Adolescence is a critical window for the development of mental health. Longitudinal research has shown that youth with poor mental health are at a greater risk for adverse outcomes in adulthood [1]. Despite this concern, there has been little progress in addressing mental health concerns for this age group. For example, in 2023, 40% of high school students in the United States (U.S.) had reported experiencing feelings of sadness and hopelessness, a measure frequently used in national surveillance systems to screen for depressive symptoms [2]. Over the past decade, the percentage of high school students reporting feelings of sadness of hopelessness has increased among both male and female students [2]. Among female students, rates of feeling sad or hopeless rose from 39% in 2013 to 53% in 2023, while among male students, the rates increased from 21% to 28% during the same period [2].

In 2023, suicide was the second leading cause of death for youth aged 10 – 14 and those aged 15–24 [3]. In 2023, 20% of high school students seriously considered attempting suicide, 16% made a suicide plan, and 9% attempted suicide, rates that have all increased compared to 2013 [2]. Depression and anxiety are among the leading causes of illness and disability in adolescents, and both conditions are associated with suicidal behavior [4–6]. According to data from the National Health Interview Survey – Teen collected from July 2021 – December 2023, an estimated 17.8% of U.S. adolescents aged 12–17 reported symptoms of depression in the past two weeks, and 19.7% reported symptoms of anxiety [7].

Tobacco use and mental health challenges are known to have a complex, bidirectional relationship. A longitudinal study conducted in a large Midwestern city in the U.S. followed 262 girls aged 11–20 years old and found that higher levels of conventional cigarette smoking predicted increases in depressive symptoms over time, however, depressive symptoms did not predict smoking [8]. Another longitudinal study conducted in Southern California found that adolescents with higher depressive symptoms in 6^th grade were more likely to initiate smoking by 8^th grade [9]. Additionally, a study using data from the National Longitudinal Study of Adolescent to Adult Health (Add Health) identified a bidirectional association between conventional cigarette use and anxiety during adolescence [10]. This study found that adolescents who smoked more at baseline reported increased anxiety symptoms, and baseline anxiety symptoms also predicted greater cigarette use at follow up [10].

The rise of electronic cigarettes (e-cigarettes) has shifted tobacco consumption patterns, particularly among youth, who continue to be drawn to e-cigarettes for their perceived safety, discreet use, high nicotine content, and appealing flavors [11–14]. In 2024, approximately 5.28 million (19.0%) U.S. middle and high school students reported ever using any tobacco product, and 2.25 million (8.1%) students reported currently using any tobacco product [15]. E-cigarettes have remained the most used tobacco product since 2014, with 43.6% of ever e-cigarette users reporting current use [15,16]. The dual use of e-cigarettes and combustible tobacco products (CTP), such as conventional cigarettes, is also common, often leading to greater nicotine dependence and decreased motivation to quit [17–19].

Understanding the relationship between adolescent tobacco use and mental health in adolescents is particularly important as adolescence is a critical developmental period during which many health-related risk-taking behaviors begin [4]. Risk taking behaviors such as engaging in tobacco use are often unhealthy coping strategies for managing emotions and can negatively impact adolescent mental health [4]. Previous studies have proposed that mental health may be affected differently with e-cigarettes compared to CTP since e-cigarettes deliver nicotine without combustion, expose them to fewer harmful chemicals, and are used under different social and psychological contexts [20,21]. However, much of the current literature still focuses primary on conventional cigarettes, and there remains a significant gap in research examining how mental health is associated with e-cigarette use and dual use, particularly in comparison to conventional cigarette users or non- users [21].

Therefore, the aim of this study is to address this research gap by examining the association between different tobacco use profiles (e-cigarette, CTP, and dual use) and mental health outcomes (depression, anxiety, and overall psychological distress) among a nationally representative population of U.S. middle and high school students.

Of the 93,429 middle and high school students initially included in the NYTS sample from 2021-2023, 70,773 completed the student questionnaires. After further excluding 10,701 participants who did not complete the PHQ-4 or had incomplete answers on tobacco use-related questions, a total of 60,072 (62.4%) participants were included in the analysis (Fig 1). A comparison of participants who were included in the analysis (n = 60,072) versus those who were excluded (n = 10,701) is provided in S2 Table. Participants who were excluded were more likely to be part of the 2023 cycle, in middle school, male, Black or Hispanic, unsure about their sexual orientation, from households with tobacco use, using social medial less frequency, and achieving lower grades, all with P < 0.001. However, given the large sample size, the magnitude of difference between excluded and included participants were minimal.

Descriptive statistics across the tobacco smoking categories are presented in Table 1. Among the surveyed participants, there were 2,306 who had ever CTP-only use (3.61%), 5,686 had ever e-cigarette-only use (9.94%), 4,605 had ever dual use (7.80%), and 47,475 who had no use (78.63%). Significant differences in participant characteristics across tobacco smoking categories were observed in school level, sex, race/ethnicity, sexual orientation, tobacco use in the household, social media usage, and average school grades, all with p-values < .001. Compared to middle school students, high school students had higher rates of ever e-cigarette only use (4.6% vs. 13.9%) and ever dual use (3.1% vs. 11.2%). Compared to heterosexual participants, sexual minority youth had a higher prevalence of ever e-cigarette only use (9.9% vs. 13.1%) and ever dual use (7.5% vs. 14.1%). Social media usage also correlated with tobacco use. Compared to participants who never used social media, those who used social media for 3 or more hours per day reported great use for ever e-cigarette use (9.9% vs. 12.1%) and ever dual use (7.5% vs. 12.1%). Finally, adolescents with lower academic performance had higher rates of tobacco use, with ever dual use most common among those with mostly F’s (19.2%) compared to those with mostly A-B’s (6.5%).

The prevalence of depression and anxiety symptoms across different tobacco smoking categories is presented in Fig 2. Among adolescents who were ever dual users, 43.4% reported symptoms of depression and 45.2% reported symptoms of anxiety. For adolescents who were ever e-cigarette-only users, 35.9% reported symptoms of depression and 40.5% indicated symptoms of anxiety. Adolescents who ever used CTP-only reported similar rates (35.6% for depression, 38.4% anxiety). Adolescents who did not use any tobacco reported the lowest prevalence, with 21.8% reporting depression symptoms, and 26.4% reporting anxiety symptoms.

Unadjusted OR and aOR for the association between tobacco smoking categories and symptoms of depression, anxiety, and overall psychological distress are presented in Table 2. The adjusted analysis revealed that compared to adolescents with no use, adolescents with ever CTP-only use had increased odds of depression (aOR = 1.52, 95% CI: 1.29-1.78), anxiety (aOR = 1.39, 95% CI: 1.18-1.63), and psychological distress (aOR = 1.43, 95% CI: 1.24-1.65). Adolescents with ever e-cigarette-only use had even higher odds of depression (aOR = 1.67, 95% CI: 1.50-1.85), anxiety (aOR = 1.48, 95% CI: 1.34-1.65), and psychological distress (aOR = 1.63, 95% CI: 1.49-1.78). Finally, adolescents with ever dual use exhibited the greatest risk, with aORs of 1.90 (95% CI: 1.69-2.14) for depression, 1.58 (95% CI: 1.40-1.78) for anxiety, and 1.75 (95% CI: 1.58-1.94) for psychological distress (Table 2). Across all three mental health outcomes, the aORs were slightly lower compared to the unadjusted estimates, indicating that part of the association was explained by covariates. However, all associations remained statistically significant after adjustment. The full models, including associations with demographic factors, are reported in the supplementary material (S3, S4, S5 Tables).

Results from this study highlight how tobacco use, particularly ever e-cigarette-only use and ever dual use, is associated with mental health conditions among adolescents. Our results demonstrate that, compared to adolescents who have never used any tobacco product, adolescents who have ever used e-cigarettes, CTP, and especially both, had higher odds of experiencing symptoms of depression, anxiety, and overall psychological distress. These associations remained statistically significant even after adjusting for demographic and behavioral covariates.

Results from this study are consistent with the limited studies that have explored the relationship between tobacco use, including e-cigarette use, and mental health. For example, a study using data from the 2019 Texas Adolescent Tobacco and Marketing Surveillance study found that youth with negative mental health had significantly higher odds of using tobacco products, including e-cigarettes [26]. Similarly, a study conducted among Thai adolescents found that those who had ever used e-cigarettes were more likely to show signs of depression, even if they were not currently using that product [27]. A previous longitudinal study among high school students in Los Angeles, California examined the bidirectional association between tobacco use, including e-cigarettes and dual use, and depressive symptoms [20]. This study found that higher depressive symptoms at baseline significantly increased the odds of initiating tobacco use at follow up [20]. Additionally, e-cigarette use over time was associated with a greater increase in depressive symptoms, however this was not statistically significant [20].

In addition to just experiencing poor mental health, e-cigarette use has also been associated with suicidal behaviors among youth. A study using data from the 2017 and the 2019 Youth Risk Behavior Survey in the U.S. revealed that current users of electronic vaping products had significantly greater odds of suicidal ideation, suicide plans, and suicide attempts compared to never users [28]. Additionally, a nationally representative study of Korean adolescents further showed that e-cigarette and dual users were both about 6 times more likely to have attempted suicide and conventional cigarette only users were around 2 times more likely to attempt suicide than non-users [29].

The observed associations between different tobacco use products and mental health symptoms may be explained by several mechanisms. Both e-cigarettes and CTP differ in their delivery mechanisms, however, both methods expose adolescents to nicotine, a highly addictive substance [30]. Adolescents who develop a dependency to nicotine, may experience disruptions in brain development, potentially affecting mood regulation, permanent damage to memory, cognitive function, and emotional control [31–34].

In a nationally representative sample of middle and high school U.S. students, adolescents who used tobacco were more likely to report negative mental health conditions compared to non-users. While causality cannot be determined, the results from this study showed that all forms of tobacco use were significantly associated with mental health issues. There is a need to continue promoting mental health support and implementing tailored interventions to combat all forms of tobacco use among adolescents.