acute smoking abstinence in adolescent daily tobacco smokers. Materials and methods Fifty-five adolescent daily tobacco smokers were compared with 38 nonsmokers using functional magnetic resonance imaging while subjects performed a verbal working memory task. Smokers were studied during smoking and after 24 h of abstinence from tobacco use. Results Performance of a task with high working memory load in the context of smoking abstinence was associated with greater activation of components of the verbal working memory neurocircuit, including left ventrolateral prefrontal cortex and left inferior parietal lobe, among smokers relative to nonsmokers. During smoking abstinence, smokers failed to exhibit increases in functional connectivity between components of the working memory neurocircuit with increasing working memory load observed in nonsmoking adolescents and in prior studies of adults. Conclusions Smoking abstinence in adolescent smokers is associated with reductions in the efficiency of working memory neurocircuitry and alterations in the functional coordination between components of the working memory neurocircuit. These alterations may stem from effects of nicotine exposure on catecholaminergic systems during adolescent development. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

A systematic review of the International Classification of Diseases criteria for the diagnosis of tobacco dependence

Our objective was to examine the evidence concerning the validity and reliability of the International Classification of Diseases criteria for tobacco dependence (ICD-TD). A literature search was conducted of 16 databases using the search terms addiction, cigarettes, Diagnostic and Statistical Manual of Disease, DSM, dependence, International Classification of Diseases, ICD, nicotine, smoking and tobacco. The search produced 37 relevant articles. We found no data supporting the predictive validity of the criteria, and none supporting the characterization of dependence as having a three-symptom threshold. We found no data concerning the validity or reliability of the official instrument, which inappropriately excludes nondaily smokers from being evaluated for dependence. We found no evidence that the ICD-TD diagnosis had been used for clinical decision making, in a smoking cessation study, or for longitudinal epidemiological surveillance. We contrast the utility of the ICD-TD criteria to an approach of diagnosing tobacco addiction on the basis of a single criterion of a compulsion to use tobacco.     

Latent factor structure of a behavioral economic cigarette demand curve in adolescent smokers

Behavioral economic demand curves, or quantitative representations of drug consumption across a range of prices, have been used to assess motivation for a variety of drugs. Such curves generate multiple measures of drug demand that are associated with cigarette consumption and nicotine dependence. However, little is known about the relationships among these facets of demand. The aim of the study was to quantify these relationships in adolescent smokers by using exploratory factor analysis to examine the underlying structure of the facets of nicotine incentive value generated from a demand curve measure. Participants were 138 adolescent smokers who completed a hypothetical cigarette purchase task, which assessed estimated cigarette consumption at escalating levels of price/cigarette. Demand curves and five facets of demand were generated from the measure: Elasticity (i.e., 1/α or proportionate price sensitivity); Intensity (i.e., consumption at zero price); O(max) (i.e., maximum financial expenditure on cigarettes); P(max) (i.e., price at which expenditure is maximized); and Breakpoint (i.e., the price that suppresses consumption to zero). Principal components analysis was used to examine the latent structure among the variables. The results revealed a two-factor solution, which were interpreted as "Persistence," reflecting insensitivity to escalating price, and "Amplitude," reflecting the absolute levels of consumption and price. These findings suggest a two factor structure of nicotine incentive value as measured via a demand curve. If supported, these findings have implications for understanding the relationships among individual demand indices in future behavioral economic studies and may further contribute to understanding of the nature of cigarette reinforcement.     

Depressed mood and the effect of two universal first grade preventive interventions on survival to the first tobacco cigarette smoked among urban youth

Introduction

As part of an evaluation of two first-grade, universal preventive interventions whose proximal targets were early learning and behavior, we investigated the influence of depressed mood, the interventions, and their interaction on survival to the first tobacco cigarette smoked through age 19. One intervention focused on improving teacher behavior management and instructional skills (Classroom-Centered, CC) as a means of improving student behavior and learning and the other on the family–school partnership (FSP). Variation in the relationship between depressed mood and first cigarette smoked by gender and grade was also examined.

Methods

Self-reports of smoking behavior and depressed mood were collected on an annual basis from grade 6 through age 19. The present analyses were restricted to the 563 youth who had never smoked by grade 6, or 83% of the original sample of first grade participants. Discrete-time survival analysis was used to examine the effects of depressed mood and the interventions on survival to the first tobacco cigarette smoked.

Results

Depressed mood was associated with reduced survival time to the first cigarette smoked (adjusted hazard ratio, aHR: 1.4; 95% CI: 1.1–1.9), whereas the CC intervention prolonged survival time (aHR: 0.8; 95% CI: 0.7–0.9). No significant variation in the effect of depressed mood on survival was found by gender or grade, nor was the effect of the CC intervention moderated by depressed mood.

Conclusions

Strategies to prevent tobacco cigarette smoking should include both a focus on depressed mood in adolescence as well as on early success in elementary school.     

Nicotine serves as an effective reinforcer of intravenous drug-taking behavior in human cigarette smokers

Rationale Although numerous studies have documented that nicotine can function as an effective reinforcer of intravenous self-administration behavior in animals, it has not been clearly shown to maintain intravenous self-administration behavior above vehicle placebo levels in humans.Objectives To compare the reinforcing effectiveness of nicotine versus saline placebo in human research volunteers responding under fixed-ratio (FR) schedules of intravenous drug self-administration while systematically increasing response requirements.Methods Eight male cigarette smokers resided in an inpatient research unit. During 3-h sessions, intravenous injections of nicotine and saline were available concurrently and were contingent on responding (pulling a lever). Nicotine dose (0.75, 1.5, 3.0 mg/injection), time out (TO) value after each injection (1–20 min) and FR response requirement (10–1600) were varied in different subjects over consecutive sessions.Results Number of nicotine injections/session significantly decreased as dose/injection increased and the number of self-administered nicotine injections was significantly greater than the number of self-administered saline injections across conditions. When FR value was progressively increased over sessions, response rates for nicotine, but not saline, injections increased, with maximal rates at the highest FR values. Rates of responding and injections/session were markedly and significantly higher for nicotine than for saline at FR values of 200 and above. Subjects rated effects of nicotine as both significantly more positive and more negative than saline placebo, with positive ratings significantly higher than negative ratings.Conclusions Nicotine functioned as a prototypic drug of abuse, serving as an effective reinforcer of intravenous drug-taking behavior in human cigarette smokers. Subjects adjusted their responding to response requirements in a way that maintained relatively constant levels of nicotine injections per session.Abstracts of these experiments previously appeared in Pharmacologist 25:219, 1983, and Neurosci Lett 14(Suppl):140, 1983.     

Reactivity to smoking cues in adolescent cigarette smokers

This study examined reactivity to smoking cues in adolescent smokers (n=12) and nonsmokers (n=32), between 14 and 19 years of age. Participants were presented with videotaped smoking and neutral cues in a counterbalanced order. Subjective and physiological responses to each cue type were obtained. Findings indicated that smokers reported greater desire to smoke cigarettes in response to smoking cues, relative to neutral cues, when the smoking cues were presented first. Smokers also reported greater dominance (i.e., sense of control) during smoking-cue presentations, but only when these cues were presented second. Finally, smokers' heart rate was faster during the initial portion of the smoking-related video, relative to the neutral cue. Overall, this study demonstrates the feasibility of conducting laboratory-based cue-reactivity studies with adolescent smokers. Findings suggest that adolescents smokers show similar patterns of responding to smoking cues as adult smokers, although effects were not particularly robust in this sample and subjective effects were dependent on cue order.     

Dependence on the nicotine gum in former smokers

We conducted an Internet survey in 2004–2007 in 526 daily users of the nicotine gum, to assess use of, and dependence on the nicotine gum in former smokers. We used modified versions of the Nicotine Dependence Syndrome Scale (NDSS-G), the Cigarette Dependence Scale (CDS-G) and the Fagerström Test (FTND-G). After 30 days, 155 participants (29%) indicated their gum use. Higher dependence on the gum predicted a lower chance of stopping using it at follow-up (odds ratio = 0.36 for each standard deviation unit on CDS-G, p = 0.001). More long-term (> 3 months) than short-term (< = 3 months) users of the gum agreed with: “I use the nicotine gum because I am addicted to it” (83% vs. 7%, p < .001), and fewer long-term users reported that they used the gum to avoid relapsing to smoking (42% vs. 92%, p < .001). Long-term users had higher ratings of dependence on the gum than short-term users, as assessed with NDSS-Gum, CDS-Gum and FTND-Gum (all p < .001). Most long-term users reported symptoms of dependence on the nicotine gum. Lower levels of dependence on the gum predicted cessation of gum use. However, long term use of the nicotine gum has no known serious adverse consequence, and may be beneficial if it prevents late relapse.     

Nicotine effects on affective response in depression-prone smokers

Rationale Comorbidity between cigarette smoking and depression is thought to arise because depression-prone smokers self-administer nicotine to improve mood. Yet little evidence supports this view, and nicotine’s effect on positive affect deficiency in depression remains largely unstudied. Objectives We hypothesized that (1) nicotine would dispel negative affect and enhance positive affect and (2) effects would be stronger for smokers vulnerable to depression, particularly during a depressed state. Materials and methods Regular smokers (N = 165) were recruited from the community: 63 with no history of major depressive disorder (MDD), 61 with recurrent past but no current MDD, and 41 with both current and past MDD. During four sessions, participants smoked either a nicotinized (NIC+) or denicotinized (NIC−) cigarette double blind after experiencing a negative mood induction or while undergoing a positive mood induction. Positive and negative affects were measured at baseline and at two time points after smoking. Results Previously depressed smokers showed a heightened positive mood response to positive mood induction when smoking a nicotinized cigarette. Nicotine also increased the degree to which positive mood induction dispelled negative mood in depression-vulnerable smokers. Finally, nicotine worsened the negative affect response to negative mood induction for all groups. Conclusion Self-administering nicotine appears to improve depression-prone smokers’ emotional response to a pleasant stimulus.     

The relationship between level of cigarette consumption and latency to the onset of retrospectively reported withdrawal symptoms

Rationale Subthreshold smokers (who smoke ≤5 cigarettes/day) experience withdrawal symptoms, yet they smoke less than is required to maintain serum nicotine levels.Objectives For study 1, our aim was to determine (1) if adult subthreshold smokers report withdrawal symptoms; (2) how they rate symptom severity; (3) the length of their latency to withdrawal symptoms; (4) and the relationship between level of cigarette consumption and latency to withdrawal. The aim of study 2 was to attempt to replicate the results of study 1 in a nationally representative sample and to compare subthreshold and threshold (≥6 cigarettes/day) smokers.Methods Study 1 was conducted through telephone interviews. Study 2 was conducted through secondary analysis of data from the National Youth Tobacco Survey (self-administered in schools).Results In study 1, all subjects experienced withdrawal symptoms. The mean number of symptoms was 4.3; mean intensity of each symptom was >6 (1–10 scale). A quarter of the subjects could go for ≥2 days before experiencing withdrawal. More frequent smokers had a shorter latency to withdrawal (r=−0.43, p<0.001, n=36). In study 2, 63% of subthreshold smokers reported feeling at least one withdrawal symptom. Median latency to withdrawal was 168 h for subthreshold and 2 h for threshold smokers. A negative correlation between level of cigarette consumption and latency to withdrawal was observed for both groups.Conclusions Although subthreshold smokers experience significant withdrawal symptoms, they can smoke infrequently because symptoms may not appear for one to several days. Consistent with the sensitization–homeostasis theory, low doses of nicotine can suppress withdrawal symptoms over long periods.     

The effect of cigarette burn time on exposure to nicotine and carbon monoxide in adult smokers

Cigarette burn time (CBT), conventionally defined as the time a cigarette burns during smoking, can be affected by cigarette design and smoking behavior. A previous study showed a strong negative correlation between CBT and nicotine yield under machine smoking conditions. This study for the first time examined the relationship of CBT and exposure to nicotine and carbon monoxide in adult smokers in a controlled clinical study. 24h nicotine equivalents excretion (NE), carboxyhemoglobin (COHb) and CBT were measured in two groups of 20 adults smoking Marlboro Lights and 20 adults smoking Marlboro Ultra on two consecutive days. Approximately 20% of the total variability in CBT was attributed to cigarette brand, 34% to smokers and 1% to study day. The exposure index, defined as the number of cigarettes smoked per day divided by average daily CBT for each smoker, accounted for a large proportion of the total variability in NE (R(2)=0.79-0.91) and COHb (R(2)=0.85-0.90). We conclude that CBT has an important influence on levels of NE and COHb in adult smokers. CBT, along with the number of cigarettes smoked per day, can be used to estimate adult smokers' exposure to nicotine and carbon monoxide.     

Gender and weight concerns in adolescent smokers

The aim of this study was to examine smoking-specific weight concerns in a well-characterized sample of adolescent daily smokers and the influence of gender, age, and body mass index (BMI). Adolescent smokers (n = 103) were asked two smoking-specific weight concern questions: “How much do cigarettes help you control your weight?” and “How concerned are you about gaining weight as a result of quitting?” A significant positive relationship was found between average daily cigarette use and belief in smoking as a means to control weight and a significant negative relationship between the years of smoking and belief that smoking controls weight. There was no significant relationship between BMI and smoking to control weight for females, whereas for males, there was a positive relationship, indicating that heavier males were more likely to report smoking to control weight. Additionally, females who smoked more cigarettes reported more concern about gaining weight upon quitting, a pattern not seen in males. Results highlight potentially important gender differences in the relationship between weight concerns and smoking and the influence these concerns may have on quitting smoking.     

Bupropion SR and contingency management for adolescent smoking cessation

There is a significant need for evidence-based treatments for adolescent smoking cessation. Prior research, although limited, has suggested potential roles for bupropion sustained-release (SR) and contingency management (CM), but no previous studies have assessed their combined effect. In a double-blind, placebo-controlled design, 134 adolescent smokers were randomized to receive a 6-week course of bupropion SR + CM, bupropion SR + non-CM, placebo + CM, or placebo + non-CM, with final follow-up at 12 weeks. The primary outcome was 7-day cotinine-verified point prevalence abstinence, allowing for a 2-week grace period. Combined bupropion SR + CM treatment yielded significantly superior abstinence rates during active treatment when compared with placebo + non-CM treatment. In addition, combined treatment showed greater efficacy at multiple time points than did either bupropion SR + non-CM or placebo + CM treatment. Combined bupropion SR and CM appears efficacious, at least in the short-term, for adolescent smoking cessation and may be superior to either intervention alone.