Importance of Various E-Cigarette Device and E-Liquid Characteristics by Smoking Status among Young Adults Who Vape.

BACKGROUND: E-cigarette product characteristics are known to influence appeal among young adults. Understanding which characteristics appeal to individuals with (vs. without) a history of combusted tobacco use is essential for developing effective tobacco control policies. METHODS: Anonymous, self-report data were collected from young adults (18-30 years) who had used e-cigarettes in the past 30 days (n = 295) online via Prolific from September-October 2019. Using a visual analogue scale (range: 0-100), participants rated the importance of ten e-cigarette device and nine e-liquid characteristics. Adjusted linear regression models were used to evaluate the association of combusted tobacco use status (never, former, current) with mean rating scores for each of the nineteen characteristics. RESULTS: The most important e-cigarette device characteristics were price (Mean = 81.1; [SD = 17.9]), size (Mean = 75.5 [SD = 20.9]), and hit strength (Mean = 73.8 [SD = 20.4]) while the most important e-liquid characteristics were flavor (M = 85.1 [SD = 16.3]), price (M = 80.9 [SD = 18.4]), and nicotine level (M = 77.8 [18.9]). Differences by combusted tobacco use status were observed for device brand, temperature/voltage, customizability, color, and popularity, with the highest ratings generally observed among those concurrently using combustible tobacco products. For e-liquids, differences by use status were observed for flavor, price, and bottle type. Notably, those concurrently using combusted products rated flavor as less important than those with no history of combustible tobacco use (B=-5.01[95%CI=-9.97, -0.05]). CONCLUSIONS: The self-rated importance of e-cigarette device and e-liquid attributes varies by combustible tobacco use status among young adults which may be used to inform regulatory decisions regarding e-cigarette product characteristics.

Differentiating Reasons for Young Adult E-cigarette Use Using Maximum Difference Choice Models.

INTRODUCTION: Understanding the reasons young adults use e-cigarettes (ie, vape)-and whether these motivations vary across groups-is essential for informing tobacco regulatory efforts. AIMS AND METHODS: An online panel of young adults who vape (n = 230; age = 18-30 years) completed a maximum difference discrete choice task for 15 reasons for vaping. Over 9 choice sets, participants were presented a subset of 5 reasons and selected the most and least important. Hierarchical bayesian analysis estimated the relative importance of each reason. Latent class analysis (LCA) identified groups with similarly ranked reasons for use. Multinomial regression evaluated the association between sample characteristics and class membership. RESULTS: Overall, relaxation had the highest probability of being the most important reason for use (14.8%), followed by harm reduction (13.2%), and flavors (10.3%). LCA identified five distinct classes, based on top reasons for use: 1. cessation (cigarette cessation [20.2%]; n = 80); 2. dependence (relaxation [20.5%] and unable to quit [19.2%]; n = 21); 3. relaxation (relaxation [20.6%]; n = 66); 4. socializing (socializing [22.2%]; n = 27); and 5. variable (boredom [10.5%] and acceptability [10.2%]; n = 36). Participants who were older, smoked cigarettes, or vaped more frequently were more likely to belong to the cessation class while those who were younger or more e-cigarette dependent were more likely to belong to the dependence class. CONCLUSIONS: Perceived reasons why young adults vape are highly heterogeneous and dependent on the type of user. Tobacco regulatory efforts targeting distinct types of vapers are needed to minimize the adverse public health impact of vaping without compromising appeal for smoking cessation. IMPLICATIONS: E-cigarette use remains high among young adults, with flavors, cost, and harm reduction (vs. combustible cigarettes) among the mostly commonly reported reasons for use. Yet, little is known about how relatively important these reasons are to the individual. Leveraging a maximum difference task, young adults' reasons for use were evaluated on a common interval scale and groups sharing similar reasons identified. Smoking cessation, dependence, relaxation, socialization, and boredom were respectively the most important reasons for use among five classes of vapers. E-cigarette regulatory policies should consider the distinct reasons for use as to not compromise their appeal for smoking cessation.

RETRACTED: Changes in Tobacco Dependence and Association With Onset and Progression of Use by Product Type From Wave 1 to Wave 3 of the Population Assessment of Tobacco and Health (PATH) Study.

INTRODUCTION: This study examined trajectories of tobacco dependence (TD) in relation to changes in tobacco product use and explored the effects of product-specific adding, switching, or discontinued use on dependence over time. AIMS AND METHODS: Data were analyzed from the first three waves of the Population Assessment of Tobacco and Health (PATH) Study, a nationally representative, longitudinal study of adults and youth in the United States. Data included 9556 Wave 1 (2013/2014) adult current established tobacco users who completed all three interviews and had established use at ≥2 assessments. Groups included cigarettes-only users, e-cigarettes-only users, cigars-only users, hookah-only users, any smokeless-only users, cigarette + e-cigarette dual users, and multiple product users. A validated 16-item scale assessed TD across product users. RESULTS: Wave 1 e-cigarette-only users' who maintained exclusive e-cigarette use increased levels of TD through Wave 3 as did those who added or switched to another product. Wave 1 multiple product users' TD decreased across waves. TD for all other Wave 1 user groups remained about the same. For Wave 1 cigarette-only smokers, switching to another product or moving to a pattern of no established use was associated with lower levels of TD than smokers whose use stayed the same. Movement to no established use of any tobacco product was consistently associated with lower TD for all other product users. CONCLUSIONS: Except for Wave 1 e-cigarette-only users, TD among US tobacco product users was stable over time, with daily users less likely to vary from baseline. IMPLICATIONS: The level of TD among most US tobacco users was stable over the first three waves of the PATH Study and trends in levels of TD were predominantly unrelated to changes in patterns of continued product use. Stable levels of TD suggest a population at persistent risk of health impacts from tobacco. Wave 1 e-cigarette users, including those maintaining exclusive e-cigarette use, experienced increasing levels of TD over time, perhaps because of increases in quantity or frequency of their e-cigarette product use or increasing efficiency of nicotine delivery over time.

Changes in Tobacco Dependence and Association With Onset and Progression of Use by Product Type From Waves 1 to 3 of the Population Assessment of Tobacco and Health (PATH) Study.

INTRODUCTION: This study examined trajectories of tobacco dependence (TD) in relationship to changes in tobacco product use, and explored the effects of product-specific adding, switching, or discontinued use on dependence over time. AIMS AND METHODS: Data were analyzed from the first three waves from the Population Assessment of Tobacco and Health (PATH) Study, a nationally representative, longitudinal study of adults and youth in the United States. Data included 9556 wave 1 (2013-2014) adult current established tobacco users aged 18 or older who completed all three interviews and had established use at ≥2 assessments. Mutually exclusive groups included: users of cigarettes only, e-cigarettes only, cigars only, hookah only, any smokeless only, cigarette + e-cigarette dual users, and other multiple product users. A validated 16-item scale assessed TD across product users. RESULTS: People who used e-cigarettes exclusively at wave 1 had small increases in TD through wave 3. Wave 1 multiple product users' TD decreased across waves. TD for all other wave 1 user groups remained about the same. For wave 1 cigarette only smokers, switching to another product was associated with lower levels of TD than smokers whose use stayed the same. Movement to no established use of any tobacco product was consistently associated with lower TD for all product users. CONCLUSIONS: Except for wave 1 e-cigarette only users (who experienced small increases in TD), TD among U.S. tobacco product users was stable over time, with daily users less likely to vary from baseline. IMPLICATIONS: The level of TD among most U.S. tobacco users was stable over the first three waves of the PATH Study and trends in levels of TD were predominantly unrelated to changes in patterns of continued product use. Stable levels of TD suggest a population at persistent risk of health impacts from tobacco. Wave 1 e-cigarette users experienced small increases in levels of TD over time, perhaps due to increases in quantity or frequency of their e-cigarette use or increasing efficiency of nicotine delivery over time.

Effect of sweet flavouring on the rewarding and reinforcing value of cigarillo use among young adults.

INTRODUCTION: Cigarillos dominate the US cigar market, and young adults largely drive use. While young adults prefer flavoured to non-flavoured cigarillos, especially those flavoured to taste like fruit or other sweets, the factors that underlie this preference have received little attention. We sought to determine if key indicators of abuse liability, the rewarding and reinforcing effects, are greater for sweet versus non-flavoured cigarillos. METHODS: Young adults (18-24 years old) completed three laboratory visits assessing the subjective rewarding value (exposure paradigm), relative reinforcing value (computerised choice task) and absolute reinforcing value (ad libitum cigarillo smoking session) of sweet-flavoured versus non-flavoured cigarillos. General linear regression models were fit with the appropriate family link for each outcome measure. RESULTS: Young adults rated sweet-flavoured cigarillos as more rewarding (estimated marginal mean (EMM) =4.52, 95% CI 4.00 to 5.03) than the non-flavoured cigarillo (EMM=3.31, 95% CI 2.80 to 3.83; B=1.20, 95% CI 0.80 to 1.60, p<0.001). The reinforcing value of sweet-flavoured cigarillos, measured by break point, was higher relative to non-flavoured cigarillos (6.34 out of 10), especially among young adults with a preference for flavoured cigarillos (B=1.94, 95% CI 0.71 to 3.18, p=0.003). Young adults took 1.9 times the number of puffs (35.75 vs 19.95) from sweet-flavoured cigarillos compared with non-flavoured cigarillos (Rate Ratio =1.94, 95% CI 1.30 to 2.90, p<0.001). CONCLUSIONS: Sweet flavouring increases the abuse liability of cigarillos among young adults as reflected in greater liking, motivation to use and actual use. Banning sweet flavouring in cigarillos may diminish their use in young adults.Trial registration number CT.gov (NCT05092919).

Declines in cigarette smoking among US adolescents and young adults: indications of independence from e-cigarette vaping surge.

OBJECTIVE: To compare trends in cigarette smoking and nicotine vaping among US population aged 17-18 years and 18-24 years. METHODS: Regression analyses identified trends in ever and current use of cigarettes and e-cigarettes, using three US representative surveys from 1992 to 2022. RESULTS: From 1997 to 2020, cigarette smoking prevalence among those aged 18-24 years decreased from 29.1% (95% CI 27.4% to 30.7%) to 5.4% (95% CI 3.9% to 6.9%). The decline was highly correlated with a decline in past 30-day smoking among those aged 17-18 years (1997: 36.8% (95% CI 35.6% to 37.9%; 2022: 3.0% (95% CI 1.8% to 4.1%). From 2017 to 2019, both ever-vaping and past 30-day nicotine vaping (11.0% to 25.5%) surged among those 17-18 years, however there was no increase among those aged 18-24 years. Regression models demonstrated that the surge in vaping was independent of the decline in cigarette smoking. In the 24 most populous US states, exclusive vaping did increase among those aged 18-24 years, from 1.7% to 4.0% to equivalent to 40% of the decline in cigarette smoking between 2014-15 and 2018-19. Across these US states, the correlation between the changes in vaping and smoking prevalence was low (r=0.11). In the two US states with >US$1/fluid mL tax on e-cigarettes in 2017, cigarette smoking declined faster than the US average. CONCLUSIONS: Since 1997, a large decline in cigarette smoking occurred in the US population under age 24 years, that was independent of the 2017-19 adolescent surge in past 30-day e-cigarette vaping. Further research is needed to assess whether the 2014-15 to 2018-19 increase in exclusive vaping in those aged 18-24 years is a cohort effect from earlier dependence on e-cigarette vaping as adolescents.

Effects of cigarette package colors and warning labels on marlboro smokers' risk beliefs, product appraisals, and smoking behavior: a randomized trial.

OBJECTIVE: Plain packaging and graphic warning labels are two regulatory strategies that may impact cigarette risk beliefs and reduce consumption, but data are needed to better understand how smokers respond to such regulations. METHODS: Adult, daily, Marlboro non-menthol smokers (Red [n = 141] or Gold [n = 43]) completed a mixed factorial randomized trial. Participants smoked their usual cigarettes during baseline (5-days) and were randomized to receive cigarette packs with a warning label manipulation (graphic vs. text-only). Within each warning label condition, participants completed three within-subjects pack color manipulations (red, gold, plain), each lasting 15 days. Participants were blinded to the fact that all packs contained their usual cigarettes. Mixed-effects models examined between- and within-subject differences on risk beliefs, product perceptions, and smoking behavior. RESULTS: Warning type and package color did not impact cigarette consumption or subjective ratings. However, use increased in all conditions (2.59-3.59 cigarettes per day) relative to baseline. While smokers largely held correct risk beliefs at baseline (Mean = 6.02, SE = 0.17, Range:0-8), the cumulative number of incorrect or uncertain cigarette risk beliefs increased from baseline in all pack color manipulations in the text (IRR range = 1.70-2.16) and graphic (IRR range = 1.31-1.70) warning conditions. Across all pack color periods, those in the graphic (vs. text) warning condition had reduced odds of reporting their study cigarettes as 'safer' than regular cigarettes (OR range = 0.22-0.32). CONCLUSIONS: Pack color modification may increase uncertainty about several key cigarette risk beliefs, though graphic warnings may attenuate these effects. Regulatory agencies could consider supporting policy changes with information campaigns to maximize public knowledge. TRIAL REGISTRATION: November 25, 2014; Registration number: NCT02301351.

The role of IQOS risk perceptions on cigarette smoking behaviours: results from a prospective pilot study.

BACKGROUND: IQOS is a heated tobacco product marketed as an alternative to combustible cigarette smoking. Little is known about cigarette smokers' IQOS health risk perceptions and if these risk perceptions impact IQOS use and cigarette smoking behaviour. METHODS: Adult, daily, non-treatment-seeking cigarette smokers (n=27), naïve to IQOS, were recruited from Philadelphia, Pennsylvania, USA. Participants were introduced to IQOS and then completed measures of risk perceptions. Participants were given an IQOS 2.4 holder, charger and HeatSticks, and asked to switch completely from cigarettes to IQOS for 14 days. The effects of risk perceptions on changes in IQOS use, cigarettes per day (CPD), the substitution of IQOS for cigarettes and motivation to quit smoking were evaluated. RESULTS: Over the 14-day switch period, CPD significantly decreased (B=-0.18, 95% CI=-0.26 to -0.09, p<0.0001), IQOS use significantly increased (B=0.02, 95% CI=0.00 to 0.03, p=0.042), as did the percentage IQOS HeatSticks that replaced CPD (B=0.02, 95% CI=0.01 to 0.03, p=0.005). Participants who perceived IQOS as less risky than cigarettes used fewer IQOS HeatSticks per day. A lower percentage of IQOS HeatStick substitution for cigarettes was observed for participants with higher versus lower risk perceptions (B=-0.14, 95% CI=-0.28 to -0.01, p=0.042). Motivation to quit increased from a mean of 5.53 to 6.79 on the contemplation ladder from baseline to day 14 (B=1.26, 95% CI=0.54 to 1.97, p<0.001). CONCLUSIONS: Smokers reduced their smoking rate and increased motivation to quit smoking while using IQOS. IQOS risk perceptions did not directly account for reductions in smoking, although they may contribute indirectly through increased IQOS use.

Tool to assess appeal-aversion response to graphic warning labels on cigarette packs among US smokers.

INTRODUCTION: Graphic warning labels on cigarette packaging are mandated in 118 countries and are under consideration in the USA. We propose an appeal-aversion assessment tool to help regulators choose among graphic packaging options. METHODS: After familiarisation with different cigarette packaging, adult daily smokers (n=338) from San Diego, California, USA completed a discrete choice appeal-aversion purchasing task and provided information on nicotine dependence and sociodemographics (2017-2019). The conjoint analysis estimated the importance and price utility for product attributes (ie, packaging, price, tobacco origin and quitline number). The price premiums that smokers would be willing to pay to avoid purchasing graphic packaging were calculated. RESULTS: Among purchase determinants, the price was the most important attribute (65.5%), followed by packaging design (27.1%). Compared with blank packaging without marketing, branded industry packs had appeal valuations (US$0.54; 95% CI: US$0.44 to US$0.65), whereas graphic warning packs had aversion valuations that varied with the salience of the image (blindness=-US$2.53, 95% CI: -US$2.76 to -US$2.31; teeth damage=-US$2.90, 95% CI: -US$3.17 to -US$2.63; and gangrenous foot=-US$3.70, 95% CI: -US$4.01 to -US$3.39). The aversion was such that 46.2% of participants were willing to pay a 50+% premium over their current cigarette price to have their branded packs rather than a graphic pack. These appeal-aversion valuations were moderated by sex, income and nicotine dependence (p<0.05). CONCLUSIONS: Smokers indicated a willingness to pay substantial premiums to avoid purchasing graphic packaging. Results suggest that mandating graphic warnings on US cigarette packs would induce price aversion and may deter cigarette purchasing. Price valuations from this appeal-aversion tool could be useful for regulators to differentiate between graphic warning labels.

Development and validation of a short form Children's power of Food Scale.

OBJECTIVE: To develop and validate a shortened form of the Children's Power of Food Scale (C-PFS), which measures anticipated reward from consuming highly palatable foods (i.e., hedonic hunger). Presently, two gaps exist with the C-PFS: the need for a shorter tighter measure, and evidence to support similar item function across populations. METHOD: Ninth grade students (N = 3277; 14.1 ± 0.4 years; 53.5% Female; 47% Hispanic) from 10 Los Angeles high schools completed the C-PFS and other surveys in class. Factor analysis, graded response modeling, and differential item functioning explored the structure of the 15 C-PFS items and identified a reduced set that parsimoniously taps hedonic hunger across the latent continuum and exhibits item-level invariance across sex, race/ethnicity, and weight status. Construct validity was examined via associations of self-reported dietary intake, impulsivity, and body mass index (BMI) to C-PFS scores. RESULTS: Factor analytic models supported a single, primary dimension of hedonic hunger that accounted for 61% of the variance across all 15-items (α = 0.94). Adequate severity, discriminatory ability, and non-overlapping item-difficulty were observed for 11-items, of which 9-items were found to have item-level invariance across demographic and weight status groupings. Poor performing items were removed to create a 9-item scale (C-PFS-9; α = 0.93). Construct validity was demonstrated as higher C-PFS-9 scores were significantly related to greater sweet (ß = 0.32, [95%CI = 0.23, 0.41], p < .001) and fatty food intake (ß = 0.34, [95%CI = 0.26, 0.43], p < .001) and impulsivity resulting from positive (ß = 0.11, [95%CI = 0.02, 0.21], p < .05) and negative mood (ß = 0.36, [95%CI = 0.28, 0.45], p < .001). Females, relative to males, reported higher C-PFS-9 scores (ß = 0.10, [95%CI = 0.02, 0.17], p < .05) and associations with BMI were mixed. CONCLUSION: The C-PFS-9 possesses excellent psychometric properties and retains the original construct coverage of hedonic hunger without a marked decrease in information obtained.

Characterizing Polytobacco Use Trajectories and Their Associations With Substance Use and Mental Health Across Mid-Adolescence.

Background: Polytobacco product use is suspected to be common, dynamic across time, and increase risk for adverse behavioral outcomes. We statistically modeled characteristic types of polytobacco use trajectories during mid-adolescence and tested their prospective association with substance use and mental health problems. Methods: Adolescents (N = 3393) in Los Angeles, CA, were surveyed semiannually from 9th to 11th grade. Past 6-month combustible cigarette, e-cigarette, or hookah use (yes/no) over four assessments were analyzed using parallel growth mixture modeling to identify a parsimonious set of polytobacco use trajectories. A tobacco product use trajectory group was used to predict substance use and mental health at the fifth assessment. Results: Three profiles were identified: (1) tobacco nonusers (N = 2291, 67.5%) with the lowest use prevalence (<3%) of all products across all timepoints; (2) polyproduct users (N = 920, 27.1%) with moderate use prevalence of each product (8-35%) that escalated for combustible cigarettes but decreased for e-cigarettes and hookah across time; and (3) chronic polyproduct users (N = 182, 5.4%) with high prevalence of each product use (38-86%) that escalated for combustible cigarettes and e-cigarettes. Nonusers, polyproduct users, and chronic polyproduct users reported successively higher alcohol, marijuana, and illicit drug use and ADHD at the final follow-up, respectively. Both tobacco using groups (vs. nonusers) reported greater odds of depression and anxiety at the final follow-up but did not differ from each other. Conclusions: Adolescent polytobacco use may involve a common moderate risk trajectory and a less common high-risk chronic trajectory. Both trajectories predict substance use and mental health symptomology. Implications: Variation in use and co-use of combustible cigarette, e-cigarette, and hookah use in mid-adolescence can be parsimoniously characterized by a small set common trajectory profiles in which polyproduct use are predominant patterns of tobacco product use, which predict adverse behavioral outcomes. Prevention and policy addressing polytobacco use (relative to single product use) may be optimal tobacco control strategies for youth, which may in turn prevent other forms of substance use and mental health problems.

Associations of ADHD Symptoms With Smoking and Alternative Tobacco Product Use Initiation During Adolescence.

Objective: Recently, use of alternative tobacco products, such as electronic cigarettes (e-cigarettes) and hookah (water-pipe tobacco), has increased among adolescents. It is unknown whether attention-deficit hyperactivity disorder (ADHD) symptoms are associated with initiation of alternative tobacco product use. Methods: Ninth grade high school students who never used any tobacco product at baseline (N = 1,921) participated in a longitudinal survey from 2014 to 2015. Overall symptomatology and inattention (IN) and hyperactivity-impulsivity (HI) ADHD subtypes were assessed at baseline. Past 6-month e-cigarette, hookah, and combustible cigarette use (yes/no) were reported at three semi-annual follow-ups. Repeated measures logistic regression models assessed the association of baseline ADHD symptoms with likelihood of tobacco product initiation across follow-ups. Results: For ADHD main effect estimates, unadjusted odds of reporting e-cigarette, hookah, and combustible cigarette use pooled across follow-up time points were 45%, 33%, and 37% greater, respectively, with each increase in one SD-unit of baseline ADHD symptoms in baseline never-users of tobacco products. ADHD was not associated with hookah or combustible cigarette use after adjusting for other risk factors. After adjustment, e-cigarette use initiation remained associated with overall ADHD (odds ratio, OR [95%confidence interval, 95% CI] = 1.22 [1.04, 1.42]) and HI (OR [95% CI] = 1.26 [1.09, 1.47]) symptoms, but not IN symptoms (OR [95% CI] = 1.13 [0.97, 1.32]). ADHD × Time interactions were not significant, suggesting ADHD increased odds of e-cigarette use initiation but did not alter the shape of use trajectory across follow-up among initiators. Conclusions: Understanding the psychosocial mechanisms underlying the pathway from ADHD to e-cigarette use may advance tobacco product use etiologic theory and prevention practice in the current era in which e-cigarette use is popular among youth.

Association of Digital Media Use With Subsequent Symptoms of Attention-Deficit/Hyperactivity Disorder Among Adolescents.

Importance: Modern digital platforms are easily accessible and intensely stimulating; it is unknown whether frequent use of digital media may be associated with symptoms of attention-deficit/hyperactivity disorder (ADHD). Objective: To determine whether the frequency of using digital media among 15- and 16-year-olds without significant ADHD symptoms is associated with subsequent occurrence of ADHD symptoms during a 24-month follow-up. Design, Setting, and Participants: Longitudinal cohort of students in 10 Los Angeles County, California, high schools recruited through convenience sampling. Baseline and 6-, 12-, 18-, and 24-month follow-up surveys were administered from September 2014 (10th grade) to December 2016 (12th grade). Of 4100 eligible students, 3051 10th-graders (74%) were surveyed at the baseline assessment. Exposures: Self-reported use of 14 different modern digital media activities at a high-frequency rate over the preceding week was defined as many times a day (yes/no) and was summed in a cumulative index (range, 0-14). Main Outcomes and Measures: Self-rated frequency of 18 ADHD symptoms (never/rare, sometimes, often, very often) in the 6 months preceding the survey. The total numbers of 9 inattentive symptoms (range, 0-9) and 9 hyperactive-impulsive symptoms (range, 0-9) that students rated as experiencing often or very often were calculated. Students who had reported experiencing often or very often 6 or more symptoms in either category were classified as being ADHD symptom-positive. Results: Among the 2587 adolescents (63% eligible students; 54.4% girls; mean [SD] age 15.5 years [0.5 years]) who did not have significant symptoms of ADHD at baseline, the median follow-up was 22.6 months (interquartile range [IQR], 21.8-23.0, months). The mean (SD) number of baseline digital media activities used at a high-frequency rate was 3.62 (3.30); 1398 students (54.1%) indicated high frequency of checking social media (95% CI, 52.1%-56.0%), which was the most common media activity. High-frequency engagement in each additional digital media activity at baseline was associated with a significantly higher odds of having symptoms of ADHD across follow-ups (OR, 1.11; 95% CI, 1.06-1.16). This association persisted after covariate adjustment (OR, 1.10; 95% CI, 1.05-1.15). The 495 students who reported no high-frequency media use at baseline had a 4.6% mean rate of having ADHD symptoms across follow-ups vs 9.5% among the 114 who reported 7 high-frequency activities (difference; 4.9%; 95% CI, 2.5%-7.3%) and vs 10.5% among the 51 students who reported 14 high-frequency activities (difference, 5.9%; 95% CI, 2.6%-9.2%). Conclusions and Relevance: Among adolescents followed up over 2 years, there was a statistically significant but modest association between higher frequency of digital media use and subsequent symptoms of ADHD. Further research is needed to determine whether this association is causal.

Association of Anhedonia With Adolescent Smoking Susceptibility and Initiation.

INTRODUCTION: Emerging literature implicates anhedonia-diminished capacity to experience pleasure-as a maintaining factor underlying cigarette smoking in adults. The role of anhedonia in adolescent smoking uptake has largely been uninvestigated, leaving unclear whether anhedonia is associated with smoking initiation and with psychosocial determinants of susceptibility to smoking initiation that could be targeted in prevention. This study examined the association of anhedonia with smoking initiation (ever smoke: yes/no) and factors indicative of susceptibility to smoking initiation among never-smokers (smoking outcome expectancies, curiosity about smoking, and willingness and future intention to initiate smoking). METHODS: Ninth grade students enrolled in high schools in Los Angeles, CA (N = 3299; mean [SD] age = 14.1 [0.42] years) were administered in-classroom surveys of anhedonia, depression, smoking, and other characteristics. RESULTS: For every 1 SD unit increase in anhedonia, there was (1) a 42% increase in odds of smoking initiation in the overall sample (odds ratio [95% CI] = 1.42 [1.30-1.56], p < .0001) and (2) higher scores on each marker of smoking initiation susceptibility in the subsample never-smokers (ßs = .10-.19; ps ≤ .002). The associations remained after adjusting for demographics and major depression symptoms. CONCLUSIONS: By early adolescence: (1) anhedonia is associated with smoking initiation and (2) adolescents with higher (vs. lower) anhedonia who have never tried smoking may be more susceptible to smoking initiation perhaps due to stronger prosmoking intentions or willingness to smoke. Preventive interventions that target anhedonia and smoking-related intentions warrant consideration in interventions aimed at reducing risk of smoking initiation in affectively vulnerable youth. IMPLICATIONS: These data suggest that anhedonia may be useful to incorporate into theoretical models of the emotional determinants of smoking initiation risk and provide impetus for addressing anhedonia in smoking prevention efforts.

Pharmacological, sensorimotor, and expectancy effects on tobacco withdrawal: a preliminary study.

OBJECTIVE: Research designs for parsing the mechanisms underlying tobacco withdrawal are scant. This study introduced a novel research design that simultaneously manipulated three tobacco withdrawal mechanisms: pharmacological (nicotine dissipation), sensorimotor (elimination of the smoking ritual), and expectancy (activation of beliefs regarding the effects of nicotine deprivation), permitting examination of the effects of each mechanism while holding the other two mechanisms constant. METHODS: Following overnight abstinence, 32 regular cigarette smokers were randomized in a 2 (expectancy: told patch contains nicotine versus told placebo patch) × 2 (drug: receive 21-mg transdermal nicotine patch versus receive placebo patch) × 2 (sensorimotor: smoke very low nicotine content cigarettes versus no smoking) full factorial between-subjects design. Participants repeatedly completed measures of craving, affect, and anticipated pleasure from and desire for rewarding experiences, followed by a smoking lapse analog task. RESULTS: Receiving nicotine (versus placebo) increased positive affect and anticipated pleasure from and desire for reward. Expecting nicotine (versus placebo) reduced negative affect and increased smoking delay. Sensorimotor stimulation from smoking (versus no smoking) reduced smoking urge and behavior. CONCLUSION: Results provided initial validation of this novel three-mechanism design. This design can be used in the future to advance understanding and treatment of tobacco withdrawal.

Association of Electronic Cigarette Use With Initiation of Combustible Tobacco Product Smoking in Early Adolescence.

IMPORTANCE: Exposure to nicotine in electronic cigarettes (e-cigarettes) is becoming increasingly common among adolescents who report never having smoked combustible tobacco. OBJECTIVE: To evaluate whether e-cigarette use among 14-year-old adolescents who have never tried combustible tobacco is associated with risk of initiating use of 3 combustible tobacco products (ie, cigarettes, cigars, and hookah). DESIGN, SETTING, AND PARTICIPANTS: Longitudinal repeated assessment of a school-based cohort at baseline (fall 2013, 9th grade, mean age = 14.1 years) and at a 6-month follow-up (spring 2014, 9th grade) and a 12-month follow-up (fall 2014, 10th grade). Ten public high schools in Los Angeles, California, were recruited through convenience sampling. Participants were students who reported never using combustible tobacco at baseline and completed follow-up assessments at 6 or 12 months (N = 2530). At each time point, students completed self-report surveys during in-classroom data collections. EXPOSURE: Student self-report of whether he or she ever used e-cigarettes (yes or no) at baseline. MAIN OUTCOMES AND MEASURES: Six- and 12-month follow-up reports on use of any of the following tobacco products within the prior 6 months: (1) any combustible tobacco product (yes or no); (2) combustible cigarettes (yes or no), (3) cigars (yes or no); (4) hookah (yes or no); and (5) number of combustible tobacco products (range: 0-3). RESULTS: Past 6-month use of any combustible tobacco product was more frequent in baseline e-cigarette ever users (n = 222) than never users (n = 2308) at the 6-month follow-up (30.7% vs 8.1%, respectively; difference between groups in prevalence rates, 22.7% [95% CI, 16.4%-28.9%]) and at the 12-month follow-up (25.2% vs 9.3%, respectively; difference between groups, 15.9% [95% CI, 10.0%-21.8%]). Baseline e-cigarette use was associated with greater likelihood of use of any combustible tobacco product averaged across the 2 follow-up periods in the unadjusted analyses (odds ratio [OR], 4.27 [95% CI, 3.19-5.71]) and in the analyses adjusted for sociodemographic, environmental, and intrapersonal risk factors for smoking (OR, 2.73 [95% CI, 2.00-3.73]). Product-specific analyses showed that baseline e-cigarette use was positively associated with combustible cigarette (OR, 2.65 [95% CI, 1.73-4.05]), cigar (OR, 4.85 [95% CI, 3.38-6.96]), and hookah (OR, 3.25 [95% CI, 2.29-4.62]) use and with the number of different combustible products used (OR, 4.26 [95% CI, 3.16-5.74]) averaged across the 2 follow-up periods. CONCLUSIONS AND RELEVANCE: Among high school students in Los Angeles, those who had ever used e-cigarettes at baseline compared with nonusers were more likely to report initiation of combustible tobacco use over the next year. Further research is needed to understand whether this association may be causal.

Identification and origin of N-linked ß-D-N-acetylglucosamine monosaccharide modifications on Arabidopsis proteins.

Many plant proteins are modified with N-linked oligosaccharides at asparagine-X-serine/threonine sites during transit through the endoplasmic reticulum and the Golgi. We have identified a number of Arabidopsis (Arabidopsis thaliana) proteins with modifications consisting of an N-linked N-acetyl-D-glucosamine monosaccharide (N-GlcNAc). Electron transfer dissociation mass spectrometry analysis of peptides bearing this modification mapped the modification to asparagine-X-serine/threonine sites on proteins that are predicted to transit through the endoplasmic reticulum and Golgi. A mass labeling method was developed and used to study N-GlcNAc modification of two thioglucoside glucohydrolases (myrosinases), TGG1 and TGG2 (for thioglucoside glucohydrolase). These myrosinases are also modified with high-mannose (Man)-type glycans. We found that N-GlcNAc and high-Man-type glycans can occur at the same site. It has been hypothesized that N-GlcNAc modifications are generated when endo-ß-N-acetylglucosaminidase (ENGase) cleaves N-linked glycans. We examined the effects of mutations affecting the two known Arabidopsis ENGases on N-GlcNAc modification of myrosinase and found that modification of TGG2 was greatly reduced in one of the single mutants and absent in the double mutant. Surprisingly, N-GlcNAc modification of TGG1 was not affected in any of the mutants. These data support the hypothesis that ENGases hydrolyze high-Man glycans to produce some of the N-GlcNAc modifications but also suggest that some N-GlcNAc modifications are generated by another mechanism. Since N-GlcNAc modification was detected at only one site on each myrosinase, the production of the N-GlcNAc modification may be regulated.

Non-ATG-initiated translation directed by microsatellite expansions.

Trinucleotide expansions cause disease by both protein- and RNA-mediated mechanisms. Unexpectedly, we discovered that CAG expansion constructs express homopolymeric polyglutamine, polyalanine, and polyserine proteins in the absence of an ATG start codon. This repeat-associated non-ATG translation (RAN translation) occurs across long, hairpin-forming repeats in transfected cells or when expansion constructs are integrated into the genome in lentiviral-transduced cells and brains. Additionally, we show that RAN translation across human spinocerebellar ataxia type 8 (SCA8) and myotonic dystrophy type 1 (DM1) CAG expansion transcripts results in the accumulation of SCA8 polyalanine and DM1 polyglutamine expansion proteins in previously established SCA8 and DM1 mouse models and human tissue. These results have implications for understanding fundamental mechanisms of gene expression. Moreover, these toxic, unexpected, homopolymeric proteins now should be considered in pathogenic models of microsatellite disorders.

The interacting effects of depression symptoms and sweet flavoring on the rewarding and reinforcing value of cigarillo use among young adults.

Background: Young adults 18-24 years old have the highest prevalence of cigarillo use, exposing young adults to comparable or higher nicotine levels and many of the same toxicants as combustible cigarettes. Identifying individual and product characteristics that increase the potential for persistent use is warranted. We sought to examine the interacting effects of depression symptoms and sweet flavoring on the rewarding and reinforcing value of cigarillo use. Methods: 86 young adults (18-24 years old, 73.3 % male, 38.4 % White, 33.7 % Black, and 27.9 % Other) completed three laboratory visits assessing the subjective rewarding value (exposure paradigm), relative reinforcing value (computerized choice task), and absolute reinforcing value (ad libitum cigarillo smoking session) of sweet-flavored versus non-flavored cigarillos. Depression symptoms were measured with the 20-item Center for Epidemiologic Studies of Depression Scale and treated as a continuous variable. Results: General linear models with the appropriate family link tested differences in depressive symptomology for each outcome. Irrespective of flavor, greater cigarillo subjective reward was reported across increasing depressive symptomology (B=.0.03 [95%CI=0.00, 0.05], p=.017). Across symptom levels, no significant differences were observed in the subjective reward and relative and absolute reinforcing values of sweet-flavored versus non-flavored cigarillos (p's >.05). Conclusions: Young adults with elevated depression find cigarillos more rewarding but not more reinforcing. They are not more vulnerable than young adults with lower symptom levels to sweet cigarillo flavoring. Public health prevention campaigns and tobacco product regulations aimed at preventing the initiation and escalation of young adult cigarillo use may impact young adults broadly.

Effects of intranasal oxytocin on cigarette withdrawal and smoking in the laboratory: Differences by sex and social functioning traits.

Intranasal oxytocin (INOT) has received attention as a treatment for substance use disorders including tobacco dependence. However, it is unclear whether INOT-related effects differ by sex and social functioning traits. This study examined the influence of sex and two trait social functioning measures (hostility and rejection sensitivity) on INOT effects on abstinence-related subjective measures and smoking lapse. Adults who smoked cigarettes daily (N = 64; 21-40 years; 39% female) completed trait hostility and rejection sensitivity surveys at baseline followed by three experimental sessions following 12-hr smoking abstinence. Each session, participants received a single INOT dose (placebo, 20, 40 international units [IU]) in counterbalanced order, completed withdrawal, smoking urges and affect questionnaires, and a smoking lapse analog task. Interactive effects between INOT and sex, hostility, or rejection sensitivity on all outcomes were analyzed. INOT produced differential effects as a function of sex, trait hostility, and rejection sensitivity. The 20 IU dose worsened abstinence-related subjective effects for individuals with high trait hostility. Both INOT doses decreased smoking urges for high rejection sensitivity, and the 20 IU dose increased smoking urges for low rejection sensitivity. INOT increased withdrawal symptoms, smoking urges, and feelings of anger in females but not males. INOT did not improve withdrawal symptoms during abstinence and did not affect smoking lapse. While INOT produced some beneficial effects for a subset of participants with high rejection sensitivity, it worsened abstinence-related symptoms for others. Our results suggest that sex and social functioning should be considered when examining the therapeutic potential of INOT for smoking cessation in future research. (PsycInfo Database Record (c) 2024 APA, all rights reserved).