Tobacco use topography and etiology: Similarities and differences among teens and emerging adults

Steve Sussman

doi:10.4103/hm.hm_53_19

REVIEW ARTICLE

Year : 2019 | Volume : 3 | Issue : 4 | Page : 133-139

Tobacco use topography and etiology: Similarities and differences among teens and emerging adults

Steve Sussman
Department of Preventive Medicine and Psychology and School of Social Work, University of Southern California, Los Angeles, California, USA

Date of Submission	09-Sep-2019
Date of Acceptance	07-Nov-2019
Date of Web Publication	23-Dec-2019

Correspondence Address:
Dr. Steve Sussman
Department of Preventive Medicine and Psychology, and School of Social Work, University of Southern California, Los Angeles, California
USA

Source of Support: None, Conflict of Interest: None

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DOI: 10.4103/hm.hm_53_19

Abstract

Tobacco regulatory science seeks in part to reduce harm of new tobacco products. Part of this interest is to help chronic adult smokers switch to potentially less harmful products, while not facilitating use of these modified risk tobacco products by nonusers (particularly teens). Studies to discern a lack of interest in reduced harm products are conducted on emerging adults as a proxy for teens. The present empirical review explores the topography and etiology of tobacco use among emerging adults compared to teens to discern whether they might be a reasonable proxy for such reduced harm studies. Both teens and emerging adults view combustible and e-cigarette smoking as disapproved of by peers and are likely to process tobacco marketing information similarly. I conclude that while some differences do exist (e.g., emerging adults are in a period of escalating use and dependence, whereas teens are relatively likely to be initiating use), emerging adults may indeed be a reasonable proxy, at least for current reduced harm studies.

Keywords: Emerging adults, marketing, MRTPs, products, tobacco use, young and older teens

How to cite this article:
Sussman S. Tobacco use topography and etiology: Similarities and differences among teens and emerging adults. Heart Mind 2019;3:133-9

How to cite this URL:
Sussman S. Tobacco use topography and etiology: Similarities and differences among teens and emerging adults. Heart Mind [serial online] 2019 [cited 2023 May 31];3:133-9. Available from: http://www.heartmindjournal.org/text.asp?2019/3/4/133/273847

Introduction

Combustible tobacco use is a major cause of cardiovascular disease (CVD), among many other diseases, accounting for up to 25% of the cases of CVD.^[1] Noncombustible tobacco products containing nicotine are of concern for persons already suffering from CVD but may reduce risk of CVD among relatively healthy tobacco users.^[2] Modified risk tobacco products (MRTPs) are sold to reduce the risk of harm associated with current commercially marketed tobacco products. Premarket tobacco product applications must provide scientific data to demonstrate that those who do not use tobacco products will not start using the proposed products. This is particularly an issue regarding teens. Typically, studies have been completed to assess perceived safety, accessibility, and interest or intentions in trying the proposed tobacco products. If potential MRTPs enhance perceptions of safety, accessibility, and interest in using them by nonusers (particularly teens), then such products possibly should not be marketed or should be restricted in other ways (e.g., available through pharmacies only). See https://www.fda.gov/tobacco-products/tobacco-product-review-evaluation/premarket-tobacco-product-applications, accessed on June 18, 2019; and also see https://www.fda.gov/tobacco-products/advertising-and-promotion/modified-risk-tobacco-products, accessed on June 18, 2019.

Tobacco companies engage in the assessment of youth interest in MRTPs by studying emerging adults (19-to-25 years of age) as a proxy for underage teens in pursuit of MRTP FDA approval. Some recent products (SNUS, iQOS) may have involved presenting data, suggesting that emerging adults are relatively uninterested in these products, such that these “reduced harm” products might be an option for persons who seek lowered risk of disease. In this review, I explore similarities and differences between teens and adults to discern if such MRTP data collected on emerging adults might be applicable to teens. Specifically, I provide information on youth development, tobacco use trends, reasons for use, and cognitive processing characteristics considering emerging teens, older teens, and emerging adults. The studies selected provide a reasonably complete illustration on how youth across this age duration might be impacted by potential MRTPs.

General Information on Youth Development

To better understand human development across this age range, it is helpful to break age groups down a little more. In this section, I will highlight differences between young teens (here delineated at 12-to-14 years old), older teens (15-to-18 years old), and emerging adults (19-to-24 years old).^[3] To generalize, one might say that young teens attend elementary school or junior high school in the U.S., and they are in a “stage” within which they tend to achieve identity through the group, a reputation-based collective.^[3],[4] Older teens have reached senior high school in the U.S., and are in a stage within which they have achieved a general sense of self but may not have yet developed specific facets of self-behavior.^[5] For example, older teens may view themselves as a moderate type of person but may not have a definitive sense yet regarding which behaviors are moderate (e.g., whether texting and driving are something a moderate person does, whether tobacco use is what a moderate person might do). What has been referred to as “emerging adulthood,” on the other hand, is a stage within which youth search for intimacy with another person, preparing to enter an adult world of work and love, and this stage is resolved by “settling down.”^[6] Emerging adults typically attend college or trade school, may have both a general sense of self and a sense of specific facets of self-behavior, but they are encouraged by the large social environment to explore their development more before settling down (to “sew the wild oats”).

Young teens (12-to-14 years old)

Young teens are in a period of rapid physical growth. Thinking abstractly, or understanding ambiguity, may be difficult.^[7] Decision-making skills are just forming among young teens. Young teens are only starting to become aware of media influences. Young teens are most subject to peer social influences. Parents are relatively unlikely to serve as a mechanism of friendship selection, although they often monitor and gate keep regarding peers that they know about.^[4],[8]

Young teens that are at a higher pubertal stage than their peers are relatively likely to experiment with smoking and possibly try other drugs.^[5],[9] Young teens, who are curious about experiential solutions to their search for identity and who are approached by other teens who share a similar curiosity, may seek out or yield to offers to try tobacco or other drugs or engage in other risky behaviors. They also may be struggling academically.^[4],[10]

Personalized smoking risk perceptions tend to decline beginning in the tween years and early adolescence, possibly leading to relative overestimates of perceived safety of smoking and other tobacco use.^[11] Prevalence overestimates of tobacco and other drug use exist during this age period and may normalize tobacco use.^[12]

Older teens (15-to-18 years old)

Older teens are in the process of solidifying a sense of self and tend to become more resistant to direct influence (e.g., regarding peer smoking offers).^[13] Intrapersonal motivations become more important.^[14] Older teens may be more sensitive and react negatively to social pressures that contradict their attempts to achieve specific facets of a sense of self. Older teens also tend to socialize in contexts of heterosexual crowds and less mutually dependent on small groups of same-sex peers (which is the case with young teens), and they tend to begin dating and engage in other behaviors in preparation for an emerging adulthood lifestyle.^{[4],[13],[15],[16]}

Older teens exhibit rapid neurobiological changes. Reinforcers may be experienced as relatively rewarding compared to later in adulthood, whereas executive inhibitory processes may not operate as efficiently.^[15] For example, the reinforcing value of some behaviors (e.g., kissing, tobacco use, and alcohol use) may be much greater than later in the middle adulthood (older than 25), while there is relatively less inhibitory neocortical functioning in operation concurrently.

Age-relevant reinforcing behaviors may tend to be associated with each other among older teens. For example, smoking intentions in older adolescence may be related to interest in dating.^[17] While young adolescence has been identified as being the period in which much of smoking initiation occurs, older teen nonsmokers (e.g., 15-year-olds) are still susceptible to beginning smoking, particularly if they perceive smoking as resulting in social benefits (e.g., appearing attractive to potential romantic partners) or if they are receptive to tobacco industry marketing.^[4],[9],[18] Tobacco and other drug use may come to serve more as a stress-coping (intrapersonal) function as the substance use acquisition process enters a more advanced phase (regular use).^[14] Decision-making skills still may be lacking.

Emerging adulthood (19-to-25 years old)

Emerging adulthood is a developmental period in which youth grapple with the prospects of new opportunities (e.g., independent living, job training) and need to select among them and decide on a firm course in adulthood.^[6],[19] During this life transition, individuals achieve relative autonomy from guardians, such as parents, and experience shifts in social roles and normative expectations for their behavior. Emerging adults are typically free from dependency that characterized childhood (e.g., relatively close parent and teacher guidance) yet are not burdened with the responsibilities of adulthood (e.g., career and parenthood). This freedom allows emerging adults the opportunity to explore diverse potential life directions.

Five distinct dimensions of emerging adulthood have been proposed: the age of identity explorations, the age of feeling in-between (not quite an adult), the age of possibilities (optimism), the self-focused age, and the age of instability.^[20],[21] The last dimension of emerging adulthood refers to the contradiction that lies with the excitement of exploring life's options and paradoxically the fear that such a great number of possibilities elicits.

Young people leaving high school are expected to seek out and select from among new opportunities.^[22] These include (1) pursuing and assuming career avenues and financial independence, (2) learning skills of independent living (buying or renting a place to live), (3) enhancing self-care skills (cooking, cleaning, grooming, buying goods, and traveling), and (4) participating in social adventures (e.g., love and emerging adult groups). Social adventures may eventually lead to commitment in relationships (e.g., marriage and children). Youth may also transition from a relatively high level of family conflict in adolescence to the reduction of such conflict in emerging adulthood as they achieve emotional distance from parental demands and associate more continuously with peers. The focus is on exploring as much as possible and then settling down; they are encouraged to “sew the wild oats.”

Successful transitioning through emerging adulthood involves being able to view exploration of life options as positive, hold positive general attitudes about life, become increasingly other-oriented (nurturing), and not feel subjectively caught in between adolescence and adulthood. For emerging adults, fear or lack of hope that one will be able to satisfactorily settle down into adult roles is a driving source of pressure that might lead one to resort to tobacco or other drug use or other self-destructive behavior.^{[19],[22],[23]}

Tobacco Use Trajectories as a Function of Developmental Period

Nearly 90% of adult smokers begin smoking before 18 years of age, and 9.7% of high-school seniors report smoking in the last month (https://www.hhs.gov/ash/oah/adolescent-development/substance-use/drugs/tobacco/trends/index.html, accessed May 20, 2019). These data might suggest that tobacco use development is more relevant to the teen years, whereas maintenance of smoking is characteristic of emerging adults and adults. However, as discussed by Villanti et al.,^[24] the emerging adult years are the period of greatest escalation and entrenchment of smoking, significant initiation of cigarette and other combustible tobacco use still occurs after age 18, and smoking patterns tend to stabilize by 25 years of age. I focus mostly on comparison of use among older teens versus emerging adults in the next two subsections.

Current tobacco use trends among young and older teens

Last 30-day use of any tobacco product in 2018 was 27.1% among high-school youth Grades 9–12 (older teens).^[25] As measured by the Monitoring the Future study,^[26] in 2018, 30-day prevalence of cigarette smoking among 12^th graders decreased from 39% in 1976 to under 10% in 2018. Initiation of smoking among 8^th graders (14-year-old young teens) decreased from a peak of 49% in 1996 to 9% by 2018. Among 12^th graders, the last 30-day smokeless tobacco use declined from a 1995 peak of 12.2% to 4.2% in 2018. The past 12-month prevalence of hookah pipe use, first measured in 2010, decreased from 17.1% in 2010 to 7.8% by 2018. Only 5% of the 12^th-grade students in 2018 reported use on more than two occasions of hookah use during the prior 12 months. Regarding little cigars and cigarillos and large cigars, 30-day prevalence among 12^th graders in 2018 was 8.9% for flavored and 5.8% for regular little cigars or cigarillos (down from 11.9% and 7.0%, respectively, in 2014 when first measured) and was 5.2% for large cigars (down from 6.4% in 2014).

Conversely, annual e-cigarette prevalence increased dramatically from 2017 to 2018 among 12^th graders, with annual prevalence of vaping nicotine being 16.6% in 2017 and 26.7% in 2018. Monthly prevalence of vaping nicotine (i.e., at least once per month) increased from 11% to 20.9%, respectively, from 2017 to 2018.^[25] Among 8^th graders (young teens), initiation of vaping nicotine increased from 10.6% to 13.5%, and monthly prevalence of vaping increased from 3.5% to 6%, over this same period. E-cigarette use appears to be the dominant tobacco substance used by older adolescents currently and accounts for the high overall prevalence of tobacco use among older teens.

Current tobacco use trends among emerging adults

Among college youth and other emerging adults, the declines in the use of combustible tobacco have been less dramatic. However, the 8.0% last 30-day cigarette smoking prevalence for college students reported in 2017 had decreased from 31% in 1999. Schulenberg et al.^[27] noted that the decline accelerated after 2005, reflecting a cohort effect that “worked its way up the age bands.” CDC^[28] noted a slightly higher “current smoking” prevalence of 10.4% among 18-to-24-year-old youth in 2017 (i.e., smoked at least 100-lifetime cigarettes and smoked “every day” or “some days”), which may reflect inclusion of noncollege youth. Thirty-day prevalence of vaping nicotine was much higher for males than females among both college students (11% versus 3.2%) and noncollege youth (12% versus 4.9%).

In November 2017, the Schroeder Institute at Truth Initiative conducted a national, online survey among people aged 15–24 years (convenience sample n = 1012) to examine product perceptions and use of JUUL.^[29] Compared with those aged 15–17 years (older teens), those aged 18–24 (mostly emerging adults) were more likely to recognize JUUL (29% vs. 21%) and report ever using a JUUL (12% vs. 7%). Only 37% of the past 30-day users reported that JUUL always contains nicotine. Thus, emerging adults have been rapidly increasing use of e-cigarettes and newer e-cigarette brands, again, possibly reflecting an aging cohort.

Reasons for Tobacco Use as a Function of Developmental Period

Perceived risk

Harm perceptions are predictive of tobacco use in teens and emerging adults.^[30] Schulenberg et al.^[27] found that in 2017, about 85% of emerging adults perceived regular pack-a-day cigarette smoking as entailing high perceived risk. However, 18-year-olds had been reporting consistently lower perceived risk than emerging adults at 74%.^[26] Likewise, the regular use of smokeless tobacco was reported as dangerous by approximately 55% of emerging adults and 38% of 12^th graders (older teens) in 2017. Perceived risk of using e-cigarettes regularly in 2017 was found among 27% of emerging adults and 16% among 12^th graders. Thus, there may be some differences found on perceived risk, comparing emerging adults to older teens. Older teens perceive lower risk of consequences of tobacco products than emerging adults.

Across age groups, there is a notable difference in the perception of harm comparing tobacco products. In Soneji et al's^[31] sample of adolescents (12-to-17 years old, both young and older teens) and mostly emerging adults (18-24 years old), both groups endorsed beliefs that e-cigarettes might be less harmful than combustible cigarettes to themselves (75.0% of adolescent users and 81.0% of emerging adult users) or other persons (74.2% of adolescent users and 84.2% of young adult users).

Disapproval

In 2017, among 18-year-olds versus 19-to-22-year-olds, 87% versus 85% disapproved of pack-or-more-a-day smoking,^[27] respectively. Likewise, peer disapproval of combustible cigarette smoking was very high across both age groups. In 2017, 85% of 12^th graders (older teens) said that their friends would disapprove of pack-a-day smoking as did 90% of 19-to-30-year-olds (emerging adults and adults). Thus, disapproval of combustible tobacco appears consistent across age groups.

Likewise, disapproval of regular e-cigarette use (vaping an e-liquid) was 68.9% and 70.9% among 8^th and 12^th graders (young teens and older teens, respectively) in 2018. Also, 60.8% and 59.2%, respectively, disapproved of occasional use. It is not yet clear to what extent e-cigarette use is disapproved of among emerging adults, at least as assessed by the Monitoring The Future (MTF) Survey. However, among a sample of general population near-emerging adults who ever used an e-cigarette (n = 614, mean age = 18.9), Hong et al.^[32] found that 34.8% did perceive e-cigarettes as more acceptable than combustible cigarettes to nontobacco users. While future work is needed, one may speculate that perceived disapproval of e-cigarette use is likely similar between teens and young adults (around 70% perceive that e-cigarette use is disapproved of by others). Furthermore, it appears that both groups view e-cigarettes as less disapproved of than combustible cigarettes.

Accessibility to tobacco

While e-cigarettes and other tobacco products are legal to purchase and more accessible among persons 18 (or 21) years of age and older (depending on the location), they are easy to acquire among young and older teens.^[26] Certainly, legality of purchase differentiates emerging adults from teens. Emerging adults may buy tobacco products directly and legally, whereas teens purchase them illegally (with or without false IDs) or through older persons such as older siblings or other adults. Thus, the context of acquiring tobacco is rather different for teens and emerging adults.

Marketing, flavors

Emerging adults are a vulnerable population for tobacco use as they are a prime target for marketing and advertising by tobacco/vaping companies.^[24] In fact, receptivity to advertisements (recall and liking of specific tobacco ads) has been found to be higher among youth 18-to-21 years old (mostly emerging adults) compared to youth 12-to-17 years old (n = 10,989) and was associated with tobacco use 1 year later.^[33] While not targeting teens prima facie, certainly, young and older teens are impacted by tobacco and vaping industry advertisements and marketing lures, including promotion of sweet flavors. Soneji et al.^[31] assessed the prevalence of flavored e-cigarette use within the past month by flavor types and concurrent use of multiple flavor types among the past month e-cigarette users (Population Assessment for Tobacco and Health Study; 414 young and older adolescents [12-to-17 years old], 961 mostly emerging [18-to-24 years old], and 1711 older adults [25 years old or older]). Compared with adults, emerging adults were more likely to use fruit-flavored e-cigarettes and candy-flavored e-cigarettes and concurrently used multiple flavor types. The leading reason for use of e-cigarettes among adolescents and emerging adults was the availability of appealing flavors: 77.9% of 12-to-17-year old users and 90.3% of 18-to-24-year old users selected this reason. Likewise, Hong et al.^[32] found that the top reason for e-cigarette use among emerging adults was “They come in flavors I like” (56.6%). Certainly, in terms of potential for marketing influence and preference for (fruit/sweet) flavored e-juices, teens and emerging adults appear quite similar. Emerging adults may have more of a preference for mint/menthol than teens, however.^[31]

Using e-cigarettes to quit combustibles

Teens do try to quit tobacco use with or without cessation services.^[34] However, no studies were found indicating that teens use e-cigarettes to help them quit combustible cigarettes. Primary care settings until recently have not even assessed teens for alternative tobacco use.^[35] Use of nicotine among teens in any form is questionable in any case given potential impact on executive cognitive function.^[1] Anecdotally, teens do look for substitutes when contemplating quitting combustible tobacco (including using cannabis as a tobacco quit tool),^[4] so it is possible that a few teens may wonder if e-cigarettes might be a harm reduction tool.

Hong et al.^[32] found that among emerging adults, using e-cigarettes to quit smoking was uncommon (12.8%). Since the average age of their sample was 18.9 years, it is very likely that few teens look toward e-cigarettes to quit combustibles. Likewise, Olfson et al.^[36] using NESARC data found that most emerging adults (18-to-25 years of age) who used e-cigarettes, even most who used them frequently, did not report using them to help reduce combustible tobacco use.

Unfortunately, examined over 3 years, it appears that emerging adult tobacco users converge on combustible tobacco use, no matter what their type of baseline tobacco product was (e-cigarette, combustible tobacco, or dual user).^[37] Thus, e-cigarette use would be not recommended for any young tobacco user, teen or emerging adult, as a harm reduction device, due to a tendency to drift eventually toward combustible tobacco.

Dependence on e-cigarettes

Heavier tobacco users as teenagers are relatively likely to use tobacco as emerging adults.^[38] Villanti et al.^[24] mentioned that key predictors of smoking progression in emerging adulthood include the experience of dependence symptoms. Thus, studies of emerging adult smokers are likely to consist of persons who were more dependent on nicotine as teens.

Peltier et al.^[39] found that 1370 undergraduate dual users reported significantly longer smoking histories and more past quit attempts than other smoking groups. Those reporting dual-use reported higher expectancies of positive and negative reinforcement and appetite/weight control. E-cigarette use among these emerging adults was found to be a negative predictor of cessation attempts.

Other drug use, mental health, and tobacco use

Many studies have been completed that have demonstrated the association of drug use (e.g., alcohol, marijuana, other drugs) and mental health, with tobacco use among young and older teens and emerging adults.^{[5],[40],[41],[42],[43]} For example, McCuller et al.^[40] noted associations of tobacco with other drug use and with depression, trait anxiety, and family conflict among 1315 high school age teens, as part of a larger canonical correlation study. In a community-based study of 1106 high school age, older adolescents, Audrain-McGovern and colleagues found that teens with higher self-reported anhedonia were more likely to initiate and escalate levels of smoking.^[42] Creamer et al.^[43] found that stress relief was the major positive outcome expectation associated with initiation of smoking among 3907 11-to-16 year olds (mostly young teens).

Likewise, among emerging adults, Villanti et al.^[24] reported that key predictors of smoking progression included mood elevation and regulation. Likewise, Olfson et al.^[36] suggested that emerging adult's intentions to use e-cigarettes are more closely related to affect regulation, social enhancement, and positive sensory experiences than to avoid negative health outcomes of combustible cigarette smoking. Bierhoff et al.^[44] examined the mental health of 2397 U.S. college students (aged 18–25), revealing that cigarette and little cigar/cigarillo use was predicted by greater depressive and anxiety symptoms. Furthermore, nicotine dependence was correlated with greater anxiety symptoms. Berg et al.^[45] used ecological momentary assessment to examine timing, tobacco cravings, affect, social context, other substance use (alcohol, marijuana), relations with of cigarettes, electronic nicotine delivery systems (ENDSs), and any tobacco product (i.e., cigarettes, ENDS, cigars, hookah) use among 31 21-year-old tobacco users. Predictors of cigarette use included higher anxiety, greater odds of marijuana and alcohol use, and higher boredom levels among women. Predictors of ENDS use included being non-White and greater odds of marijuana use, as well as higher boredom among men. Predictors of any tobacco product use included higher boredom levels and greater odds of marijuana and alcohol use. In summary, for young and older teens and emerging adults, tobacco initiation or experimentation is associated with mental health symptoms (particularly of anxiety and depression) as well as other drug use.

Smoker identity

Possibly, young and older teens who experiment with tobacco are relatively less likely to hold a “sense of self” as a tobacco user compared to emerging adults. After all, they have experimented with tobacco for a shorter time and at lighter levels than young adults. However, among teen tobacco use experimenters, those who do hold a smoker identity are relatively likely to continue smoking.^[46] Hertel and Mermelstein^[46] investigated associates of smoker's identity among 9^th and 10^th grade, older adolescents who smoke (n = 292) over a 2-year period. Increases in negative affect coping motives were found to be associated with smoker identity development among both males and females. In addition, increases in social motives were associated with smoker identity development among males.

Villanti et al.^[24] mentioned that one of the key predictors of smoking progression during emerging adulthood includes identity as a smoker. A systematic electronic literature search was conducted by Tombor et al.^[47] to identify qualitative studies on smoker identity in smokers and ex-smokers 16-to-34 years old. Contributory factors to smoker identity among these older teens, emerging adults, and adults were found to include the desire to establish aspirational individual and social identities, enact a smoker identity appropriate to the momentary social context, and alter personal nonsmoking rules when consuming alcohol. Possibly, emerging adult tobacco use identity is relatively more strongly related to social identity than young and older teens, whereas teen tobacco use identity is relatively strongly related to coping with negative affect. That is, while not as important as among teens as a means of affect regulation, regular and older tobacco users may view themselves as a sort of tobacco user community.

Cognitive Processing: Possible Implications for Processing Marketing Material

In early adolescence (around 12 to 14 years of age), puberty contributes to emotional arousability and an increased reward orientation, which unfolds into participation in risky behaviors during mid-adolescence (around 15 to 16 years of age), whereas in late adolescence (around 17 to 18 years of age), maturation of frontal lobes increases in regulatory capacity,^[48] though rapid changes in neurodevelopment continue until the sometime in the mid-20s (particularly in terms of maturation of the frontal lobes/prefrontal cortex).^[49] Successful transition to adulthood, which may occur as late as the mid-20s (the end of emerging adulthood), involves successful brain system integration, involving social cognitive refinements and integration with motivational-affective and cognitive control systems, which permits maximal coping with peer social influence and group inclusion/exclusion.^[50]

Young and older teens do appear relatively more subject to a context of direct peer influences and show relatively less neurodevelopmentally-based inhibitory executive control than emerging adults, possibly leading to differences in risky decision-making, even though they may share the same logical competencies.^{[48],[51],[52]} One major difference, however, between young and older teens and emerging adults is the operation of large social contextual pressures in emerging adulthood that may negate somewhat advanced development of inhibitory processes relative to teens. Across the lifespan, risky behavior is encouraged or at tolerated the most during emerging adulthood.^[19] Arguably, teens and emerging adults are likely to process marketing information very similarly in terms of favorability. Emerging adults may process messages more critically than teens but also with a view toward relatively greater exploration of lifestyle possibilities, including tobacco use.

Summary and Conclusions: Extrapolating from Emerging Adults to Adolescents

Teens learn their social world first in small same-sex groups (young teens) and then in larger heterosexual crowds (older teens) – about which direct social influences operate, though in older adolescence, such influence tends to fade in importance, succeeded gradually in importance by indirect influence of a larger social world (e.g., mass, social media). Parents operate at first as direct gatekeepers of friends among tweens and later as more indirect monitors. Curiosity, peer group influences, and opportunity lead to initiation of tobacco use. Rewards have relatively high neurobiological salience, whereas inhibitory processes operate relatively less effectively, throughout the teen and emerging adult years compared to adults over 25 years. Among emerging adults, while brain development is becoming more advanced, the large social climate provides a relatively strong influence to take new risks or continue to take risks.

Combustible tobacco use has decreased in prevalence among young and older teens and emerging adults recently, with a corresponding increase in use of e-cigarettes. In the last 2 years, growth in the use of pod mods appears to be at least as great or greater among emerging adults as compared to teens. Pod mods (e.g., JUUL, Suorin, Puff Bar) are dominating the e-cigarette tobacco market, which accounts for about 5% of the total tobacco market. Combustible cigarettes still account for about 83% of the market as of 2018, and other products (e.g., smokeless tobacco, cigars) account for the remainder.^[53] Teens and emerging adults may either converge later in middle adulthood to use combustible tobacco, or possibly, e-cigarettes will dominate the total market as these cohorts age. At present, it is not clear—but it does look like e-cigarettes will dominate the market in the next several years as the price becomes more affordable. The general pattern of preference for types of tobacco products appears similar between young and older teens and emerging adults.

Perceived risk of combustible and smokeless tobacco use harm apparently increases from older adolescence into young adulthood while, at the same time, regular use and addiction are relatively likely. That is, as youth grow older they may be more aware of harm but less able to quit. Legality of purchasing tobacco certainly makes the accessibility of tobacco greater among emerging adults than teens, though teens view tobacco products as easy to acquire. Both teens and emerging adults are relatively likely to prefer and use fruit and candy-flavored e-cigarettes, or multiple flavors, compared to older adults. It does appear uncommon that teens or emerging adults view e-cigarettes as a way to quit combustible cigarettes (maybe around 13% of e-cigarette users).

Among young and older teens and emerging adults, tobacco use is associated with stress relief, anhedonia, and trait anxiety and may be used in part as a means of mood elevation and regulation, though emerging adults use tobacco relatively more as a means of “social identity”. Those teens who do have a smoker identity are relatively likely to continue smoking throughout emerging adulthood. Contextual factors in emerging adulthood maybe even stronger than among teens to engage in risky behavior such as tobacco use. Overall, though, young and older teens and emerging adults are likely to process tobacco marketing information similarly. MRTP-related research on emerging adults is quite likely to generalize to young and older teens.

One caveat should be mentioned. Recently, there has been a policy in the U.S. to change the legal age to purchase tobacco products to 21 years (“Tobacco 21”; e.g., see: https://tobacco21.org/enforcement-memo/; accessed 11-3-2019). More than 270 localities in more than a dozen states have enacted ordinances, raising the minimum age for tobacco sales to 21. In 2015, Hawaii became the first state to enact such a law. California followed suit in 2016, followed by Maine, New Jersey, and Oregon in 2017. If 21 years of age becomes the minimum age to use tobacco throughout the U.S. and in other countries, then the current MRTP-related research would need to be fixed within a 21-to-25-year-old age range. It is not clear whether the current testing would then be appropriate.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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