Longitudinal Transitions Between Use of Combustible, Noncombustible, and Multiple Cannabis Products From Adolescence to Young Adulthood and Intersections With Nicotine Use.

Understanding transitions across use of different types of cannabis products and multiple cannabis products and how they intersect with nicotine use in young people can inform etiology and prevention. In this study, we examined transitions across use of combustible and noncombustible forms of cannabis and multiple types of cannabis from adolescence to young adulthood and the role of nicotine use in transitions. In a Southern California longitudinal cohort study (n = 3,298; baseline mean age = 16.1 (standard deviation, 0.4) years) with 9 semiannual survey waves (2015-2021), we used Markov multistate transition modeling to estimate short-term (2-wave) and long-term (9-wave) probabilities of transition across 5 cannabis use states: never use of any product, prior use with no past-6-month (P6M) use of any product, and P6M use of exclusively noncombustible products, exclusively combustible products, and multiple (noncombustible + combustible) products. Sizable transition probabilities from prior and exclusive P6M noncombustible or combustible cannabis use to P6M poly-cannabis-product use were observed in short-term (10.7%-38.9%) and long-term (43.4%-43.8%) analyses. P6M nicotine use increased risk of transitioning from never and prior use to exclusive P6M noncombustible and combustible cannabis use. Cannabis use in any form, even temporary use, during midadolescence may often be followed by poly-cannabis-product use. Nicotine use may amplify the probability of future cannabis use onset or recurrence.

Recall of Flavor at First E-cigarette Use and its Association with E-cigarette Progression: The Mediating Effects of First Sensory Experience.

OBJECTIVE: To test whether the association between flavor at first vape and continued use is mediated through subjective experience at first vape. STUDY DESIGN: In a 2020 cross-sectional survey, 955 young adult ever-vapers recalled their first flavor vaped, subjective experiences at first use, current vaping behavior, nicotine dependence, and quit attempts. A latent class model grouped first-use subjective experiences into classes. Two-part negative binomial hurdle models for each vaping behavior evaluated whether the association of first flavor used with vaping outcomes was mediated by positive experience. RESULTS: Four latent classes (positive, positive and negative, negative, and minimal experience) were further reduced to "any positive experience" (only positive, positive and negative) vs "no positive experience" (negative or minimal). Class membership mediated the association of first flavor used (mint/menthol/ice [ie, "cooling"] or sweet vs other) with each vaping outcome. For example, cooling flavor (vs. other) was associated with positive class membership (OR=3.5; 95%CI:1.5,8.1), which was then associated with any past 30-day vaping (OR=3.9; 95%CI:2.7,5.8) and greater number of vaping days among current vapers (RR=1.9; 95%CI:1.3,2.7) in the two-part hurdle model. Similar results were observed for nicotine dependence and quit attempts, and for sweet (vs. other) flavor for any dependence or quit attempts, but not number of dependence symptoms or quit attempts. CONCLUSIONS: Use of a cooling or sweet flavor at first use was associated with having a positive first vaping sensory experience, and then greater likelihood as a young adult of reporting past 30-day vaping, more vaping days, and greater risk for nicotine dependence, suggesting a key mediating role of first use experience.

Young Adults' Exposure to and Engagement With Tobacco-Related Social Media Content and Subsequent Tobacco Use.

INTRODUCTION: Nicotine/tobacco social media content may increase young people's risk for use. This study examined prospective associations between exposure to and engagement with nicotine/tobacco-related social media content and nicotine/tobacco use among young adults. AIMS AND METHODS: Young adults (N = 2080) originally recruited from Southern California high schools for a prospective cohort study reported frequency of viewing and posting nicotine/tobacco content on four social media platforms (Facebook, Instagram, Twitter, and YouTube). Participants also reported frequency of seeing nicotine/tobacco posts from friends, seeing nicotine/tobacco posts from influencers or celebrities, and liking nicotine/tobacco posts. Within subsamples of nicotine/tobacco never users (n = 794), past users (n = 897) and current users (n = 389), analyses examined associations of baseline (May-October 2020) social media content exposure and engagement with follow-up (January-June 2021) tobacco use initiation (among never users), resumption (among past users), and continuation (among current users), adjusting for sociodemographic and socioenvironmental characteristics. RESULTS: Never users who saw nicotine/tobacco posts from friends (Adjusted Odds Ratio [AOR] = 2.91 [95% Confidence Interval [CI]: 1.46, 5.82], p = .002) or from celebrities or influencers (AOR = 2.77 [1.32, 5.84], p = .007) were significantly more likely to initiate nicotine/tobacco use than their peers. Among past users, posting nicotine/tobacco content at baseline was associated with use resumption (AOR = 1.77 [1.12, 2.80], p = .014). Content exposure and engagement were not associated with nicotine/tobacco use continuation among current users (p-values > .05). CONCLUSIONS: Seeing nicotine/tobacco posts from friends, influencers, or celebrities was associated with greater odds of tobacco use initiation, but not resumption or continuation, 6 months later. Young adults with past nicotine/tobacco use who post about nicotine/tobacco may be at elevated risk for resuming use. IMPLICATIONS: Young adults with exposure to nicotine/tobacco social media content were more likely than their peers to initiate nicotine/tobacco use 6 months later. Past nicotine/tobacco users who reported posting about nicotine/tobacco on social media at baseline were more likely than their peers to resume nicotine/tobacco use. Among young adults with current nicotine/tobacco use at baseline, social media activity did not predict odds of nicotine/tobacco use continuation at follow-up. Nicotine/tobacco content on social media should be restricted to reduce young people's chances of nicotine/tobacco use initiation or resumption.

US adolescents' response to nicotine warning labels in influencer e-cigarette marketing social media posts: a survey-based randomised between-subject experiment.

BACKGROUND: E-cigarette promotional posts with misleading nicotine warning labels on social media may lower adolescents' risk perceptions of e-cigarettes. A between-subject experiment assessed effects of influencers' e-cigarette promotional posts with different nicotine warning labels on adolescents' e-cigarette harm perceptions, susceptibility to e-cigarette use and perceptions of influencer credibility. METHODS: In 2022, adolescents (N=1864, Mage=17 (SD=0.6)) were randomised to view six images and videos featuring influencers promoting e-cigarettes in one of five experimental conditions: two conditions with a 'tobacco-free nicotine' warning label (placed on an e-cigarette in the post or at the top of the post), two conditions with the US Food and Drug Administration (FDA) nicotine warning label (on an e-cigarette in the post or at the top of the post (control)) and one no-label condition. Participants rated influencers' credibility (eg, honesty). Harm perceptions of, and susceptibility to use, e-cigarettes were then assessed. RESULTS: Participants who viewed posts with the FDA warning label at the top of the post perceived influencers as more honest, trustworthy and informed than in all the other conditions. E-cigarette never-users who viewed posts with a 'tobacco-free nicotine' warning label pictured on an e-cigarette (compared with the FDA label at the top of a post) were more likely to report susceptibility to e-cigarette use (adjusted OR 1.79, 95% CI 1.17 to 2.73). CONCLUSIONS: Alterations of the required nicotine warning labels can make them less effective in deterring e-cigarette use behaviour. Tobacco control authorities could increase enforcement of the FDA-required nicotine warning labels and harness influencers for antitobacco messaging.

Effects of exposure to snus marketing with versus without modified risk tobacco product claims on snus use intention and perceived harm among young adults.

BACKGROUND: We tested whether snus marketing with modified risk tobacco product (MRTP) claims: (a) promotes accurate knowledge about snus's health effects in young adults and (b) encourages use intentions in only those who use combustible tobacco without attracting other young adult populations. METHODS: A randomised between-subjects experiment was embedded in a 2020 web survey of participants from Los Angeles (aged 19-23 years). Participants viewed mass-marketed snus advertising materials with (n=1212) vs without (n=1225) US Food and Drug Administration-authorised MRTP claims. After advertising exposure, snus use intention and perceptions of snus harms relative to cigarettes or e-cigarettes were measured. RESULTS: Advertisements with versus without MRTP claims did not affect snus use intention (18.0% vs 19.4%) but produced a higher prevalence of perceptions that snus was less harmful than cigarettes (12.6% vs 9.1%; p=0.007) and e-cigarettes (8.0% vs 5.8%; p=0.04). MRTP claim exposure effects did not differ by past 30-day e-cigarette or combustible tobacco use. Snus use intentions after marketing exposure, collapsed across MRTP claim conditions, were higher in those who did versus did not report past 30-day use of e-cigarettes (38.4% vs 14.3%; adjusted OR (95% CI) 2.95 (2.28 to 3.81); p<0.001) or combustible tobacco (44.0% vs 16.2%; adjusted OR (95% CI) 2.26 (1.62 to 3.16); p<0.001). CONCLUSION: Although some young adults who vape or smoke may have snus use intentions, snus MRTP claims might not affect young adults' snus use intentions, regardless of whether they vape/smoke. MRTP claims might modestly increase the accuracy of perceived harms of snus relative to cigarettes while also slightly causing unsubstantiated perceptions of lower harm than e-cigarettes.

Adolescents' perceptions of substance use messaging in the age of social media: resolving cognitive dissonance.

This study interviewed adolescents about their exposure to and perceptions of substance-related social media content and substance use prevention messages. Participants (analytic sample N = 30, age 14-18 years, in CA, USA, 40% male) were recruited from Instagram and Facebook for online semi-structured interviews. An interview transcript coding guide was developed based on the interview questions and emerging themes. Most (27/30) participants reported exposure to peers using substances on social media through posts made on personal accounts. All peer posts portrayed substance use in a positive light. Most participants reported exposure to formal prevention messages on social media (i.e. public service announcements) (19/30) and in schools (i.e. drug education) (21/30; 70.0%) teaching the negative consequences of substance use. Responses to the differences between peer posts and prevention messages included dismissing prevention messages (7/30), believing that their peers were more credible (4/30), desiring comprehensive substance information (3/30) and believing that the no-use message was ineffective for at-risk youth (4/30). Messages shared by peers online significantly contrasted with prevention messages (i.e. public service announcements and drug education). This difference appeared to undermine prevention message credibility. Balanced prevention messages acknowledging the spectrum of risk and reward when using different substances may reduce dissonance and increase engagement.

Characteristics of Adolescents' and Young Adults' Exposure to and Engagement with Nicotine and Tobacco Product Content on Social Media.

To inform policy and messaging, this study examined characteristics of adolescents' and young adults' (AYAs') exposure to and engagement with nicotine and tobacco product (NTP) social media (SM) content. In this cross-sectional survey study, AYAs aged 13-26 (N=1,163) reported current NTP use, SM use frequency, and exposure to and engagement with SM content promoting and opposing NTP use (i.e. frequency, source[s], format[s], platform[s]). Participants who used NTPs (vs. did not use) were more likely to report having seen NTP content (p-values<.001). Prevalent sources were companies/brands (46.6%) and influencers (44.4%); prevalent formats were video (65.4%) and image (50.7%). Exposure to content promoting NTP use was prevalent on several popular platforms (e.g. TikTok, Instagram, Snapchat); exposure to content opposing NTP use was most prevalent on YouTube (75.8%). Among those reporting content engagement (i.e. liking, commenting on, or sharing NTP content; 34.6%), 57.2% engaged with influencer content. Participants reported engaging with content promoting and opposing NTP use on popular platforms (e.g. TikTok, Instagram, YouTube). Participants with (versus without) current NTP use were significantly more likely to use most SM platforms and to report NTP content exposure and engagement (p-values<.05). Results suggest that NTP education messaging and enforcement of platforms' content restrictions are needed.

Alcohol Use and Life Stressors During the COVID-19 Pandemic: A Longitudinal Study of Young Adults.

Objective: To estimate the extent to which drinking to cope with the COVID-19 pandemic and experiencing pandemic-related life stressors are associated with alcohol use escalation among young adults. Methods: Respondents in Los Angeles, CA, USA (N=2,130) completed prospective cohort study surveys before (baseline; October 2018-November 2019; mean age: 19.7[SD=0.4) and during (follow-up; May-August 2020) the COVID-19 outbreak. Past 30-day drinking days and number of drinks per drinking day were assessed from baseline to follow-up. At follow-up, participants reported drinking to cope with social isolation and pandemic-related stressors. Results: Pandemic-related stressor prevalence ranged from 5.5% (evicted/lost home) to 72.6% (worried about education) and 27.1% drank to cope with social isolation during the pandemic. Respondents who did (vs. did not) report pandemic-related coping drinking were more likely to increase past 30-day drinking days and drinks per drinking day from baseline to follow-up after adjustment for possible confounders. Employment loss/reduction, financial problems, and perceived likelihood of contracting COVID-19 or handling the pandemic poorly were each associated with increases in drinking days or drinks per drinking day. Conclusions: Experiencing certain life stressors and drinking to cope with social isolation may be associated with drinking escalation among young adults during the COVID-19 pandemic.

Prevalence of and disparities in adolescents' susceptibility to novel oral nicotine products marketed as "tobacco-free".

Non-therapeutic, novel oral nicotine products are convenient, discreet to use, and flavored, with increasing sales in the United States. It is unclear whether these products appeal predominantly to adolescents already susceptible to inhalable nicotine products, or whether they attract adolescents who would not otherwise use nicotine. This study examined prevalence and correlates of susceptibility to inhalable and oral nicotine product use among adolescents. Ninth- and tenth-grade students from Southern California who had never used any nicotine product (N = 3129) completed an online survey in Fall 2021 assessing susceptibility to inhalable (i.e., cigarettes, e-cigarettes) and oral (e.g., pouches, gum, gummies) nicotine products. Multinomial logistic regression analyses estimated associations of demographic characteristics with odds of susceptibility to oral, inhalable, or both products. Susceptibility was highest for e-cigarettes (19.7%), followed by cigarettes (15.0%) and nicotine gum, lozenges, tablets and/or gummies (15.0%), and nicotine pouches (8.7%). Dual susceptibility to oral and inhalable products (vs. neither product type) was higher in cisgender female and non-cisgender (vs. cisgender male) adolescents (odds ratios [ORs] = 1.36-2.02; ps < 0.05). Hispanic adolescents (vs. Asian) were more susceptible to both products (OR = 1.47; p < .05). Lower-socioeconomic status (SES) and sexual minority adolescents were more susceptible to oral (ORs = 1.76-1.87; ps < 0.05) and both products (ORs = 1.32-1.88; ps < 0.05), compared to higher-SES and heterosexual adolescents. Adolescents in Southern California may be more susceptible to e-cigarettes than other nicotine/tobacco products. However, appreciable numbers may be susceptible to oral nicotine products, including some youth who might not otherwise use nicotine and youth from populations historically impacted by tobacco-related health disparities.

An Analysis of Twitter Posts About the U.S. Food and Drug Administration's Menthol Ban.

INTRODUCTION: Although the U.S. Food and Drug Administration (FDA) banned characterizing flavors in cigarettes in 2009, this initial ban exempted menthol. After examining numerous reports on the adverse health effects of menthol cigarettes, the FDA proposed a menthol ban in April 2022. This study analyzed Twitter data to describe public reaction to this announcement. AIMS AND METHODS: Posts containing the word "menthol" and/or "#menthol" were collected from April 21, 2022 to May 5, 2022 from Twitter's Streaming Application Programming Interface (API). A random sampling procedure supplied 1041 tweets for analysis. Following an inductive approach to content analysis, posts were classified into one or more of 11 themes. RESULTS: Posts discussed the FDA announcement (n = 153, 14.7%), racial discrimination (n = 101, 9.7%), distrust in government (n = 67, 6.4%), inconsistencies between policies (n = 52, 5.0%), public health benefits (n = 42, 4%), freedom of choice (n = 22, 2.1%), and health equity (n = 21, 2.0%). Posts contained misinformation (n = 20, 1.9%), and discussed the potential for illicit markets (n = 18, 1.7%) and the need for cessation support (n = 4, 0.4%). 541 (52.0%) tweets did not fit into any of the prescribed themes. CONCLUSIONS: Twitter posts with the word "menthol" commonly discussed distrust in government and mentioned racial discrimination. Findings demonstrated the possibility of near real-time Twitter monitoring of public opinion on a menthol ban. These data may be valuable for designing tobacco control health communication campaigns in the future. IMPLICATIONS: The U.S. FDA proposed a ban on menthol cigarettes in April 2022. This study's content analyzed Twitter posts over a 2-week period to understand the public's response to the proposed menthol ban. Twitter posts with the word "menthol" often discussed distrust in government and mentioned racial discrimination. Findings demonstrated the possibility of near real-time Twitter monitoring of public opinion of regulatory action. Findings underscore the need to educate the public about the potential health benefits of banning menthol from cigarettes, particularly for populations that experience tobacco-related health disparities.

Dose-response effects of two nicotine salt formulations on electronic cigarette appeal and sensory attributes.

OBJECTIVES: Various organic acids are used to create nicotine salt formulations, which may improve the appeal and sensory experience of vaping electronic cigarettes (e-cigarettes). This clinical experiment examined the effects of partially and highly protonated forms of two nicotine salt formulations (nicotine lactate and benzoate) versus free-base (no acid additive) on the appeal and sensory attributes of e-cigarettes. METHODS: Current adult tobacco product users (n=116) participated in an online remote double-blind within-subject randomised experiment involving standardised self-administration of e-cigarette solutions varying in nicotine formulation (free-base, 50% nicotine lactate -1:2 lactic acid to nicotine molar ratio, 100% nicotine lactate - 1:1 ratio, 50% nicotine benzoate and 100% nicotine benzoate). Each formulation had equivalent nicotine concentrations (27.0-33.0 mg/mL) and was administered in four flavours in a pod-style device. After each administration, participants rated appeal (liking, disliking and willingness to use again) and sensory attributes (0-100 scale). RESULTS: Compared with free-base nicotine, 50% and 100% nicotine lactate and benzoate yielded higher appeal, smoothness and sweetness and lower harshness and bitterness. Dose-response analyses found 100% vs 50% nicotine salt improved appeal, smoothness, bitterness and harshness for nicotine lactate and sweetness, smoothness and harshness for nicotine benzoate. Solutions with higher pH were associated with worse appeal and sensory attributes across nicotine formulations. Nicotine formulation effects did not differ by tobacco use status and flavours. CONCLUSION: Restricting benzoic acid or lactic acid additives or setting minimal pHs in e-cigarettes merits consideration in regulations designed to reduce vaping among populations deterred from using e-cigarettes with aversive sensory properties. TRIAL REGISTRATION NUMBER: This study was registered under ClinicalTrials.gov Identifier: NCT03742817 under the title 'Effects of e-Cigarettes on Perceptions and Behavior'.

Effects of flavour and modified risk claims on nicotine pouch perceptions and use intentions among young adults who use inhalable nicotine and tobacco products: a randomised controlled trial.

BACKGROUND: Availability of flavours and potential modified risk tobacco product (MRTP) claims may influence young adults' (YAs') perceptions of and intentions to use nicotine pouches ('pouches'). METHODS: YAs aged 21-34 years (N=47, M age=24.5, SD=3.1) with past-month nicotine/tobacco use (10.6% cigarette-only, 51.1% e-cigarette-only, 38.3% dual use) and no intention to quit were randomised to self-administer four Zyn 3 mg nicotine pouches in a 4 (flavour; within-subjects: smooth, mint, menthol, citrus) × 2 (MRTP claim on packaging; between subjects: present or absent) mixed-factorial design. After self-administering each pouch, participants reported appeal, use intentions and perceived harm compared with cigarettes and e-cigarettes. Three mixed-factorial analysis of variances (ANOVAs) examined main and interactive effects of flavour and MRTP claim on appeal, use intentions and comparative harm perceptions. RESULTS: Mint (M=55.9, SD=26.4), menthol (M=49.7, SD=26.8) and citrus (M=46.6, SD=24.8) flavours were significantly more appealing than smooth (M=37.6, SD=25.4; p<0.001). MRTP claim did not significantly affect product appeal (p=0.376). Use intentions were greater for mint (M=2.6, SD=1.3) and menthol (M=2.0, SD=1.1) flavours than smooth (M=1.8, SD=1.0; p=0.002). Flavour did not affect comparative harm perceptions (p values>0.418). MRTP claims increased use intention (p=0.032) and perceptions of pouches as less harmful than cigarettes (p=0.011), but did not affect perceived harm relative to e-cigarettes (p=0.142). Flavour × MRTP claim interactions were not significant. CONCLUSIONS: Flavoured (vs smooth) pouches were more appealing to YAs. MRTP claims reduced perceived harm of pouches compared with cigarettes; however, intentions to switch were low. To protect YAs' health, regulatory restrictions could target flavours and MRTP claims.

Alternative reproductive tactics of unflanged and flanged male orangutans revisited.

In many slowly developing mammal species, males reach sexual maturity well before they develop secondary sexual characteristics. Sexually mature male orangutans have exceptionally long periods of developmental arrest. The two male morphs have been associated with behavioral alternative reproductive tactics, but this interpretation is based on cross-sectional analyses predominantly of Northwest Sumatran populations. Here we present the first longitudinal analyses of behavioral changes of 10 adult males that have been observed in both unflanged and flanged morph. We also analyzed long-term behavioral data on an additional 143 individually identified males from two study sites, Suaq (Sumatra, Pongo abelii) and Tuanan (Borneo, Pongo pygmaeus wurmbii), to assess male mating tactics cross-sectionally in relation to population, male morph (unflanged and flanged), and other socio-ecological factors. Both our longitudinal and cross-sectional results confirm and refine previous cross-sectional accounts of the differences in mating tactics between the unflanged and the flanged male morphs. In the unflanged morph, males exhibit higher sociability, particularly with females, and higher rates of both copulation and sexual coercion than in the flanged morph. Based on our results and those of previous studies showing that females prefer flanged males, and that flanged males have higher reproductive success, we conclude that unflanged males face a trade-off between avoiding male-male contest competition and gaining mating access to females, and thus follow a "best-of-a-bad-job" mating strategy.

Young Adults' Perceptions of and Intentions to Use Nicotine and Cannabis Vaporizers in Response to e-Cigarette or Vaping-Associated Lung Injury Instagram Posts: Experimental Study.

BACKGROUND: Inhaling aerosolized nicotine and cannabis (colloquially called "vaping") is prevalent among young adults. Instagram influencers often promote both nicotine and cannabis vaporizer products. However, Instagram posts discouraging the use of both products received national media attention during the 2019 outbreak of e-cigarette or vaping-associated lung injury (EVALI). OBJECTIVE: This experiment tested the impact of viewing Instagram posts about EVALI, varying in image and text valence, on young adults' perceived harmfulness of nicotine and cannabis products, perceived risk of nicotine and cannabis vaporizer use, and intentions to use nicotine and cannabis vaporizers in the future. METHODS: Participants (N=1229) aged 18-25 (mean 21.40, SD 2.22) years were recruited through Qualtrics Research Services, oversampling for ever-use of nicotine or cannabis vaporizers (618/1229, 50.3%). Participants were randomly assigned to view Instagram posts from young people portraying their experiences of EVALI in a 2 (image valence: positive or negative) × 2 (text valence: positive or negative) between-subjects experiment. Positive images were attractive and aesthetically pleasing selfies. The positive text was supportive and uplifting regarding quitting the use of vaporized products. Negative images and text were graphic and fear inducing. After viewing 3 posts, participants reported the perceived harmfulness of nicotine and cannabis products, the perceived risk of nicotine and cannabis vaporizer use, and intentions to use nicotine and cannabis vaporizers in the future. Ordinal logistic regression models assessed the main effects and interactions of image and text valence on perceived harmfulness and risk. Binary logistic regression models assessed the main effects and interactions of image and text valence on intentions to use nicotine and cannabis vaporizers. Analyses were adjusted for product use history. RESULTS: Compared to viewing positive images, viewing negative images resulted in significantly greater perceived harm of nicotine (P=.02 for disposable pod-based vaporizers and P=.04 for other e-cigarette "mods" devices) and cannabis vaporized products (P=.01), greater perceived risk of nicotine vaporizers (P<.01), and lower odds of intentions to use nicotine (P=.02) but not cannabis (P=.43) vaporizers in the future. There were no significant main effects of text valence on perceived harm, perceived risk, and intentions to use nicotine and cannabis vaporized products. No significant interaction effects of image and text valence were found. CONCLUSIONS: Negative imagery in Instagram posts about EVALI may convey the risks of vaporized product use and discourage young adults from this behavior, regardless of the valence of the post's text. Public health messaging regarding EVALI on Instagram should emphasize the risk of cannabis vaporizer use, as young adults may otherwise believe that only nicotine vaporizer use increases their risk for EVALI.

Nicotine delivery and cigarette equivalents from vaping a JUULpod.

With patented nicotine salt technology, JUUL dominates the e-cigarette market. We reviewed studies of JUUL's nicotine pharmacokinetic profile and studies quantifying nicotine in a JUULpod, emitted in the aerosol and absorbed by users. Examined in eight studies, JUUL's peak nicotine levels were half to three-quarters that of a combustible cigarette in industry-conducted studies with JUUL-naïve users, while comparable to or greater than combustible cigarettes in independent studies of experienced e-cigarette users. JUUL Labs reports each 5% (nicotine-by-weight) cartridge contains approximately 40 mg nicotine per pod and is 'approximately equivalent to about 1 pack of cigarettes.' In five independent studies, nicotine in the liquid in a JUULpod ranged from 39.3 to 48.3 mg. Seven studies measured nicotine delivery via vaping-machine generated aerosols, varying in puffing regimes and equipment. One study estimated 68% transfer efficiency to the aerosol, measuring 28.8 mg nicotine per JUULpod. The other studies reported nicotine values ranging from 72 to 164 µg/puff. At 200 puffs, this is 14.4-32.8 mg of nicotine per pod with equivalence to 13-30 cigarettes. A study measuring nicotine levels in JUUL users during a 5-day controlled switch found equivalence to 18 cigarettes. One JUULpod appears capable of delivering the nicotine equivalent to smoking about a pack of cigarettes, with variability. In JUUL-naïve smokers, JUUL's nicotine boost was lower than that of combustible cigarettes; while in experienced users, JUUL was comparable. Minimising harshness and adaptive to user experience, JUUL's design facilitates initiation to a high nicotine, and ultimately, highly addictive vaping product.

Tobacco product use and susceptibility to use among sexual minority and heterosexual adolescents.

Sexual identity is associated with tobacco use in adults. We examined tobacco use and susceptibility to use by sexual identity in adolescents. Data were collected in February 2019 via Qualtrics research participant panels. Data analyses were performed in June 2019 and updated in October 2020. Respondents aged 13-17 reported sexual identity (heterosexual vs. sexual minority [lesbian, gay, bisexual, or other]), past-month and lifetime tobacco product use, susceptibility to e-cigarette use, friend(s)' e-cigarette use, tobacco marketing exposure, and demographic characteristics. The sample (n=983) was 72.9% female, 46.5% non-Hispanic white, and 26.1% sexual minority with a mean age of 15.0 years (SD=1.4). Sexual minority adolescents were more likely to have friend(s) who vape (53.0% versus 42.0%; p=0.003). In adjusted models, sexual minority adolescents had greater odds of ever smoking tobacco (odds ratio [OR]=2.06; 95% confidence interval [CI]: 1.42-2.98) or using e-cigarettes (OR=1.55; 95% CI: 1.08-2.25) relative to heterosexual adolescents. Past-month tobacco smoking and e-cigarette use did not differ by sexual identity. Among participants who had never used tobacco products, sexual minority adolescents reported greater susceptibility to e-cigarette use (OR=1.62; 95% CI: 1.04-2.52) compared to heterosexual adolescents. Exposure to cigarette and e-cigarette marketing, e-cigarette use by friends, and respondent sex were significant covariates in all models. The current findings indicate greater susceptibility to use e-cigarettes and greater tobacco product initiation, but not continuation, among sexual minority adolescents. Sexual minority-tailored interventions may be warranted to prevent tobacco product initiation. Worth exploring are the associations between sexual identity, tobacco marketing exposure, and friend(s)' e-cigarette use.

Effects of Social Media on Adolescents' Willingness and Intention to Use E-Cigarettes: An Experimental Investigation.

INTRODUCTION: This study examined the effects of experimentally manipulated social media exposure on adolescents' willingness and intention to use e-cigarettes. AIMS AND METHODS: Participants were 135 adolescents of age 13-18 (52.6% female, mean age = 15.3) in California. Participants viewed six social media posts online in a 2 (post source: peer or advertisement) × 2 (e-cigarette content exposure: heavy or light) between-subjects design. Analyses were weighted to population benchmarks. We examined adolescents' beliefs, willingness, and intention to use e-cigarettes in association with social media use intensity in daily life and with experimentally manipulated exposure to social media posts that varied by source (peer or advertisement) and content (e-cigarette heavy or light). RESULTS: Greater social media use in daily life was associated with greater willingness and intention to use e-cigarettes and more positive attitudes, greater perceived norms, and lower perceived danger of e-cigarette use (all p-values <.01). In tests of the experimental exposures, heavy (vs. light) e-cigarette content resulted in greater intention (p = .049) to use e-cigarettes and more positive attitudes (p = .019). Viewing advertisements (vs. peer-generated posts) resulted in greater willingness and intention (p-values <.01) to use e-cigarettes, more positive attitudes (p = .003), and greater norm perceptions (p = .009). The interaction effect of post source by post content was not significant for any of the outcomes (all p-values >.529). CONCLUSIONS: Greater social media use and heavier exposure to advertisements and e-cigarette content in social media posts are associated with a greater risk for e-cigarette use among adolescents. Regulatory action is needed to prohibit sponsored e-cigarette content on social media platforms used by youth. IMPLICATIONS: Adolescents who use social media intensely may be at higher risk for e-cigarette use. Even brief exposure to e-cigarette content on social media was associated with greater intention to use and more positive attitudes toward e-cigarettes. Regulatory action should be taken to prohibit sponsored e-cigarette content on social media used by young people, including posts by influencers who appeal to young people.

Stable isotope evidence (Fe, Cu) suggests that sex, but not aging is recorded in rhesus macaque (Macaca mulatta) bone.

OBJECTIVES: Here, we examine (1) if the sex-related differences in iron (Fe) and copper (Cu) isotope ratios, represented as δ56 Fe and δ65 Cu values, respectively observed in humans exist in bulk occipital bone and incisors of male and female non-human primates, and (2) if the variation of Fe and Cu isotope ratios, known to vary in human blood as a factor of age are similar in non-human primate bone. MATERIALS AND METHODS: Isotope ratios were measured from the skeletal elements of 20 rhesus macaques (Macaca mulatta) with known life history traits. The metals were purified by column chromatography and their isotope ratios measured by MC-ICP-MS. Data were analyzed using generalized additive models (GAM). RESULTS: When accounting for age and sex independently, we found a significant relationship between δ65 Cu values and occipital bone, but not in incisors. There were no significant relationships observed between δ56 Fe values, occipital bone, or incisors. Similarly, there were no significant relationships observed between δ56 Fe values, δ65 Cu values, and age. DISCUSSION: We suggest that Cu and Fe isotope ratios have the potential to be useful supplementary tools in future research in biological anthropology, but additional studies are needed to further verify the relationship between sex, age, δ65 Cu, and δ56 Fe values in primates.

Fermented food consumption in wild nonhuman primates and its ecological drivers.

OBJECTIVES: Although fermented food use is ubiquitous in humans, the ecological and evolutionary factors contributing to its emergence are unclear. Here we investigated the ecological contexts surrounding the consumption of fruits in the late stages of fermentation by wild primates to provide insight into its adaptive function. We hypothesized that climate, socioecological traits, and habitat patch size would influence the occurrence of this behavior due to effects on the environmental prevalence of late-stage fermented foods, the ability of primates to detect them, and potential nutritional benefits. MATERIALS AND METHODS: We compiled data from field studies lasting at least 9 months to describe the contexts in which primates were observed consuming fruits in the late stages of fermentation. Using generalized linear mixed-effects models, we assessed the effects of 18 predictor variables on the occurrence of fermented food use in primates. RESULTS: Late-stage fermented foods were consumed by a wide taxonomic breadth of primates. However, they generally made up 0.01%-3% of the annual diet and were limited to a subset of fruit species, many of which are reported to have mechanical and chemical defenses against herbivores when not fermented. Additionally, late-stage fermented food consumption was best predicted by climate and habitat patch size. It was more likely to occur in larger habitat patches with lower annual mean rainfall and higher annual mean maximum temperatures. DISCUSSION: We posit that primates capitalize on the natural fermentation of some fruits as part of a nutritional strategy to maximize periods of fruit exploitation and/or access a wider range of plant species. We speculate that these factors contributed to the evolutionary emergence of the human propensity for fermented foods.

A Therapeutic Relational Agent for Reducing Problematic Substance Use (Woebot): Development and Usability Study.

BACKGROUND: Misuse of substances is common, can be serious and costly to society, and often goes untreated due to barriers to accessing care. Woebot is a mental health digital solution informed by cognitive behavioral therapy and built upon an artificial intelligence-driven platform to deliver tailored content to users. In a previous 2-week randomized controlled trial, Woebot alleviated depressive symptoms. OBJECTIVE: This study aims to adapt Woebot for the treatment of substance use disorders (W-SUDs) and examine its feasibility, acceptability, and preliminary efficacy. METHODS: American adults (aged 18-65 years) who screened positive for substance misuse without major health contraindications were recruited from online sources and flyers and enrolled between March 27 and May 6, 2020. In a single-group pre/postdesign, all participants received W-SUDs for 8 weeks. W-SUDs provided mood, craving, and pain tracking and modules (psychoeducational lessons and psychotherapeutic tools) using elements of dialectical behavior therapy and motivational interviewing. Paired samples t tests and McNemar nonparametric tests were used to examine within-subject changes from pre- to posttreatment on measures of substance use, confidence, cravings, mood, and pain. RESULTS: The sample (N=101) had a mean age of 36.8 years (SD 10.0), and 75.2% (76/101) of the participants were female, 78.2% (79/101) were non-Hispanic White, and 72.3% (73/101) were employed. Participants' W-SUDs use averaged 15.7 (SD 14.2) days, 12.1 (SD 8.3) modules, and 600.7 (SD 556.5) sent messages. About 94% (562/598) of all completed psychoeducational lessons were rated positively. From treatment start to end, in-app craving ratings were reduced by half (87/101, 86.1% reporting cravings in the app; odds ratio 0.48, 95% CI 0.32-0.73). Posttreatment assessment completion was 50.5% (51/101), with better retention among those who initially screened higher on substance misuse. From pre- to posttreatment, confidence to resist urges to use substances significantly increased (mean score change +16.9, SD 21.4; P<.001), whereas past month substance use occasions (mean change -9.3, SD 14.1; P<.001) and scores on the Alcohol Use Disorders Identification Test-Concise (mean change -1.3, SD 2.6; P<.001), 10-item Drug Abuse Screening Test (mean change -1.2, SD 2.0; P<.001), Patient Health Questionnaire-8 item (mean change 2.1, SD 5.2; P=.005), Generalized Anxiety Disorder-7 (mean change -2.3, SD 4.7; P=.001), and cravings scale (68.6% vs 47.1% moderate to extreme; P=.01) significantly decreased. Most participants would recommend W-SUDs to a friend (39/51, 76%) and reported receiving the service they desired (41/51, 80%). Fewer felt W-SUDs met most or all of their needs (22/51, 43%). CONCLUSIONS: W-SUDs was feasible to deliver, engaging, and acceptable and was associated with significant improvements in substance use, confidence, cravings, depression, and anxiety. Study attrition was high. Future research will evaluate W-SUDs in a randomized controlled trial with a more diverse sample and with the use of greater study retention strategies. TRIAL REGISTRATION: ClinicalTrials.gov NCT04096001; http://clinicaltrials.gov/ct2/show/NCT04096001.