A sensitization–homeostasis model of nicotine craving, withdrawal, and tolerance: Integrating the clinical and basic science literature

Does the time to nicotine dependence vary by internalizing symptoms for young people who use e-cigarettes? An analysis of the Population Assessment of Tobacco and Health (PATH) study, (Waves 1-5; 2013-2019)

OBJECTIVE

To determine the relationship between past-year internalizing symptoms and the time to first report of signs of nicotine dependence among young people.

METHODS

Secondary analysis using data from the Population Assessment of Tobacco and Health (PATH) (Waves 1-5; 2013-2019). The study included 2,102 (N = 5,031,691) young people (age 12-23 years) who reported past-30-day (P30D) e-cigarette use in one or more waves. Kaplan Meier curves, stratified by past year internalizing symptoms were used to estimate the time to the first report of three nicotine dependence symptoms (i.e., use within 30 min of waking, cravings, and really needing to use) following the first P30D e-cigarette use. Cox proportional hazard models were used to estimate crude and adjusted hazard ratios (AHR), comparing any past year internalizing symptoms to no past year internalizing symptoms.

RESULTS

We found no significant differences between past year internalizing symptoms and the time to the first report of cravings (AHR = 1.30, 95 % CI = 92-1.85), really needing to use (AHR = 1.31; 95 % CI = 0.92-1.89) and use within 30 min of waking for follow-up times 0-156 weeks (AHR = 0.84; 95 % CI = 0.55-1.30) and > 156 weeks (AHR = 0.41; 95 % CI = 0.04-4.67) respectively.

CONCLUSION

Past year internalizing symptoms did not modify the time to the first report of nicotine dependence among youth with P30D e-cigarette use. Further research is needed to understand how changing internalizing symptoms and e-cigarette use frequency influence nicotine dependence over time and, how this relationship impacts cessation behavior.

Mifepristone decreases nicotine intake in dependent and non-dependent adult rats

BACKGROUND

Addiction to tobacco and nicotine products has adverse health effects and afflicts more than a billion people worldwide. Therefore, there is an urgent need for new treatments to reduce tobacco and nicotine use. Glucocorticoid receptor blockade shows promise as a novel treatment for drug abuse and stress-related disorders.

AIM

These studies aim to investigate whether glucocorticoid receptor blockade with mifepristone diminishes the reinforcing properties of nicotine in rats with intermittent or daily long access to nicotine.

METHODS

The rats self-administered 0.06 mg/kg/inf of nicotine for 6 h per day, with either intermittent or daily access for 4 weeks before treatment with mifepristone. Daily nicotine self-administration models regular smoking, while intermittent nicotine self-administration models occasional smoking. To determine whether the rats were dependent, they were treated with the nicotinic acetylcholine receptor antagonist mecamylamine, and somatic signs were recorded.

RESULTS

The rats with intermittent access to nicotine had a higher level of nicotine intake per session than those with daily access but only the rats with daily access to nicotine showed signs of physical dependence. Furthermore, mecamylamine increased nicotine intake during the first hour of access in rats with daily access but not in those with intermittent access. Mifepristone decreased total nicotine intake in rats with intermittent and daily access to nicotine. Moreover, mifepristone decreased the distance traveled and rearing in the open field test and operant responding for food pellets.

CONCLUSION

These findings indicate that mifepristone decreases nicotine intake but this effect may be partially attributed to the sedative effects of mifepristone.

CHRNA5-A3-B4 and DRD2 Genes and Smoking Cessation Throughout Adulthood: A Longitudinal Study of Women

INTRODUCTION

Smoking cessation is more than 50% heritable. Genetic studies of smoking cessation have been limited by short-term follow-up or cross-sectional design.

AIMS AND METHODS

This study tests single nucleotide polymorphism (SNP) associations with cessation during long-term follow-up throughout adulthood in women. The secondary aim tests whether genetic associations differ by smoking intensity. Associations between 10 SNPs in CHRNA5, CHRNA3, CHRNB2, CHRNB4, DRD2, and COMT and the probability of smoking cessation over time were evaluated in two longitudinal cohort studies of female nurses, the Nurses' Health Study (NHS) (n = 10 017) and NHS-2 (n = 2793). Participant follow-up ranged from 2 to 38 years with data collected every 2 years.

RESULTS

Women with the minor allele of either CHRNA5 SNP rs16969968 or CHRNA3 SNP rs1051730 had lower odds of cessation throughout adulthood [OR = 0.93, p-value = .003]. Women had increased odds of cessation if they had the minor allele of CHRNA3 SNP rs578776 [OR = 1.17, p-value = .002]. The minor allele of DRD2 SNP rs1800497 was associated with lower odds of cessation in moderate-to-heavy smokers [OR = 0.92, p-value = .0183] but increased odds in light smokers [OR = 1.24, p-value = .096].

CONCLUSIONS

Some SNP associations with short-term smoking abstinence observed in prior studies were shown in the present study to persist throughout adulthood over decades of follow-up. Other SNP associations with short-term abstinence did not persist long-term. The secondary aim findings suggest genetic associations may differ by smoking intensity.

IMPLICATIONS

The results of the present study expand on previous studies of SNP associations in relation to short-term smoking cessation to demonstrate some of these SNPs were associated with smoking cessation throughout decades of follow-up, whereas other SNP associations with short-term abstinence did not persist long-term. The rate of relapse to smoking remains high for several years after quitting smoking, and many smokers experience multiple quit attempts and relapse episodes throughout adulthood. Understanding genetic associations with long-term cessation has potential importance for precision medicine approaches to long-term cessation management.

Perceived Health and Capacity to Cope With Stress in Recent Ex-smokers: Impact of Vaping Versus Quitting All Nicotine

INTRODUCTION

Little is known about the continued use of nicotine following smoking cessation on perceived well-being in comparison to complete cessation of nicotine use.

AIMS AND METHODS

To explore aspects of perceived well-being and coping among recent ex-smokers as a function of vaping status. Ever-daily smokers in the International Tobacco Control 4 country smoking and vaping surveys in 2016 (w1 N = 883) and 2018 (w2 N = 1088). Cross-sectional associations and longitudinal samples for those who quit between waves and those who quit at w1 and maintained abstinence to w2. Main outcome measures were: Past 30 days of depression symptoms, perceived stress, stress management since quitting, and change in perceived day-to-day health.

RESULTS

In the cross-sectional analyses vapers were more likely to report both improved stress management (aOR = 1.71, 95% CI 1.23-2.36) and perceived day-to-day health (aOR = 1.65, 95% CI 1.26-2.16) than nicotine abstainers. In the longitudinal analyses, smokers who switched to vaping between waves (n = 372) were more likely to report depression symptoms at w2 (aOR = 2.00, 95% CI 1.09-3.65) but reported improved perceived health (aOR = 1.92, 95% CI 1.16-3.20). For the past daily smokers who remained quit between waves (n = 382), vapers were more likely to report improved stress management relative to abstainers (RRR = 5.05. 95% CI 1.19-21.40). There were no other significant differences between vapers and nicotine abstainers.

CONCLUSIONS

There is little evidence to support the view that perceptions of well-being deteriorate in vapers compared to complete nicotine abstainers in the immediate years after smoking cessation.

IMPLICATIONS

This study could find no conclusive evidence that the continued use of nicotine via e-cigarettes was detrimental to health compared to completely stopping nicotine intake altogether. Our results would suggest that continuing to use nicotine may even result in some benefits in the short term such as improved stress management, however further longitudinal studies are required to examine if these effects are restricted to the early post-quitting phase and whether other positive or negative effects on psychosocial health emerge in the future.

Associations in Cigarette Smoking and Health Conditions by Race/Ethnicity Among a Diverse Sample of Patients Receiving Treatment in a Federally Qualified Health Care Setting in Chicago

Purpose

To examine the association of cigarette use and smoking-related health conditions by race/ethnicity among diverse and low-income patients at a federally qualified health center (FQHC).

Methods

Demographics, smoking status, health conditions, death, and health service use were extracted from electronic medical data for patients seen between September 1, 2018, and August 31, 2020 (n=51,670). Smoking categories included everyday/heavy smoker, someday/light smoker, former smoker, or never smoker.

Results

Current and former smoking rates were 20.1% and 15.2%, respectively. Males, Black, White, non-partnered, older, and Medicaid/Medicare patients were more likely to smoke. Compared with never smokers, former and heavy smokers had higher odds for all health conditions except respiratory failure, and light smokers had higher odds of asthma, chronic obstructive pulmonary disease, emphysema, and peripheral vascular disease. All smoking categories had more emergency department visits and hospitalizations than never smokers. The associations between smoking status and health conditions differed by race/ethnicity. White patients who smoked had a greater increase in odds of stroke and other cardiovascular diseases compared with Hispanic and Black patients. Black patients who smoked had a greater increase in odds of emphysema and respiratory failure compared with Hispanic patients. Black and Hispanic patients who smoked had a greater increase in emergency care use compared with White patients.

Conclusion

Smoking was associated with disease burden and emergency care and differed by race/ethnicity.

Health Equity Implications

Resources to document smoking status and offer cessation services should be increased in FQHCs to promote health equity for lower income populations.

A systematic review of genetic variation within nicotinic acetylcholine receptor genes and cigarette smoking cessation

BACKGROUND

Nicotine produces its effects by binding to nicotinic acetylcholine receptors (nAChRs). Variants of genes encoding properties of nAChRs are candidates for affecting likelihood of smoking cessation.

METHODS

A systematic review was conducted summarizing evidence of associations between single nucleotide polymorphisms (SNPs) of nAChR genes and smoking cessation. From 24 articles meeting inclusion criteria, summary odds ratios (ORs) for associations between nine SNPs and smoking cessation were calculated from 26 studies (N = 233-29,072) stratified by gene, ancestry, study design, and pharmacotherapy; SNPs in linkage disequilibrium were pooled. Results for a tenth SNP from two GWAS were summarized.

RESULTS

People of European ancestry with minor alleles of CHRNA5 rs16969968 and CHRNA3 rs1051730 had longer time to cessation [HR = 0.90, 95 % CI 0.88 - 0.92 (n = 2 studies)] and lower odds of cessation [OR = 0.88, 95 % CI 0.80 - 0.97 (n = 5 cohort studies), OR = 0.64, 95 % CI 0.45 - 0.90 (n = 4 placebo arms)]. Risk of persistent smoking associated with these alleles was attenuated in smokers receiving nicotine replacement therapy (NRT). Recipients of bupropion alone or with NRT with these alleles had higher, though not statistically significant, odds of cessation. Results for CHRNA5 rs588765 and rs680244 were similar to rs16969968/rs1051730 findings. Evidence was limited for other SNPs.

CONCLUSION

Evidence consistently indicates the minor alleles of four SNPs within CHRNA3 or CHRNA5 are risk alleles for cessation failure. Analysis by pharmacotherapy revealed bupropion may be the most efficacious intervention for people with these alleles.

Multifactorial Etiology of Adolescent Nicotine Addiction: A Review of the Neurobiology of Nicotine Addiction and Its Implications for Smoking Cessation Pharmacotherapy

Nicotine is the primary pharmacologic component of tobacco, and its highly addictive nature is responsible for its widespread use and significant withdrawal effects that result in challenges to smoking cessation therapeutics. Nicotine addiction often begins in adolescence and this is at least partially attributed to the fact that adolescent brain is most susceptible to the neuro-inflammatory effects of nicotine. There is increasing evidence for the involvement of microglial cells, which are the brain's primary homeostatic sensor, in drug dependence and its associated behavioral manifestations particularly in the adolescent brain. A hallmark of neuro-inflammation is microglial activation and activation of microglia by nicotine during adolescent development, which may result in long-term addiction to nicotine. This non-systematic review examines multifactorial etiology of adolescent nicotine addiction, neurobiology of nicotine addiction and the potential mechanisms that underlie the effects of nicotine on inflammatory signaling in the microglia, understanding how nicotine affects the adolescent brain. We speculate, that modulating homeostatic balance in microglia, could have promising therapeutic potential in withdrawal, tolerance, and abstinence-related neural adaptations in nicotine addiction, in the adolescent brain. Further, we discuss nicotine addiction in the context of the sensitization-homeostasis model which provides a theoretical framework for addressing the potential role of microglial homeostasis in neural adaptations underlying nicotine abuse.

Longitudinal associations between marijuana and cigar use in young adults

BACKGROUND

We assess the longitudinal associations between marijuana and cigar (little cigars and cigarillos [LCCs] and large cigars) use on subsequent initiation of marijuana and cigar use.

METHODS

Data are from a cohort study of 2189 young adults recruited in fall 2010 from 11 colleges in the Southeast. We used discrete-time survival analysis to examine whether ever use of marijuana at baseline (spring 2011, freshman year) predicted initiation of LCCs and large cigars and whether ever use of these cigar products predicted initiation of marijuana use across 10 waves of data collection (2011-2018).

RESULTS

The sample was 65.3 % female, 83.6 % White, 5.9 % Hispanic, and 61.8 % had college-educated mothers. At baseline, 70 % reported never using LCCs, 71 % reported never using large cigars, and 74 % reported never using marijuana. Ever use of marijuana at baseline was associated with an increased risk of LCC initiation (Incident rate ratio [IRR] = 1.6, 95 %CI = 1.0, 2.5) but not large cigar initiation. Ever use of LCCs (IRR = 1.4, 95 %CI = 1.1, 1.8) and ever use of large cigars (IRR = 1.3, 95 %CI = 1.1, 1.8) at baseline both predicted initiation of marijuana use.

CONCLUSIONS

Our findings support growing evidence that marijuana and LCCs are strongly associated and use of one substance predicts use of the other. In contrast to studies of adults, we also found that young adults who have tried large cigars may be at increased risk for subsequent marijuana use. These findings highlight the need to consider each product as a potential gateway of the other when developing interventions for young adults.

The Influence of Exposure to Smoking in Movies on Cigarette Cravings among Adolescents: A Contextual Quasi-Experimental Model

This study explored the socio-contextual characteristics of adolescents that led them to have increased cigarette cravings when exposed to smoking scenes in films. We analyzed online survey data collected from a representative sample of 955 Korean adolescents. Our dependent variable was change in cigarette cravings after watching a smoking scene; independent variables included sex, age, school type, allowance, smoking experience, and parental smoking. We used paired t-tests to identify the differences in cigarette cravings modified by individual characteristics, and we performed logistic regression to explore the influences on these changes in cravings. The high school students investigated herein had significantly stronger cigarette cravings after they watched smoking scenes than they did prior to watching these scenes (t = -5.039, p < 0.001). The cravings were significantly higher after watching the clips among non-smokers (t = -4.264, p < 0.001) and participants who had at least one parent who smoked (t = -2.114, p < 0.05); non-smoking adolescents were also more likely to crave cigarettes after they watched smoking scenes than were smokers (odds ratio = 6.90, p < 0.001). Korean adolescents who did not smoke and those who had at least one parent who smoked showed the strongest cigarette cravings after being exposed to smoking in films. Consequently, more effective prevention strategies should be developed that recognize this tendency when regulating smoking scenes in movies or implementing related campaigns among adolescents.

Measures of nicotine dependence enhance interpretation of number of cigarettes smoked in youth smoking surveillance

BACKGROUND

Nicotine dependence (ND) symptoms can occur soon after first puff, so that stopping smoking becomes difficult well before 100 cigarettes lifetime is attained. Yet some surveillance systems do not monitor ND symptoms and 100-cigarettes lifetime is used in at least one surveillance system to define current smokers. To assess whether these features limit interpretation of grade-specific data in surveillance, we described smoking and ND symptoms across grade in incident vs. prevalent smokers, and in smokers according to 100-cigarettes lifetime.

METHODS

Data were available in an investigation of 1294 grade 7 students from 10 Montreal-area high schools followed every 3 months from grade 7 to 11. Analyses described cigarette consumption, 100-cigarette lifetime consumption, cravings, withdrawal symptoms, mFTQ nicotine dependence and ICD-10 tobacco dependence by grade among past 3-month smokers.

RESULTS

Despite low cigarette consumption, 21-30% of grade 7 smokers reported ND symptoms. This increased to 27-44% in grade 8 and remained stable thereafter despite increased cigarette consumption. In grade 7, 10% of all smokers had not attained the 100-cigarette milestone but were already dependent. In grade 8, 9, 10 and 11, these proportions were 12%, 8%, 6% and 6%, respectively.

CONCLUSIONS

ND symptoms should be monitored in youth surveillance systems since they tell a different "story" than cigarettes and their appearance may represent a critical "point-of-no-return." Interventions for incident smokers are needed across grades to stop smoking before ND manifests. Without a shift in focus toward incident rather than established smokers, many children who try cigarettes will become addicted.

Habits, Quick and Easy: Perceived Complexity Moderates the Associations of Contextual Stability and Rewards With Behavioral Automaticity

BACKGROUND

Habits have been proposed to develop as a function of the extent to which a behavior is rewarded, performed frequently, and executed in a stable context. The present study examines how each of these factors are associated with behavioral automaticity across a broad variety of behaviors drawn from previous habits research. This study further assesses how perceived complexity of the behavior influences the associations of rewards, frequency, and contextual stability with automaticity.

METHODS

Participants (N = 459) completed an online survey assessing their experiences and engagement with 25 different behaviors, including exercise, handwashing, smoking, and medication adherence, among others. Exploratory factor analysis validated a short, relatively novel scale of perceived behavioral complexity, and multilevel analyses grouped by participant were used to examine the factors that contribute to automaticity.

RESULTS

Across behaviors, frequency, contextual stability, and perceived rewards were positively associated with automaticity. Perceived complexity was negatively associated with automaticity and moderated the influence of contextual stability and rewards, but not frequency, on automaticity. Both contextual stability and rewards were stronger predictors of automaticity when behavioral complexity was high rather than low, as predicted; in addition, when contextual stability was high, more complex behaviors showed greater automaticity than simpler behaviors.

CONCLUSION

The results of this study confirm that behavioral frequency, rewards, and contextual stability are each independently associated with automaticity across a spectrum of behaviors. This study further demonstrates that perceived complexity of a behavior moderates the extent to which contextual stability and rewards are associated with automaticity. The results affirm a need to further understand the components of habits and how they differ across varying behaviors.

Ecological momentary assessment of smoking behaviors in native and converted intermittent smokers

BACKGROUND AND OBJECTIVES

About 22% of adult smokers in the U.S. are intermittent cigarette smokers (ITS). ITS can be further classified as native ITS who never smoked daily and converted ITS who formerly smoked daily but reduced to intermittent smoking. Ecological momentary assessment (EMA) was conducted to determine the behaviors and experiences that are associated with the decision to smoke.

METHODS

The study included 24 native ITS and 36 converted ITS (N = 60) from the Pennsylvania Adult Smoking Study. A baseline questionnaire, daily log, and an EMA smoking log that assessed emotions, activities, and smoking urges was filled out with each cigarette for 1 week to capture 574 smoking sessions.

RESULTS

Both groups had very low levels of cigarette dependence. Both groups were more tempted to smoke in positive or negative situations than situations associated with habituation. EMA showed that the most common emotional state during smoking sessions was positive (47%), followed by negative (32%), neutral (16%), and mixed (5%) emotions. Smokers were more likely to smoke during activities of leisure (48%) than during performative duties (29%), social (16%) or interactive occasions (7%). Converted ITS were more likely to smoke alone compared to native ITS (p < .001).

DISCUSSION AND CONCLUSIONS

ITS report minimal levels of dependence when captured on traditional scales of nicotine dependence, yet experience loss of autonomy and difficulty quitting. The majority of the ITS reported positive emotions and leisure activities while smoking, and smoked during the evening.

SCIENTIFIC SIGNIFICANCE

The current paper identifies environmental and behavioral factors that are associated with smoking among ITS in real time. (Am J Addict 2018;27:131-138).

Tobacco Smoking and Brain Endogenous Opioid Release: More Than Nicotine Alone

INTRODUCTION

The effects of smoking denicotinized (denic) and average nicotine (avnic) tobacco cigarettes were studied on brain mu opioid receptor binding by positron emission tomography with 11C carfentanil. The results indicated the importance of physiological and psychological effects induced by denic smoking.

METHODS

Regional mu opioid binding potential (nondisplaceable binding potential, BPND) was measured in 20 adult male overnight abstinent chronic tobacco smokers. The denic sessions were conducted about 8:00 am followed by avnic sessions about 2 hours later. Venous plasma nicotine levels and scores of craving to smoke were assessed before and after each smoking session. Fagerstrom scores of nicotine dependence were determined. Pearson's and Spearman's correlation tests were used to examine associations between BPND and other smoking parameters.

RESULTS

Surprisingly, the very low plasma nicotine peak levels after denic smoking (mean ± SD: 3.3 ± 1.8 ng/mL) were significantly correlated with BPND after denic and avnic smoking. Equally surprising no association was found between nicotine levels after avnic smoking and BPND. Delta craving scores and Fagerstrom scores were correlated with both BPND after denic and avnic in several brain regions.

CONCLUSIONS

Very small amounts of nicotine, psychological and behavioral effects of denic smoking appear to have important actions on the endogenous mu opioid system.

IMPLICATIONS

Associations between very low venous plasma nicotine levels after denic smoking and regional brain mu opioid receptor availability are a surprising "placebo" effect. Delta craving and Fagerstrom scores were correlated with BPND in several brain regions including amygdala, hippocampus, insula, nucleus accumbens, putamen, and ventral striatum. This study is limited by modest Power (mean 1 - β = 0.6) for all correlation analyses.

The concept of exposure when selecting comparison groups for determining individual susceptibility to addiction to cigarette smoking

Smoking is a leading cause of preventable death. The effect of tobacco is even more contundent in people with mental illness and, in general, cigarette smoking addiction is influenced by genetic factors. The opioid system is involved in the mesolimbic reward system, which is of great importance in addictive behaviors, such as smoking and is influenced by genes such as the OPRM1. The aim of this study was to evaluate if selecting a comparison group that include light smokers versus people that never smoked impacts the results of genetic association studies. In addition, to evaluate the genetic association in different groups of smokers by analyzing independent covariates such as mental illness and clinical dental data. All subjects were participants of the Dental Registry and DNA Repository project. Genotyping was carried out using TaqMan chemistry for two markers in OPRM1 (rs553202 and rs7755635). Logistic regression analyses were performed as implemented in PLINK. The established value for alpha was 5%, and the Hardy-Weinberg equilibrium was evaluated by the chi-square test with one degree of freedom for each marker. 1,897 patients were included, which were allocated to eight distinct groups, according to the frequency and quantity of cigarettes smoked and mental illness status. There was no significant association between the two markers in OPRM1 and smoking. When mental illness and dental clinical data (tooth loss, dental caries, and periodontitis) were used as covariates, there were associations between heavy smoking and OPRM1, when non-smokers were used as comparison. We did not have diet or microbiome data to consider for these dental analyses and suggest that these kinds of data should be always incorporated in the future. Significant results were found only when the covariables mental illness and oral clinical data were added to the analysis.

Australian School Student Perceptions of Effective Anti-tobacco Health Warnings

Background: Recent research posits that anti-tobacco health warnings on cigarette packaging may gradually lose their effectiveness in dissuading adolescents from tobacco products several years after implementation. Health warnings on individual cigarette sticks represent a novel warning medium, and may further educate adolescents on the dangers associated with smoking, and reduce tobacco experimentation amongst this vulnerable population. Methods: In an online survey of school students in Queensland, Australia, participants were requested to rate (on five-point Likert scales) and comment on the perceived effectiveness of current cigarette packaging warnings, and 12 text warnings on cigarette sticks, in preventing non-smokers from smoking, and encouraging current smokers to quit. The warnings were divided into four themes to establish the most effective types of anti-tobacco messages: mortality statistics, health condition consequences, social and financial consequences, and supportive messages. These themes were based on current anti-tobacco interventions within Australia, and the rising cost of tobacco products, and designed to align with the Health Belief Model. Results: Participants (N = 150; Age = 15-18) from five schools completed the survey, and generally viewed current packaging warnings as gross and disgusting, and rating them as somewhat effective in preventing non-smokers from smoking. Current warnings were however considered less effective in prompting current smokers to quit with participants describing them as being un-relatable to teenagers, and smokers as having become desensitized to the warnings used. One theme of cigarette-stick warning (mortality statistics) was rated as significantly more effective (p < 0.001) than current cigarette packaging, with an odds ratio (OR) of 2.77 (95% confidence interval [CI]: 1.67-4.62). Overall, warnings were considered to be 4.71 times (95%CI: 2.72-6.43, p < 0.001) more effective on non-smokers than on smokers. Over three-quarters of participants supported using health warnings on individual cigarette sticks. Conclusions: Current cigarette packaging warnings have retained some effectiveness in dissuading adolescents from smoking, though novel and thought-provoking text-only warnings on cigarette sticks may serve as an additional intervention in reducing tobacco use. Further research requires identification of the most effective warnings, and the perceptions of a more diverse participant base.

Patterns in first and daily cigarette initiation among youth and young adults from 2002 to 2015

This study’s objective was to describe long-term trends and patterns in first cigarette use (cigarette initiation) and daily cigarette use (daily initiation) among youth and young adults in the U.S. We used cross-sectional survey data from the National Survey on Drug Use and Health, 2002–2015, to estimate annual incidence of first cigarette use (N = 270,556) and first daily cigarette use (N = 373,464) for each year by age groups, race/ethnicity and gender, examining trends over time and the average annual change in initiation for each group. Several clear patterns emerged: 1) cigarette initiation and daily initiation significantly decreased over time among those aged 12–14 and 15–17 and these trends were consistent among nearly all racial/ethnic and gender subgroups; 2) among 18–21 year olds, cigarette initiation sharply increased through 2009, surpassing rates among 15–17 year olds, and sharply declined through 2015 while remaining higher than rates among the younger group, and this trend was consistent for almost all racial/ethnic subgroups; 3) daily initiation for those aged 18–21 significantly declined, and this was significant among most subgroups 4) there was no change in cigarette initiation and daily initiation for 22–25 year olds overall and most subgroups; 5) there was a significant increase in cigarette initiation for 22–25 year old Hispanics males and daily initiation for 22–25 year old males. This study provides a comprehensive look at trends in cigarette and daily initiation among U.S. youth and young adults. Despite notable declines in smoking initiation among youth and young adult populations over the last two decades, targeted prevention and policy efforts are needed for subgroups at higher risk, including young adults and Hispanic males.

Perceptions of Alternative Tobacco Products, Anti-tobacco Media, and Tobacco Regulation among Young Adults: A Qualitative Study

Objectives With increased alternative tobacco product (ATP) use and lagging public health action, we explored perceptions of ATPs, anti-tobacco messaging, and tobacco regulation among young adults. Methods Semi-structured interviews were conducted with 60 Georgia college students aged 18-25 using: (1) cigarettes, little cigars/cigarillos (LCCs), smokeless tobacco, or e-cigarettes ≥15 days of the past 30; or (2) hookah ≥10 of the past 30 days (due to lower frequency of use). Of 99 participants recruited, 80 consented, and 60 participated. Results Participants were on average 21.01 years old (SD = 2.07), 56.7% women, and 65.0% black; 56.7% reported current use of cigarettes, 43.3% LCCs, 26.7% smokeless tobacco, 45.0% e-cigarettes, and 41.7% hookah. Cigarettes were perceived as most harmful to health and most addictive. E-cigarettes and hookah were generally regarded as lowest risk. Many indicated that ATP risk information was limited or inaccessible and that most anti-tobacco campaigns were irrelevant to ATPs. Participants requested more research and dissemination of evidence regarding ATP risks and need for ATP regulation. Conclusions In light of low risk perceptions regarding ATPs among young adults, research, anti-tobacco campaigns, and regulation must address their known and potential risks.

Correlates of cannabis vape-pen use and knowledge among U.S. college students

INTRODUCTION

The proliferation of electronic devices, such as vape-pens, has provided alternative means for cannabis use. Research has found cannabis-vaping (i.e., vape-pen use) is associated with lower perceived risks and higher cannabis use. Knowledge of these products may increase likelihood of subsequent use. As policies for cannabis shift, beliefs that peers and family approve of this substance use (injunctive norms) increase and there has been an increase in vape-pen use among young adults (18-35 year olds); however, correlates thereof remain unknown. Young adults often engage in cross-substance use with cannabis and alcohol, making alcohol a potential correlate of cannabis vape-pen use and knowledge. Therefore, we examined alcohol use and other potential correlates of vape-pen use and knowledge among a sample of university students.

METHODS

This secondary data analysis utilized surveys at multiple colleges in the U.S. (N = 270). Alcohol use, social anxiety, cannabis expectancies, injunctive and descriptive norms and facets of impulsivity were examined as correlates of vape-pen use and knowledge using bivariate correlations and logistic regressions.

RESULTS

Alcohol use was correlated with cannabis vape-pen use and knowledge. Frequency of cannabis use, peer injunctive norms, and positive expectancies were associated with increased likelihood of vape-pen use. Lack of premeditation, a facet of impulsivity, was associated with cannabis vape-pen knowledge.

CONCLUSIONS

Given the unknown nature and consequences of cannabis vape-pens, the present findings offer valuable information on correlates of this behavior. Further, correlates of knowledge of vape-pens may point to areas for education and clinical intervention to prevent heavy cannabis vape-pen use.

Electronic cigarette use in youths: a position statement of the Forum of International Respiratory Societies

Children and adolescents are highly susceptible to nicotine addiction, which affects their brain development, even in those who smoke infrequently. Young people who become addicted to nicotine are at greater risk of becoming lifelong tobacco consumers. The use of nicotine-delivering electronic cigarettes has risen dramatically among youths worldwide. In addition to physical dependence, adolescents are susceptible to social and environmental influences to use electronic cigarettes. The product design, flavours, marketing, and perception of safety and acceptability have increased the appeal of electronic cigarettes to young people, thus leading to new generations addicted to nicotine. Moreover, there is growing evidence that electronic cigarettes in children and adolescents serve as a gateway to cigarette smoking. There can be no argument for harm reduction in children. To protect this vulnerable population from electronic cigarettes and other nicotine delivery devices, we recommend that electronic cigarettes be regulated as tobacco products and included in smoke-free policies. Sale of electronic cigarettes should be barred to youths worldwide. Flavouring should be prohibited in electronic cigarettes, and advertising accessible by youths and young adults be banned. Finally, we recommend greater research on the health effects of electronic cigarettes and surveillance of use across different countries.

Testing environment shape differentially modulates baseline and nicotine-induced changes in behavior: Sex differences, hypoactivity, and behavioral sensitization

In those who use nicotine, the likelihood of dependence, negative health consequences, and failed treatment outcomes differ as a function of gender. Women may be more sensitive to learning processes driven by repeated nicotine exposure that influence conditioned approach and craving. Sex differences in nicotine's influence over overt behaviors (i.e. hypoactivity or behavioral sensitization) can be examined using passive drug administration models in male and female rats. Following repeated intravenous (IV) nicotine injections, behavioral sensitization is enhanced in female rats compared to males. Nonetheless, characteristics of the testing environment also mediate rodent behavior following drug administration. The current experiment used a within-subjects design to determine if nicotine-induced changes in horizontal activity, center entries, and rearing displayed by male and female rats is detected when behavior was recorded in round vs. square chambers. Behaviors were recorded from each group (males-round: n=19; males-square: n=18; females-square: n=19; and females-round: n=19) immediately following IV injection of saline, acute nicotine, and repeated nicotine (0.05mg/kg/injection). Prior to nicotine treatment, sex differences were apparent only in round chambers. Following nicotine administration, the order of magnitude for the chamber that provided enhanced detection of hypoactivity or sensitization was contingent upon both the dependent measure under examination and the animal's biological sex. As such, round and square testing chambers provide different, and sometimes contradictory, accounts of how male and female rats respond to nicotine treatment. It is possible that a central mechanism such as stress or cue sensitivity is impacted by both drug exposure and environment to drive the sex differences observed in the current experiment. Until these complex relations are better understood, experiments considering sex differences in drug responses should balance characteristics of the testing environment to provide a complete interpretation of drug-induced changes to behavior.

Convergent Neuronal Plasticity and Metaplasticity Mechanisms of Stress, Nicotine, and Alcohol

Stress and tobacco smoking are risk factors for alcoholism, but the underlying neural mechanisms are not well understood. Although stress, nicotine, and alcohol have broad, individual effects in the brain, some of their actions converge onto the same mechanisms and circuits. Stress and nicotine augment alcohol-related behaviors, in part via modulation of alcohol-evoked neuronal plasticity and metaplasticity mechanisms. Stress modulates alcohol-evoked plasticity via the release of signaling molecules that influence synaptic transmission. Nicotine also activates some of the same signaling molecules, cells, and circuits, producing a convergence of both stress and nicotine onto common plasticity mechanisms that influence alcohol self-administration. We describe several forms of alcohol-induced plasticity, including classic Hebbian plasticity at glutamatergic synapses, and we highlight less appreciated forms, such as non-Hebbian and GABAergic synaptic plasticity. Risk factors such as stress and nicotine initiate lasting neural changes that modify subsequent alcohol-induced synaptic plasticity and increase the vulnerability to alcohol addiction.

12h abstinence-induced right anterior insula network pattern changes in young smokers

BACKGROUND

The strong craving to smoke is a core factor of smoking abstinence that precipitates relapse. Insula plays critical roles in maintaining nicotine dependence, especially in the interoceptive awareness of craving. Despite evidence indicating a link between insula and abstinence-induced craving, less is known about the neural basis of abstinence-induced craving from the circuit level of insula.

METHODS

The present study examined the effects of 12h of abstinence from smoking on the resting state functional connectivity (RSFC) of anterior (AI) and posterior insula in young smokers using a within-subject design. Thirty-three young male smokers underwent functional magnetic resonance imaging scanning on two separate sessions: (1) smoking satiety and (2) abstinence (after ≥12h of smoking deprivation), in counterbalanced order. Multiple regression analysis was applied to investigate the possible relationships between the RSFC changes of insula (abstinence minus satiety) and the abstinence-induced craving changes.

RESULTS

Smoking abstinence state (versus satiety) was associated with increased RSFC between right AI and right medial orbitofrontal cortex (OFC), ventromedial prefrontal cortex as well as anterior cingulate cortex. The abstinence-induced RSFC changes between right AI and right lateral OFC was significantly correlated with the craving changes.

CONCLUSIONS

These findings improve the understanding of the effects of short-term smoking abstinence on insula circuit connectivity and may contribute new insights into the neural basis of abstinence-induced craving to smoke.

Extended nicotine self-administration increases sensitivity to nicotine, motivation to seek nicotine and the reinforcing properties of nicotine-paired cues

An array of pharmacological and environmental factors influence the development and maintenance of tobacco addiction. The nature of these influences likely changes across the course of an extended smoking history, during which time drug seeking can become involuntary and uncontrolled. The present study used an animal model to examine the factors that drive nicotine-seeking behavior after either brief (10 days) or extended (40 days) self-administration training. In Experiment 1, extended training increased rats' sensitivity to nicotine, indicated by a leftward shift in the dose-response curve, and their motivation to work for nicotine, indicated by an increase in the break point achieved under a progressive ratio schedule. In Experiment 2, extended training imbued the nicotine-paired cue with the capacity to maintain responding to the same high level as nicotine itself. However, Experiment 3 showed that the mechanisms involved in responding for nicotine or a nicotine-paired cue are dissociable, as treatment with the partial nicotine receptor agonist, varenicline, suppressed responding for nicotine but potentiated responding for the nicotine-paired cue. Hence, across extended nicotine self-administration, pharmacological and environmental influences over nicotine seeking increase such that nicotine seeking is controlled by multiple sources, and therefore highly resistant to change.

Nicotine and Tobacco as Substances of Abuse in Children and Adolescents

Nicotine is the primary pharmacologic component of tobacco, and users of tobacco products seek out its effects. The highly addictive nature of nicotine is responsible for its widespread use and difficulty with quitting. This technical report focuses on nicotine and discusses the stages of use in progression to dependence on nicotine-containing products; the physiologic characteristics, neurobiology, metabolism, pharmacogenetics, and health effects of nicotine; and acute nicotine toxicity. Finally, some newer approaches to cessation are noted.

Need for medication to complement catecholamines in smoking cessation of hardcore smokers

Many smokers find it difficult to stop smoking without assistance. The antidepressants bupropion and nortriptyline can aid smoking cessation. The main aim of this study was to understand the pathophysiology of smoking cessation better based on biological backgrounds. We investigated the following biological markers for any alterations during smoking cessation in the absence of pharmacotherapy: the dopamine metabolite homovanillic acid (HVA), the noradrenaline metabolite 3-methoxy-4-hydroxyphenylglycol (MHPG) and brain-derived neurotrophic factor (BDNF). Assessment and blood sampling were performed at a baseline (the start) time point and at a critical time point during smoking cessation. Seven of 30 smokers quit during a 16-week follow-up period; these smokers were defined as remission group from tobacco dependence. The remaining 23 smokers were categorized as hardcore smokers. The smoking group was compared with 23 non-smokers matched for age and gender. We compared blood levels of biological markers in each of the three groups. The hardcore smoker group showed significant decreases in HVA and MHPG levels between baseline and the critical time point (p=0.018 and p=0.033, respectively). However, the remission from tobacco dependence group exhibited no significant changes in any of the biomarkers examined. They had lower scores on the Minnesota nicotine withdrawal scale than the hardcore smoker group (p=0.002). The hardcore smoker group had higher MHPG and BDNF levels than the non-smoker group (p=0.002 and p<0.001, respectively). Hardcore smokers experience severe nicotine withdrawal symptoms. Nicotine withdrawal is associated with catecholamine deficiency. The resulting withdrawal symptoms make quitting difficult for hardcore smokers. These hardcore smokers may require medication to compensate for the catecholamine deficit. Non-nicotinic medications such as bupropion, nortriptyline, or varenicline may be required to bolster the catecholamine deficit in hardcore smokers.

Can tobacco dependence provide insights into other drug addictions?

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

The Quit Experience and Concerns of Smokers With Psychiatric Illness

INTRODUCTION

The purpose of this study is to better understand the quit experience and concerns of smokers with psychiatric illness (i.e., major depressive, anxiety, psychotic and bipolar disorders) in comparison with those without psychiatric illness.

METHODS

Smokers (N=732) with (n=430, 59%) and without psychiatric illness, recruited between June 2010 and March 2013 to participate in the FLEX (Flexible and Extended Dosing of Nicotine Replacement Therapy [NRT] and Varenicline in Comparison to Fixed-Dose NRT for Smoking Cessation) smoking-cessation trial, completed questionnaires assessing previously used cessation aids and reasons for relapse, and motivation and concerns about their upcoming quit attempt. These supplementary data analyses were conducted in May 2015.

RESULTS

The most commonly used cessation methods during previous attempts were nicotine replacement therapy (66.4%), cold turkey (59.7%), and bupropion (34.7%); no group differences were identified. Stress was the most common precipitator of relapse during previous attempts in all groups (43.6%), particularly among participants with depression and anxiety. Health was the most common motivation for the upcoming quit attempt (91%), followed by family/social pressures (28.1%) and cost (27.9%, particularly by smokers with psychotic disorders). Common pre-cessation concerns for the complete sample included: cravings (27.6%), stress (26.7%), and fear of failure (26%); participants with psychotic and anxiety disorders were most concerned about cravings, whereas the latter two concerns were more prominent for individuals with anxiety.

CONCLUSIONS

Findings reveal differences in the quit histories and concerns of smokers with or without psychiatric illness. Smokers with psychiatric illness are particularly vulnerable to relapse at times of stress and negative affect; interventions that emphasize alternative coping strategies and facilitate mood management are required.

DECOY: Documenting Experiences with Cigarettes and Other Tobacco in Young Adults

OBJECTIVES

We examined psychographic characteristics associated with tobacco use among Project DECOY participants.

METHODS

Project DECOY is a 2-year longitudinal mixed-methods study examining risk for tobacco use among 3418 young adults across 7 Georgia colleges/universities. Baseline measures included sociodemographics, tobacco use, and psychographics using the Values, Attitudes, and Lifestyle Scale. Bivariate and multivariable analyses were conducted to identify correlates of tobacco use.

RESULTS

Past 30-day use prevalence was: 13.3% cigarettes; 11.3% little cigars/cigarillos (LCCs); 3.6% smokeless tobacco; 10.9% e-cigarettes; and 12.2% hookah. Controlling for sociodemographics, correlates of cigarette use included greater novelty seeking (p < .001) and intellectual curiosity (p = .010) and less interest in tangible creation (p = .002) and social conservatism (p < .001). Correlates of LCC use included greater novelty seeking (p < .001) and greater fashion orientation (p = .007). Correlates of smokeless tobacco use included greater novelty seeking (p = .006) and less intellectual curiosity (p < .001). Correlates of e-cigarette use included greater novelty seeking (p < .001) and less social conservatism (p = .002). Correlates of hookah use included greater novelty seeking (p < .001), fashion orientation (p = .044), and self-focused thinking (p = .002), and less social conservatism (p < .001).

CONCLUSIONS

Psychographic characteristics distinguish users of different tobacco products.

CHRNA5/A3/B4 Variant rs3743078 and Nicotine-Related Phenotypes: Indirect Effects Through Nicotine Craving

OBJECTIVE

Nicotine craving is considered an important element in the persistence of cigarette smoking, but little is known about the role of craving in the widely recognized association between variants mapped to the neuronal nicotinic acetylcholine receptor (CHRN) genes on chromosome 15 and nicotine phenotypes.

METHOD

The associations between CHRNA5-CHRNA3-CHRNB4 variants and cigarettes per day (CPD), the Fagerström Test for Nicotine Dependence (FTND), and craving were analyzed in data from 662 lifetime smokers from an Israeli adult Jewish household sample. Indirect effects of genotype on nicotine phenotypes through craving were formally tested using regression and bootstrapping procedures.

RESULTS

At CHRNA3, allele G of rs3743078 was associated with increased craving, CPD, and FTND scores: Participants with one or two copies of the G allele had, on average, higher scores on the craving scale (p = .0025), more cigarettes smoked (p = .0057), and higher scores on the FTND (p =.0024). With craving in the model, variant rs3743078 showed a significant indirect effect through craving on CPD (p = .0026) and on FTND score (p = .0024). A sizeable proportion of the total rs3743078 effect on CPD (56.4%) and FTND (65.2%) was indirect through craving.

CONCLUSIONS

These results suggest that nicotine craving may play a central role in nicotine use disorders and may have utility as a therapeutic target.

Electronic cigarettes: a review of safety and clinical issues

This clinical case conference discusses 3 cases of patients using electronic cigarettes. Electronic cigarettes, also referred to as electronic nicotine delivery systems or "e-cigarettes," generally consist of a power source (usually a battery) and a heating element (commonly referred to as an atomizer) that vaporize a solution (e-liquid). The user inhales the resulting vapor. E-liquids contain humectants such as propylene glycol and/or vegetable glycerin, flavorings, and usually, but not always, nicotine. Each patient's information is an amalgamation of actual patients and is presented and then followed by a discussion of clinical issues.

A Two-Day Continuous Nicotine Infusion Is Sufficient to Demonstrate Nicotine Withdrawal in Rats as Measured Using Intracranial Self-Stimulation

Avoidance of the negative affective (emotional) symptoms of nicotine withdrawal (e.g., anhedonia, anxiety) contributes to tobacco addiction. Establishing the minimal nicotine exposure conditions required to demonstrate negative affective withdrawal signs in animals, as well as understanding moderators of these conditions, could inform tobacco addiction-related research, treatment, and policy. The goal of this study was to determine the minimal duration of continuous nicotine infusion required to demonstrate nicotine withdrawal in rats as measured by elevations in intracranial self-stimulation (ICSS) thresholds (anhedonia-like behavior). Administration of the nicotinic acetylcholine receptor antagonist mecamylamine (3.0 mg/kg, s.c.) on alternate test days throughout the course of a 2-week continuous nicotine infusion (3.2 mg/kg/day via osmotic minipump) elicited elevations in ICSS thresholds beginning on the second day of infusion. Magnitude of antagonist-precipitated withdrawal did not change with further nicotine exposure and mecamylamine injections, and was similar to that observed in a positive control group receiving mecamylamine following a 14-day nicotine infusion. Expression of a significant withdrawal effect was delayed in nicotine-infused rats receiving mecamylamine on all test days rather than on alternate test days. In a separate study, rats exhibited a transient increase in ICSS thresholds following cessation of a 2-day continuous nicotine infusion (3.2 mg/kg/day). Magnitude of this spontaneous withdrawal effect was similar to that observed in rats receiving a 9-day nicotine infusion. Our findings demonstrate that rats exhibit antagonist-precipitated and spontaneous nicotine withdrawal following a 2-day continuous nicotine infusion, at least under the experimental conditions studied here. Magnitude of these effects were similar to those observed in traditional models involving more prolonged nicotine exposure. Further development of these models, including evaluation of more clinically relevant nicotine dosing regimens and other measures of nicotine withdrawal (e.g., anxiety-like behavior, somatic signs), may be useful for understanding the development of the nicotine withdrawal syndrome.

First tobacco product tried: associations with smoking status and demographics among college students

INTRODUCTION

As the tobacco market expands, so too have the opportunities for youth to be introduced to nicotine. The goal of this study was to identify product choice for initial tobacco trial, correlates associated with product choice, and the relationship between first product and current cigarette smoking among college students.

METHODS

A cross-sectional web survey of 3146 first-year students at 11 universities in North Carolina and Virginia was conducted in fall 2010.

RESULTS

Weighted prevalence of ever use of tobacco was 48.6%. Cigarettes were the most common first product (37.9%), followed by cigars (29.3%), hookahs (24.6%), smokeless tobacco (6.1%), and bidis/kreteks (2.2%). Two thirds (65%) of current smokers initiated with cigarettes, but 16.4% started with cigars, 11.1% with hookahs, 5.7% with smokeless, and 1.7% with bidis/kreteks. Females were more likely to report their first product was cigarettes and hookahs, while males were more likely to start with cigars and smokeless tobacco. Compared to those whose first product trial occurred after the age of 18, younger age of initiation (17years or younger) was associated with cigarettes and smokeless as first products, while older age of initiation (18 or older) was associated with starting with hookahs and cigars. Dual or poly tobacco use was more common among those who initiated with hookahs and smokeless tobacco.

CONCLUSIONS

While over a third of students used cigarettes first, two thirds started with a non-cigarette product. Just about a third of current cigarette smokers initiated with a non-cigarette product, suggesting that those non-cigarette products may have facilitated escalation to cigarettes.

Parental smoke exposure and the development of nicotine craving in adolescent novice smokers: the roles of DRD2, DRD4, and OPRM1 genotypes

BACKGROUND

Among adolescent novice smokers, craving is often the first, and is the most reported, symptom of nicotine dependence. Until now, little has been known about the development of craving symptoms in novice smokers. The aim of this study was to identify specific genetic (i.e., DRD2 Taq1A, DRD4 48 bp VNTR, and OPRM1 A118G polymorphisms) and environmental mechanisms that underlie the emergence of both cue-induced and cognitive craving among adolescent novice smokers.

METHOD

A five-wave longitudinal, genetically-informed survey study was conducted with intervals of four months. The sample included 376 early adolescent smokers (12-13 years of age at baseline). Self-report questionnaires were completed regarding smoking behavior, observed parental smoking behavior, and both cue-induced and cognitive craving.

RESULTS

Data were analyzed with a latent growth curve approach. For both cue-induced and cognitive craving, significant interaction effects were found for DRD2 Taq1A with parental smoke exposure. A1-allele carriers did not seem to be influenced by the environment with regard to craving development. Adolescents who are homozygous for the A2-allele and who are more exposed to parental smoking experience the highest levels of both types of craving over time. No significant interaction effects were found between parental smoke exposure and DRD4 48 bp VNTR or OPRM1 A118G.

CONCLUSIONS

Previous studies identified DRD2 Taq1A A1-allele carriers as vulnerable to developing nicotine dependence. However, this study showed that parental smoking increased the chances of developing dependence more rapidly for early adolescents who are considered to be less sensitive to the rewarding effects of nicotine according to their DRD2 Taq1A genotype. It is thus especially important that these young people not be exposed to smoking in their social environment.

Nondaily smokers' experience of craving on days they do not smoke

Nondaily, or intermittent smokers (ITS), represent a growing pattern in adult smoking that needs to be explained by models of drug dependence. ITS regularly and voluntarily abstain from smoking, yet have difficulty quitting. We examine potential accounts of ITS' smoking by exploring their experience of craving and withdrawal on the days they abstain. For 3 weeks, 146 ITS and 194 daily smokers used the Ecological Momentary Assessment (EMA) to monitor craving, withdrawal, and smoking in real-time. ITS' craving (p < .001) and arousal (p < .001) were significantly lower on the 34.4% of days when they abstained (compared with days they smoked), and they experienced no increases in withdrawal symptoms. ITS who abstained for longer experienced lower craving, even on their first day of abstinence (p < .001). Within strata defined by longest duration of abstinence (1, 2-3, 4-6, ≥7 days), craving did not change over time, demonstrating no increase as resumption of smoking approached. Craving increased only at the moment smoking resumed. Furthermore, duration of abstinence runs varied more within persons than across persons. These findings contradict the predictions of a model positing that craving recurs at fixed intervals. Findings are consistent with the hypothesis that ITS' smoking is cued or primed by particular stimuli rather than by temporal cycles. These analyses demonstrate that ITS do not experience increased craving or withdrawal on days they do not smoke, and show neither signs of classical dependence nor regular cycles of craving and smoking.

A systematic review of secondhand tobacco smoke exposure and smoking behaviors: Smoking status, susceptibility, initiation, dependence, and cessation

OBJECTIVES

To examine the association between secondhand tobacco smoke exposure (SHSe) and smoking behaviors (smoking status, susceptibility, initiation, dependence, and cessation).

METHODS

Terms and keywords relevant to smoking behaviors and secondhand tobacco smoke exposure were used in a search of the PubMed database. Searches were limited to English language peer-reviewed studies up till December 2013. Included papers: a) had clearly defined measures of SHSe and b) had clearly defined measures of outcome variables of interest. A total of 119 studies were initially retrieved and reviewed. After further review of references from the retrieved studies, 35 studies were finally selected that met all eligibility criteria.

RESULTS

The reviewed studies consisted of thirty-five (89.7%) studies with differing measures of SHSe (including questionnaire and biological measures) and varying definitions of main outcome variables of interest between studies. The majority of the studies (77%) were cross-sectional in nature. The majority of studies found that SHSe was associated with greater likelihood of being a smoker, increased susceptibility and initiation of smoking, greater nicotine dependence among nonsmokers, and poorer smoking cessation.

CONCLUSIONS

The review found positive associations between SHSe and smoking status, susceptibility, initiation and nicotine dependence and a negative association with smoking cessation. In light of design limitations, future prospective and clinical studies are needed to better understand the mechanisms whereby SHSe influences smoking behaviors.

Development of the PROMIS coping expectancies of smoking item banks

OBJECTIVE

Smoking is a coping strategy for many smokers who then have difficulty finding new ways to cope with negative affect when they quit. This paper describes analyses conducted to develop and evaluate item banks for assessing the coping expectancies of smoking for daily and nondaily smokers.

METHODS

Using data from a large sample of daily (N = 4,201) and nondaily (N = 1,183) smokers, we conducted a series of item factor analyses, item response theory analyses, and differential item functioning (DIF) analyses (according to gender, age, and ethnicity) to arrive at a unidimensional set of items for daily and nondaily smokers. We also evaluated performance of short forms (SFs) and computer adaptive tests (CATs) for assessing coping expectancies of smoking.

RESULTS

For both daily and nondaily smokers, the unidimensional Coping Expectancies item banks (21 items) are relatively DIF free and are highly reliable (0.96 and 0.97, respectively). A common 4-item SF for daily and nondaily smokers also showed good reliability (0.85). Adaptive tests required an average of 4.3 and 3.7 items for simulated daily and nondaily respondents, respectively, and achieved reliabilities of 0.91 for both when the maximum test length was 10 items.

CONCLUSIONS

This research provides a new set of items that can be used to reliably assess coping expectancies of smoking, through a SF, CAT, or a tailored set selected for a specific research purpose.

Behavioral and Physiological Responses to Nicotine Patch Administration Among Nonsmokers Based on Acute and Chronic Secondhand Tobacco Smoke Exposure

INTRODUCTION

Despite the large amount that is known about the physical health effects of secondhand tobacco smoke (SHS) exposure, little is known about the behavioral health effects. Nicotine, the principle psychoactive substance in SHS, elicits subjective mood and physiological responses in nonsmokers. However, no studies have examined the subjective mood or physiological responses to nicotine in nonsmokers while accounting for prior chronic or acute SHS exposure.

METHODS

A 7-mg nicotine patch was administered to 17 adult nonsmokers for 2 hr. Main outcome measures obtained at ½ hr, 1 hr, and 2 hr were subjective behavioral drug effects (based on eleven 10-cm Visual Analog Scales [VASs]) and the physiological measures of heart rate, blood pressure, and serum nicotine levels. Analysis of outcome data was based on participants' chronic (using hair nicotine) or acute (using saliva cotinine) SHS exposure.

RESULTS

Greater chronic SHS exposure was negatively associated with pleasurable responses to nicotine administration ("drug feels good" score at 2-hr time point, Spearman's ρ = -.65, p < .004), whereas greater acute SHS exposure was associated with positive responses ("like feeling of drug" score at 2-hr time point, Spearman's ρ = .63, p < .01). There were no associations between chronic or acute exposure and physiological changes in response to nicotine administration.

DISCUSSION

The findings of this study may be useful in providing preliminary empirical data for future explorations of the mechanism whereby SHS exposure can influence behavioral outcomes in nonsmokers. Such studies can inform future interventions to reduce the physical and behavioral health risks associated with SHS exposure.

A comparison of adolescent smoking initiation measures on predicting future smoking behavior

Objectives

Evidence suggests that age at smoking initiation has implications for tobacco use, nicotine dependence, and resulting long-term health and chronic disease outcomes. The objective of the current study was to examine two different measures of smoking onset and to compare their validity in predicting future adolescent smoking survey.

Methods

Data from grades 9–12 students who participated in the 2012/2013 Youth Smoking Survey, a nationally-generalizable Canadian survey, and who had ever tried a cigarette, even a few puffs (n = 8126) were used in a multivariable logistic regression analysis to examine the association between age at smoking onset and current smoking behavior.

Results

Both “age at first puff” and “age at first whole cigarette” were significantly associated with current smoking status. Specifically, a delay of one year in the age at first puff was associated with lower odds of being a current smoker by 24% (AOR = 0.76, 95% CI = 0.73–0.79). Similarly, high school students who smoked their first whole cigarette at old age were less likely to report being a current smoker (AOR = 0.66, 95% CI = 0.62–0.71).

Conclusion

Efforts to prevent smoking uptake among youth, especially younger youth, are especially important in tobacco control efforts.

Perceived harm of tobacco products and individual schemas of a smoker in relation to change in tobacco product use over one year among young adults

INTRODUCTION

Given increases in nondaily smoking and alternative tobacco use among young adults, we examined the nature of change of various tobacco product use among college students over a year and predictors of use at one-year follow-up.

METHODS

An online survey was administered to students at six Southeast colleges and universities (N = 4,840; response rate = 20.1%) in Fall 2010, with attempts to follow up in Fall 2011 with a random subsample of 2,000 participants (N = 718; response rate = 35.9%). Data were analyzed from 698 participants with complete data regarding tobacco, marijuana, and alcohol use over a one-year period, perceived harm of tobacco use, and schemas of a "smoker" (as per the Classifying a Smoker Scale).

RESULTS

Baseline predictors of current smoking at follow-up included being White (p = .001), frequency of smoking (p < .001), alternative tobacco use (p < .001), and perceived harm of smoking (p = .02); marginally significant predictors included marijuana use (p = .06) and lower scores on the Classifying a Smoker Scale (p = .07). Baseline predictors of current smoking at follow-up among baseline nondaily smokers included more frequent smoking (p = .008); lower Classifying a Smoker Scale score was a marginally significant predictor (p = .06). Baseline predictors of alternative tobacco use at follow-up included being male (p = .007), frequency of smoking (p = .04), alternative tobacco use (p < .001), and frequency of alcohol use (p = .003); marginally significant predictors included marijuana use (p = .07) and lower perceived harm of smokeless tobacco (p = .06) and cigar products (p = .08).

CONCLUSIONS

Tobacco control campaigns and interventions might target schemas of a smoker and perceived risks of using various tobacco products, even at low levels.

Perceived harm, addictiveness, and social acceptability of tobacco products and marijuana among young adults: marijuana, hookah, and electronic cigarettes win

BACKGROUND

There has been an increase in non-daily smoking, alternative tobacco product and marijuana use among young adults in recent years.

OBJECTIVES

This study examined perceptions of health risks, addictiveness, and social acceptability of cigarettes, cigar products, smokeless tobacco, hookah, electronic cigarettes, and marijuana among young adults and correlates of such perceptions.

METHODS

In Spring 2013, 10,000 students at two universities in the Southeastern United States were recruited to complete an online survey (2,002 respondents), assessing personal, parental, and peer use of each product; and perceptions of health risks, addictiveness, and social acceptability of each of these products.

RESULTS

Marijuana was the most commonly used product in the past month (19.2%), with hookah being the second most commonly used (16.4%). The least commonly used were smokeless tobacco products (2.6%) and electronic cigarettes (4.5%). There were high rates of concurrent product use, particularly among electronic cigarette users. The most positively perceived was marijuana, with hookah and electronic cigarettes being second. While tobacco use and related social factors, related positively, influenced perceptions of marijuana, marijuana use and related social factors were not associated with perceptions of any tobacco product. Conclusions/Importance: Marketing efforts to promote electronic cigarettes and hookah to be safe and socially acceptable seem to be effective, while policy changes seem to be altering perceptions of marijuana and related social norms. Research is needed to document the health risks and addictive nature of emerging tobacco products and marijuana and evaluate efforts to communicate such risks to youth.

Perceived barriers to smoking cessation in selected vulnerable groups: a systematic review of the qualitative and quantitative literature

OBJECTIVES

To identify barriers that are common and unique to six selected vulnerable groups: low socioeconomic status; Indigenous; mental illness and substance abuse; homeless; prisoners; and at-risk youth.

DESIGN

A systematic review was carried out to identify the perceived barriers to smoking cessation within six vulnerable groups.

DATA SOURCES

MEDLINE, EMBASE, CINAHL and PsycInfo were searched using keywords and MeSH terms from each database's inception published prior to March 2014.

STUDY SELECTION

Studies that provided either qualitative or quantitative (ie, longitudinal, cross-sectional or cohort surveys) descriptions of self-reported perceived barriers to quitting smoking in one of the six aforementioned vulnerable groups were included.

DATA EXTRACTION

Two authors independently assessed studies for inclusion and extracted data.

RESULTS

65 eligible papers were identified: 24 with low socioeconomic groups, 16 with Indigenous groups, 18 involving people with a mental illness, 3 with homeless groups, 2 involving prisoners and 1 involving at-risk youth. One study identified was carried out with participants who were homeless and addicted to alcohol and/or other drugs. Barriers common to all vulnerable groups included: smoking for stress management, lack of support from health and other service providers, and the high prevalence and acceptability of smoking in vulnerable communities. Unique barriers were identified for people with a mental illness (eg, maintenance of mental health), Indigenous groups (eg, cultural and historical norms), prisoners (eg, living conditions), people who are homeless (eg, competing priorities) and at-risk youth (eg, high accessibility of tobacco).

CONCLUSIONS

Vulnerable groups experience common barriers to smoking cessation, in addition to barriers that are unique to specific vulnerable groups. Individual-level, community-level and social network-level interventions are priority areas for future smoking cessation interventions within vulnerable groups.

TRIAL REGISTRATION NUMBER

A protocol for this review has been registered with PROSPERO International Prospective Register of Systematic Reviews (Identifier: CRD42013005761).

Recalled first reactions to inhaling nicotine predict the level of physical dependence

BACKGROUND

The level of physical dependence is a measure of addiction that correlates highly with addiction-associated changes in brain structure. We sought to determine whether age at first inhalation and initial reactions to inhaling nicotine are related to level of physical dependence in early adulthood.

METHODS

Young adults (n=312; mean age=24 years; 51% female) from the Nicotine Dependence in Teens study who had smoked at least once in the preceding three months completed self-report questionnaires in 2011-12. We assessed level of physical dependence with three validated self-report items assessing 'wanting,' 'craving' and 'needing' triggered by nicotine deprivation. Survey items assessed smoking behavior, including age at first inhalation, and recalled first reactions to inhaling nicotine.

RESULTS

After adjusting for covariates, experiencing relaxation, heart racing/pounding, rush or "buzz" (OR=1.45; 95% CI: 1.08, 1.94) and dizziness (OR=1.58; 95% CI: 1.15, 2.18) at first nicotine inhalation were associated with an increased odds of being at a higher level of physical dependence in young adulthood; the association for experiencing relaxation (OR=1.78; 95% CI: 1.20, 2.64) and heart racing/pounding (OR=1.51; 95% CI: 1.00, 2.28) persisted after additionally controlling for all other first reactions. Neither age at first inhalation nor unpleasant first reactions predicted level of physical dependence.

CONCLUSIONS

In accordance with prior research, our findings suggest that smokers who are particularly sensitive to the pleasant, "buzz-related" and generally arousing effects of nicotine may be more likely to attain higher levels of physical dependence.

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.

Reasons for smoking among tri-ethnic daily and nondaily smokers

INTRODUCTION

Nondaily smokers experience adverse effects from tobacco use, yet they have been understudied compared to daily smokers. Understanding how reasons for smoking (RS) differ by smoking level, gender, and race/ethnicity could inform tailored interventions.

METHODS

A cross-sectional survey was administered through an online panel survey service to 2,376 current smokers who were at least 25 years of age. The sample was stratified to obtain equal numbers of 3 racial/ethnic groups (African American [AA], Latino, and White) across smoking level (native nondaily, converted nondaily, daily light, and daily moderate/heavy).

RESULTS

A 7-factor structure of a 20-item Modified Reasons for Smoking Scale (MRSS) was confirmed (each subscale alpha > 0.80). Each factor of the MRSS varied by smoking level, with nondaily smokers endorsing all RS less frequently than daily smokers (p < .0001). The 4 smoker subgroups incrementally differed from one another (p < .05) with several exceptions between converted nondaily and daily light smokers. Males reported stronger RS on 5 out of 7 reasons (p < .05). Females had higher scores on tension reduction/relaxation (p < .0001). Latinos reported stronger RS than Whites and AAs on all reasons (p < .05) except for tension reduction/relaxation (p > .05). AAs and Whites were comparable on all RS (p > .05).

CONCLUSIONS

The present study highlights considerable variability across smoking level, gender, and race/ethnicity in strength of RS. Addressing subgroup differences in RS may contribute to more sensitive and effective prevention and treatment efforts.

Reasons for Nondaily Smoking among Young Adults: Scale Development and Validation

INTRODUCTION

Given the increased rates of nondaily smoking and the lack of validated measures to assess factors related to nondaily smoking, we aimed to develop a measure of reasons for nondaily smoking among young adults. Specifically, we developed a scale assessing reasons or triggers for nondaily smoking and examined its reliability, factor structure, and concurrent validity.

METHODS

We administered an online survey to 2,000 students at six colleges in the Southeastern US, and 718 (35.9%) returned a completed survey. The current analyses focused on the 95 participants who reported nondaily smoking (i.e., smoking between 1 and 29 days of the past 30 days). In addition to the items created for scale development, measures included socio-demographics, other measures of motivation and confidence/self-efficacy, past smoking/quitting history, readiness to quit, and other psychosocial factors related to smoking.

RESULTS

The 19-item Reasons for Nondaily Smoking Scale (RNS) demonstrated an average score of 45.36 (SD = 15.55) and internal consistency (Cronbach's alpha of 0.79). Factor analysis of the items extracted four factors which accounted for 57.4% of score variance: Social influences; Enhancing buzzes and positive affect; Negative affect regulation; and Lack of concern of addiction. Concurrent and discriminant validity were documented.

CONCLUSIONS

Developing validated measures designed to assess factors associated with nondaily smoking will enhance our ability to address this growing public health concern. The development and validation of the RNS for young adults may be critical in informing our intervention strategies and potentially for effecting or predicting cessation among young adult nondaily smokers.

The development and expression of physical nicotine dependence corresponds to structural and functional alterations in the anterior cingulate-precuneus pathway

INTRODUCTION

Perturbations in neural function provoked by a drug are thought to induce neural adaptations, which, in the absence of the drug, give rise to withdrawal symptoms. Previously published structural data from this study indicated that the progressive development of physical dependence is associated with increasing density of white matter tracts between the anterior cingulum bundle and the precuneus.

METHODS

Using functional magnetic resonance imaging, we compared 11 smokers after 11 h of abstinence from nicotine and after satiation, with 10 nonsmoking controls, using independent component analysis for brain network comparisons as well as a whole brain resting-state functional connectivity analysis using the anterior cingulate cortex as a seed.

RESULTS

Independent component analysis demonstrated increased functional connectivity in brain networks such as the default mode network associated with the withdrawal state in multiple brain regions. In seed-based analysis, smokers in the withdrawal state showed stronger functional connectivity than nonsmoking controls between the anterior cingulate cortex and the precuneus, caudate, putamen, and frontal cortex (P < 0.05). Among smokers, compared to the satiated state, nicotine withdrawal was associated with increased connectivity between the anterior cingulate cortex and the precuneus, insula, orbital frontal gyrus, superior frontal gyrus, posterior cingulate cortex, superior temporal, and inferior temporal lobe (P < 0.02). The intensity of withdrawal-induced craving correlated with the strength of connectivity between the anterior cingulate cortex and the precuneus, insula, caudate, putamen, middle cingulate gyrus, and precentral gyrus (r = 0.60-0.76; P < 0.05).

CONCLUSIONS

In concordance with our previous report that structural neural connectivity between the anterior cingulate area and the precuneus increased in proportion to the progression of physical dependence, resting-state functional connectivity in this pathway increases during nicotine withdrawal in correlation with the intensity of withdrawal-induced craving. These findings suggest that smoking triggers structural and functional neural adaptations in the brain that support withdrawal-induced craving.

Dietary energy density is associated with obesity and other biomarkers of chronic disease in US adults

PURPOSE

Given the current prevalence of obesity, it is important to identify dietary factors that may aid in disease prevention. The objective of the present study was to evaluate the association between consumption of an energy-dense diet and established markers factors for chronic disease, including body weight and measures of body fatness.

METHODS

Data from a nationally representative sample of 9,551 adults ≥18 years who participated in the 2005-2008 National Health and Nutrition Examination Survey were analyzed. The association between dietary energy density (ED, energy per weight of food, kcal/g) and markers for obesity [including body mass index (BMI) and waist circumference (WC)], insulin insensitivity [including fasting glucose, insulin and homeostasis assessment model for insulin resistance (HOMA-IR)], and markers for inflammation was examined.

RESULTS

Dietary ED was positively associated with obesity in both men and women in multivariate models. Overall, obese adults had a significantly higher dietary ED than lean adults (p < 0.0001). Current smokers had significantly higher ED than non-smokers (2.00 vs. 1.75, p < 0.01), and it was determined that smoking status modified the relationship between ED and weight status in women (p interaction 0.03). In both sexes, there was a positive linear relationship between BMI and ED (p trend 0.01 and 0.0002, respectively); a linear trend between WC and ED was also observed in women (p trend <0.001) after adjusting for relevant cofactors. In women, ED was positively associated with HOMA-IR and fasting insulin; though, this relationship was not observed in men. No significant associations between ED and C-reactive protein were observed in either sex.

CONCLUSION

These findings support recent obesity and disease prevention recommendations to consume a diet low in ED.