Electronic cigarette use and suicidal behaviors among adolescents

E-cigarette use or dual use of E-cigarette and combustible cigarette and mental health and cognitive impairment: Findings from the National Health Interview Survey, 2020-2021

BACKGROUND

Studies on the association between e-cigarette use and mental health are mostly among adolescents and young adults, leaving limited evidence of this association among general US adults. Besides, few studies have examined how e-cigarette use or dual use of e-cigarette and combustible cigarette is related to cognitive function.

METHODS

Cross-sectional data of 56,734 adults from the 2020-2021 National Health Interview Survey were analyzed. Weighted multivariable logistic regression models were applied to examine the independent association between e-cigarette use or dual use and anxiety symptoms, depression symptoms, serious psychological distress (SPD), and cognitive impairment.

RESULTS

Compared with never e-cigarette users, current e-cigarette users had 2.10-fold (95 % CI: 1.84, 2.39), 2.53-fold (95 % CI: 2.13, 3.00), 2.02-fold (95 % CI: 1.47, 2.76), and 2.00-fold (95 % CI: 1.47, 2.72) higher odds of reporting anxiety symptoms, depression symptoms, SPD, and cognitive impairment, respectively. Former e-cigarette use was also associated with all three mental conditions and cognitive impairment (AOR ranged from 1.38 to 2.53, all P < 0.01). Dual users were more likely to report all three mental conditions and cognitive impairment than those who never used combustible cigarette and e-cigarette (AOR ranged from 1.89 to 2.83, all P < 0.01). Dual users also had a greater likelihood of having anxiety or depression symptoms than exclusive combustible cigarette users (AOR ranged from 1.46 to 1.47, all P < 0.01).

CONCLUSIONS

E-cigarette use or dual use is associated with poor mental health and cognitive impairment among US adults. Regulations on e-cigarette use are needed to prevent mental illness and improve cognitive function.

Use of Tobacco Products and Suicide Attempts Among Elementary School-Aged Children

Importance

The use of tobacco products, including e-cigarettes and vaping, has rapidly increased among children. However, despite consistent associations found between smoking cigarettes and suicidal behaviors among adolescents and adults, there are limited data on associations between emerging tobacco products and suicidal behaviors, especially among preadolescent children.

Objective

To examine whether the use of tobacco products is associated with nonsuicidal self-injury (NSSI), suicidal ideation (SI), and suicide attempts (SAs) among preadolescent children.

Design, Setting, and Participants

This cohort study, conducted from September 1, 2022, to September 5, 2023, included participants in the Adolescent Brain Cognitive Development study, a population-based cohort of 11 868 US children enrolled at 9 and 10 years of age. The cross-sectional investigation focused on 3-year periods starting from the baseline to year 2 of follow-up. Statistical analysis was performed from October 1, 2022, to June 30, 2023.

Main Outcomes and Measures

Children's use of tobacco products was assessed based on youth reports, including lifetime experiences of various nicotine-related products, supplemented with hair toxicologic tests. Main outcomes were children's lifetime experiences of NSSI, SI, and SAs, assessed using the K-SADS-5 (Kiddie Schedule for Affective Disorders and Schizophrenia for the DSM-5). Multivariate logistic regression was conducted to examine the associations of the use of tobacco products with NSSI, SI, and SAs among the study participants. Sociodemographic, familial, and children's behavioral, temperamental, and clinical outcomes were adjusted in the analyses.

Results

Of 8988 unrelated study participants (median age, 9.8 years [range, 8.9-11.0 years]; 4301 girls [47.9%]), 101 children (1.1%) and 151 children (1.7%) acknowledged lifetime use of tobacco products at baseline and at 18-month follow-up, respectively. After accounting for various suicide risk factors and potential confounders, children reporting use of tobacco products were at a 3 to 5 times increased risk of SAs (baseline: n = 153 [adjusted odds ratio (OR), 4.67; 95% CI, 2.35-9.28; false discovery rate (FDR)-corrected P < .001]; year 1: n = 227 [adjusted OR, 4.25; 95% CI, 2.33-7.74; FDR-corrected P < .001]; and year 2: n = 321 [adjusted OR, 2.85; 95% CI, 1.58-5.13; FDR-corrected P = .001]). Of all facets of impulsivity measures that were significant correlates of use of tobacco products, negative urgency was the only independent risk factor for SAs (adjusted OR, 1.52 [95% CI, 1.31-1.78]; FDR-corrected P < .001). In contrast, children's alcohol, cannabis, and prescription drug use were not associated with SAs.

Conclusions and Relevance

This study of US children suggests that the increased risk of SAs, consistently reported for adolescents and adults who smoke cigarettes, extends to a range of emerging tobacco products and manifests among elementary school-aged children. Further investigations are imperative to clarify the underlying mechanisms and to implement effective preventive policies for children.

Beyond the label: current evidence and future directions for the interrelationship between electronic cigarettes and mental health

Electronic cigarette use has dramatically increased over the last decade. With this recent technological development and wide range of constituents in various products, putative adverse effects on the brain and body have been largely unexplored. Here, we review current evidence linking electronic nicotine cigarette use with potential health consequences and provide evidence supporting an association between drug use and depression in humans. We also examine the biological effects of individual constituents in electronic cigarette aerosols, which include labeled ingredients, such as propylene glycol, vegetable glycerin, nicotine, and flavorants, as well as unlabeled ingredients found in the aerosols, such as carbonyls and heavy metals. Lastly, we examine the effects of electronic cigarette use on endogenous metabolism via changes in cytochrome P450 enzymes, which can thereby impact therapeutic outcomes. While the current evidence offers insight into the potential effects of electronic cigarette use on biological processes, further studies are necessary to determine the long-term clinical relevance of aerosol inhalation.

Suicidal Behaviour among School-Going Adolescents in Saint Lucia: Analysis of Prevalence and Associated Factors

Suicide poses a debilitating threat to adolescents' lives worldwide. Although suicide prevention efforts are evident globally, there is limited evidence on the prevalence and correlations of suicidal behaviour among school-going adolescents in Saint Lucia. We used a dataset from the 2018 Global School-based Student Health Survey to examine the prevalence and associated factors of suicidal behaviour among 1864 students from schools in Saint Lucia. Prevalence rates of 25.5%, 22.1%, and 17.5% were found for suicidal ideation, suicide plan, and suicide attempt, respectively. After adjusting for other factors, being male and having understanding parents were protective against suicidal behaviour. However, suicidal ideation was predicted by being physically attacked and bullied, parental guidance, tobacco use, loneliness, and worry. Moreover, being a victim of physical attacks and bullying, having close friends, being lonely, and worrying were predictive of making suicidal plans among adolescents. Attempting suicide was predicted by cigarette smoking, current use of tobacco and related products, bullying, having close friends, being lonely, and worrying. School-based preventive interventions are required to help address triggers of suicidal behaviour among adolescents in Saint Lucia and to help attain the targets for suicide prevention in the global Sustainable Development Goals.

Vaping and Sleep as Predictors of Adolescent Suicidality

PURPOSE

To investigate sleep quantity as a moderator of vaping and self-reported suicidality among adolescents.

DESIGN

Cross-sectional. Setting: United States high schools.

SAMPLE

10,520 high-school students with complete data on the primary outcome of suicide attempt in the past year (76.9% response rate).

MEASURES

2019 Youth Risk Behaviors Survey.

ANALYSIS

Logistic regression to examine main effects and potential moderation.

RESULTS

Students with under seven sleep hours on school nights (OR = 2.6; 95% CI = 2.1-3.3) and who vaped in the past month (OR = 3.0; 95% CI = 2.1-3.9) had higher odds of attempting suicide in the last year. Sleep quantity moderated the relationship between vaping and suicidal thoughts in the past year (P = .01) but did not moderate the relationship between vaping and a suicide plan (P = .15) or suicide attempts (P = .06). Specifically, vaping had a smaller effect on suicidal thoughts among students who slept under seven hours on school nights (OR = 1.8) compared to the descriptively larger effect among participants with more sleep (OR = 2.5).

CONCLUSIONS

Students who vape or report low sleep quantity would be ideal participants in suicide prevention interventions as they may be at higher risk for suicidality. Organizations implementing sleep or vaping interventions should incorporate information regarding the higher odds of suicide among students with low sleep quantity or vaping habits.

Vaping and Mental Health Conditions in Children: An Umbrella Review

The e-cigarette (EC) epidemic began in the United States (US) in 2007; since 2014 EC is the most commonly used form of tobacco. However, the mental health implications of vaping are grossly unknown. The aim of this umbrella review is to provide astate-of-the-art summary of existing research concerning vaping and mental health conditions in children. Following the PRISMA Statement 2020 guidelines, a systematic search was conducted across PubMed, Cochrane Library, and Google Scholar up to April 15th, 2022 to locate relevant studies. The Joana Briggs Institute (JBI) methodology for umbrella reviews and quality appraisal tool was utilized. Six studies, pooling a total of 846,510 adolescents aged 21 years or below, were included by collating 85 primary clinical studies. Of these, 58.8% of the primary clinical studies originated in the US, with 4.7% from Canada, South Korea, and the United Kingdom each; 3.5% each from England and Taiwan; 2.4% each from Australia, France, Hawaii, Mexico, and Russia; and 1.2% each from Denmark, Greece, Hong Kong, Iceland, New Zealand, Poland, and Switzerland. Overall, significant associations were found between mental health outcomes, including depression and suicidality, among current EC users and those who had ever used EC. Compared to adolescents who had never used EC, both depression and anxiety were reportedly higher among EC users. Impulsive behaviors, reported as impulsivity, were also found to be correlated with the adoption of EC use. However, there is a lack of evidence regarding the impact of EC use on mental health outcomes in children. This umbrella review highlights the urgent need to further explore the effects of current EC use from a psychiatric and public health perspective.

Smoking Susceptibility in Canadian Adolescent Electronic-Cigarette Users

Background: E-cigarette use is increasing among Canadian youth, with experimentation especially prevalent among never-smoking youth. Among this group, there is concern e-cigarette use contributes to future initiation of smoking through a gateway effect. However, e-cigarette use and smoking share many common risk factors; a postulated mechanism to explain the apparent causal pathway from e-cigarette use to smoking initiation in previously smoking-naïve youth. A better understanding of the relationships between smoking susceptibility and e-cigarette use among never-smoking youth is needed. Purpose/objectives: The primary aim of this study was to gain a deeper understanding of the risk factors associated with smoking susceptibility in youth who have recently used e-cigarettes. Methods: This study used data (n = 40,363) from the 2018/2019 Canadian Student Tobacco Alcohol and Drug Use Survey (CSTADS) to compare the risk factor profiles of susceptible and non-susceptible never-smoking e-cigarette users, as well as susceptible and non-susceptible never-smoking youth who have never used an e-cigarette. Results: E-cigarette use, independent of susceptibility status, was associated with a sociodemographic and behavioral risk factor profile likely to confer a higher risk of initiating smoking. Among e-cigarette users, smoking susceptibility was associated with more smoking risk factors. Conclusions/importance: Study findings support a common risk-factor model, rather than e-cigarette use itself, to explain differences in the likelihood of smoking initiation among e-cigarette users. E-cigarette use and smoking initiation may be interchangeable outcomes amongst those with smoking risk factors. The risks of e-cigarette use, and their regulatory status, need to be balanced with their potential as harm reduction tools.

Use of electronic vaping products and mental health among adolescent high school students in the United States: The moderating effect of sex

Although studies have investigated the association between conventional tobacco smoking and mental health outcomes among adolescents in the United States, few studies have examined the association between electronic vaping products (EVPs) and mental health among adolescents. This study aimed to investigate the cross-sectional association between EVPs use, symptoms of depression, and suicidal behaviors among adolescents. Data were pooled from the 2017 and 2019 Youth Risk Behavior Survey. An analytic sample of 14,285 adolescents (50.3% female) was analyzed using binary logistic regression. The outcome variables investigated were symptoms of depression, suicidal ideation, suicide plan, and suicide attempts, and the main explanatory variable was EVPs use. Of the 14,285 adolescents, 22.2%, 19.2%, and 58.8% were current, former and never users of EVPs, respectively. Controlling for other factors, current users of EVPs were significantly more likely to report having symptoms of depression (AOR = 1.82, 95% CI = 1.58-2.09), having suicidal ideation (AOR = 1.55, 95% CI = 1.30-1.86), making a suicide plan (AOR = 1.62, 95% CI = 1.34-1.97), or attempting suicide (AOR = 1.75, 95% CI = 1.41-2.18) when compared to never users of EVPs. Gender moderated the association between EVPs use, symptoms of depression, suicidal ideation, and suicide plan. Racial minority identity, sexual minority identity, sexual violence victimization, victim of school and cyberbullying, alcohol use, and cigarette smoking were all significantly associated with depression and suicidal behaviors. Study findings support the association between EVPs use and adolescent mental health. Future studies that employ longitudinal designs may offer more insight into the mechanisms underlying this association.

E-cigarettes and non-suicidal self-injury: Prevalence of risk behavior and variation by substance inhaled

BACKGROUND

Nicotine and cannabis inhalation through vaping or electronic delivery systems has surged among young adults in the United States, particularly during the coronavirus disease pandemic. Tobacco and marijuana use are associated with select adverse mental health outcomes, including symptoms of major depressive disorder and suicidal behaviors. Given the need for addiction specialists to treat problematic substance use with an integrated approach, the association between non-suicidal self-injury (NSSI) and use of e-cigarettes, tobacco, marijuana, and alcohol was examined among a diverse sample of college students.

METHODS

Healthy Minds Study data from 47,016 weighted observations, collected from college students in the 2018-2019 academic year, was used to explore associations between NSSI-related behaviors and past 30-day use of a vaping product (nicotine or marijuana). These relationships were assessed among those using vaping products only, and then among individuals using vaping products and alcohol, conventional cigarettes, and/or marijuana. Hierarchical logistic regression models estimating the relationship between vaping and NSSI were computed to adjust for the effects of demographic factors, symptomatology of psychiatric disorders, and concurrent use of other substances.

RESULTS

A fifth (22.9%) of respondents disclosed past 12-month NSSI; they were significantly more likely to screen positive for depression or anxiety compared to young adults without NSSI. Rates of using vaping products, conventional cigarettes, marijuana, or other substances were higher among students with NSSI even after controlling for potential cofounders. Additionally, students who used a THC-based liquid in their e-cigarettes were more likely to endorse NSSI in comparison to those who used "just flavoring." However, young adults who vaped were less likely to disclose frequent NSSI-related behaviors than their peers who did not vape.

CONCLUSIONS

These findings revealed an association between past 12-month NSSI and past 30-day vaping in a sample of young adults. Further surveillance among college populations and examination of potential sociodemographic confounders is necessary to confirm these findings and advance the substance use and addiction field.

Association of heated tobacco product use and secondhand smoke exposure with suicidal ideation, suicide plans and suicide attempts among Korean adolescents: A 2019 national survey

INTRODUCTION

The consumption of heated tobacco products (HTPs) is increasing among adolescents worldwide. Although suicide and HTP use are linked, the association between suicide-related behavior, HTP use, and indirect smoking exposure are not yet properly studied. This study examined the association of HTP use and exposure to secondhand smoke (SHS) with suicidal ideation, suicide plans, and suicide attempts among South Korean adolescents.

METHODS

Data from 57303 respondents (95.3% response rate) were obtained from the 2019 Korean Youth Risk Behavior Web-based Survey. Chi-squared tests and multivariable logistic regression analyses were used to examine the association of HTP use and SHS exposure with suicidal ideation, suicide plans, and suicide attempts among adolescents. Multivariable logistic regression analyses included: Model 1, which was adjusted for demographic characteristics such as sex, school type, perceived school performance, economic status, and residence type; and Model 2, which was adjusted for demographics, depression, and drug use.

RESULTS

The risk of suicidal ideation was 1.37 (95% CI: 1.10–1.70) and 1.44 (95% CI: 1.18–1.75) times higher among HTP users who were exposed to SHS at home and at public places, respectively, compared to non-users. The risk of suicide attempts was 1.88 (95% CI: 1.37–2.57), 1.45 (95% CI: 1.63–2.00), and 2.21 (95% CI: 1.63–3.00) times higher among HTP users exposed to SHS at home, school, and at public places, respectively.

CONCLUSIONS

HTP use, and SHS exposure are likely indicators of risk behaviors. Our findings suggest possible directions for initiating, implementing, and evaluating programs and services to monitor HTP use and SHS exposure among Korean adolescents.

Emotional symptoms and sensation seeking: Implications for tobacco interventions for youth and young adults

INTRODUCTION

Although emotional symptoms and sensation seeking are recognized as important risk factors for tobacco use among youth and young adults, to date, their joint influence on tobacco use has not been examined.

METHODS

Data used in this study are from the Texas Adolescent Tobacco and Marketing Surveillance study, a population-based cohort. At baseline, in 2014, participants were in the 10th grade. Mixed-effects logistic regression models examined associations between emotional symptoms and sensation seeking in 2014 and odds of past 30-day cigarette and e-cigarette use in 2018. Interactions between emotional symptoms and sensation seeking were examined to assess whether one modifies the effect of the other on cigarette and e-cigarette use.

RESULTS

After adjusting for age, sex, race/ethnicity, school type, and ever use of cigarettes or e-cigarettes at baseline, adolescents with high emotional symptoms (AOR_cig=1.97; 95% CI:1.07–3.60, and AOR_e-cig=1.68; 95% CI: 1.06–2.66) and with high sensation seeking tendencies (AOR_cig=2.05; 95% CI: 1.03–4.10, and AOR_e-cig=1.68; 95% CI: 1.02–2.76) had significantly higher odds of past 30-day cigarette and e-cigarette use four years later compared to adolescents with low emotional symptoms and low sensation seeking tendencies. The interaction was significant (p=0.01) for e-cigarette use only; among low sensation seekers, adolescents who reported high levels of emotional symptoms were at increased risk for past 30-day use (AOR_e-cig=3.43; 95% CI: 1.38–8.51), and among adolescents with low emotional symptoms, high sensation seekers were at increased for risk for past 30-day use (AOR_e-cig=3.50; 95% CI: 1.54–7.91).

CONCLUSIONS

It is important for tobacco use prevention programs to consider both behavioral risk factors – sensation seeking and emotional symptoms – in an integrative way, to target high risk subgroups and thereby increase the efficacy of existing effective intervention strategies in order to curb tobacco use among youth and young adults.

Association of Cigarette Type Initially Smoked With Suicidal Behaviors Among Adolescents in Korea From 2015 to 2018

IMPORTANCE

Assessment of whether past electronic cigarette (e-cigarette) use or initiating smoking with e-cigarettes is associated with suicidal behaviors among adolescents is needed to inform future research and public health interventions.

OBJECTIVE

To evaluate the association between starting smoking with e-cigarettes or conventional cigarettes and suicidal behaviors among Korean adolescents.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study analyzed data on adolescents in grades 7 through 12 who participated in the nationwide Korea Youth Risk Behavior Web-Based Survey between 2015 and 2018.

EXPOSURES

Type of cigarette initially smoked: electronic or conventional.

MAIN OUTCOMES AND MEASURES

Multiple logistic regression analysis was performed to examine the association between initial cigarette type and suicidal behaviors, including suicidal ideation and suicide planning and attempts. All participants completed questionnaires about their history of suicidal behavior and were categorized into groups according to the type of cigarette used at initiation of smoking and any subsequent change (or lack of change) in the type of cigarette used.

RESULTS

A total of 255 887 Korean adolescents (51.2% male; mean (SD) age, 15.0 [1.8] years) were included in the primary analysis. Among 131 094 male adolescents, 3310 boys (2.5%) initially used e-cigarettes and 27 368 boys (20.9%) initially used conventional cigarettes. Among 124 793 female adolescents, 952 girls (0.8%) initially used e-cigarettes and 9296 girls (7.4%) initially used conventional cigarettes. Of those who initially used e-cigarettes, 178 of 3310 boys (5.4%) and 134 of 952 girls (14.1%) attempted suicide. Of those who initially used conventional cigarettes, 946 of 27 368 boys (3.5%) and 911 of 9296 girls (9.8%) attempted suicide. Adolescents who initially used e-cigarettes had a higher risk of suicidal behaviors, including suicide planning (boys: adjusted odds ratio [AOR], 1.63 [95% CI, 1.40-1.89]; P < .001; girls: AOR, 1.55 [95% CI, 1.23-1.95]; P < .001) and suicide attempts (boys: AOR, 1.55 [95% CI, 1.28-1.87]; P < .001; girls, AOR, 1.64 [95% CI, 1.29-2.10]; P < .001) compared with those who initially used conventional cigarettes. Changing from e-cigarettes to conventional cigarettes was associated with a higher risk of suicide attempts among both boys (AOR, 1.89; 95% CI, 1.39-2.57; P < .001) and girls (AOR, 2.36; 95% CI, 1.53-3.64; P < .001) compared with changing from conventional cigarettes to e-cigarettes.

CONCLUSIONS AND RELEVANCE

In this study, the initial use of e-cigarettes vs conventional cigarettes was associated with suicidal behaviors among adolescents. In future research on the association of e-cigarette use with adolescent mental health and interventions for suicide prevention, the type of cigarette initially used and changing the cigarette type should be considered.

Investigation of E-Cigarette Smoking Model with Mittag-Leffler Kernel

Smoking is the most lethal social poisoning event. The World Health Organization defines smoking as the most important preventable cause of disease. Around 4.9 million people worldwide die from smoking every year. In order to analysis this matter, we aim to investigate an e-cigarette smoking model with Atangana-Baleanu fractional derivative. We obtain the existence conditions of the solution for this fractional model utilizing fixed-point theory. After giving existence conditions, the uniqueness of the solution is proved. Finally, to show the effect of the Atangana-Baleanu fractional derivative on the model, we give some numerical results supported by illustrative graphics.

Associations between the Type of Tobacco Products and Suicidal Behaviors: A Nationwide Population-Based Study among Korean Adolescents

The relationships between multiple tobacco products, such as heated tobacco products (HTPs), electronic cigarettes (ECs), and combustible cigarettes (CCs), and suicide-related behaviors among adolescents have not been extensively researched. This study examined the associations between the type of tobacco products used and suicidal thoughts, plans, and attempts among Korean adolescents. Data from the 2019 Korea Youth Risk Behavior Web-Based Survey were analyzed, and participants included 57,069 individuals aged 13–18 years. A multivariable logistic regression analysis was performed. Of the total participants, 13.0%, 4.0%, and 2.9% reported suicidal thoughts, suicidal plans, and suicidal attempts, respectively. After adjusting for confounding variables, all tobacco product users showed a greater likelihood of having suicidal behavior. However, compared with never users, dual users of CCs and HTPs were not significantly associated with having suicidal thoughts and attempts. Among tobacco product users, dual users of ECs and HTPs and triple users of CCs, ECs, and HTPs showed a greater likelihood of having suicidal behavior. Considering the prevalence of suicide and the increasing trend of using multiple tobacco products among Korean adolescents, tobacco control policies should monitor the effects of different products.

Associated factors for depression, suicidal ideation and suicide attempt among asthmatic adolescents with experience of electronic cigarette use

INTRODUCTION

While electronic cigarette (EC) use is rapidly increasing among asthmatic adolescents, little is known about the links between EC use and depression or suicidality. We assessed associated factors for depression and suicidality in asthmatic adolescents with experience of EC use.

METHODS

We analyzed the data from the 11th to 13th Korea Youth Risk Behavior Web-based Surveys, which were completed from 2015 to 2017. Data were obtained from a stratified, multistage, clustered sample. Students supplied ‘yes or no’ answers to questions about previous asthma diagnosis by a doctor. Associated factors for depression and suicidality were evaluated by logistic regression models after controlling for potential confounding factors. We targeted 203336 adolescents, and 195847 completed the survey.

RESULTS

The proportion of asthma among the respondents was 8.9%. The rate of experience of EC use was higher among asthmatic respondents than non-asthmatic respondents (10.3% vs 8.6%). Asthmatic respondents with experience of EC use had a much higher proportion of negative mental health states including depression and suicidality than subjects without EC experience. In our adjusted models, perception of stress was most strongly associated with depression (adjusted odds ratio, AOR=4.79; 95% CI: 4.12–5.58), and perception of unhappiness was most strongly associated with suicidal ideation (AOR=5.24; 95% CI: 4.51–6.09) and suicide attempt (AOR=4.37; 95% CI: 3.36–5.69).

CONCLUSIONS

Many Korean asthmatic adolescents with experience of EC use report relatively high depression and suicidal behaviors. A multidisciplinary approach, including psychological help, may be required to prevent suicide among this population, especially those who report associated factors.

Electronic cigarettes: Emerging trends and research hotspots

INTRODUCTION

Research on electronic cigarettes is an emerging field, with the number of articles in this field noted to have grown exponentially over recent years. We used a bibliometric analysis method (co-word analysis) to analyze the emerging trends and research hotspots in this field.

METHODS

Publication data on electronic cigarettes from 2010 to 2018 were retrieved and downloaded from the PubMed database. Theme trends and knowledge structures were analyzed on the relevant research fields of electronic cigarettes by using a biclustering analysis, strategic diagram analysis, and social network analysis methods. Research hotspots were extracted and compared from three periods.

RESULTS

Core topics that have continuously develop between the years 2010 and 2018 include: tobacco use cessation devices; tobacco products; tobacco use cessation devices/adverse effects; smoking prevention and adverse effects; electronic nicotine delivery systems/economics; and public health. Some currently undeveloped topics that could be considered as new future research directions include: tobacco use disorder/therapy; tobacco use disorder/epidemiology; students/psychology; students/statistics and numerical data; adolescent behavior/psychology; nicotine/toxicity; nicotinic agonists/administration and dosage; and electronic nicotine delivery systems/legislation and jurisprudence.

CONCLUSIONS

Results suggest that some currently immature topics in strategic coordinates and emerging hotspots in social network graphs can be used as future research directions.