Vaping and teens: Review links it to smoking, asthma and mental health risks

An umbrella review has been published in the journal Tobacco Control (BMJ) - a synthesis of 56 previously published reviews (52 systematic and 4 umbrella) on the harm of vaping in children and adolescents. The authors found a strong link between e-cigarette use in adolescence and subsequent smoking initiation, as well as a range of adverse outcomes - from respiratory problems (including asthma) to worsening mental health and an increased risk of alcohol and cannabis use. The publication was posted online on August 19, 2025.

Background of the study

Over the past 10-15 years, e-cigarettes have gone from being a “niche novelty” to the most widely used nicotine product among adolescents in many countries. In the WHO European Region, the proportion of current (past 30-day) vaping among 13- to 15-year-olds varies greatly between countries and locations, rising to very high values in some studies of urban samples; according to regional estimates, millions of adolescents try or regularly use electronic devices. The US Centers for Disease Control emphasizes that there are no safe tobacco products for children and non-smoking youth, and e-cigarettes are no exception. Against this background, interest in “umbrella” and systematic reviews has grown: they allow disparate data on prevalence and risks to be collected into a single picture.

A key public question is whether vaping has long-term consequences for adolescents and a “gateway effect” to smoking. At the observational level, many meta-analyses have documented a stable association between vaping and subsequent smoking initiation, but the interpretation is controversial: some researchers point to possible causality (“gateway”), others to a “general propensity to risk,” when the same adolescents are a priori more likely to try any psychoactive substances (the common liability model). Therefore, it is important to read the assessments of such reviews together with an analysis of the quality of primary studies and sensitivity to confounding factors.

At the same time, there is a growing body of literature on health outcomes in young people – primarily respiratory symptoms and asthma, but also associations with mental health and co-use of alcohol and cannabis. Umbrella reviews are useful here because they compare the findings of different teams and show where signals are repeated across studies and where they are based on weaker evidence (e.g., cross-sectional surveys and case series). At the same time, independent experts regularly remind us that most available studies are observational and of variable quality, so even strong associations cannot be automatically interpreted as causal – an argument for more rigorous prospective and quasi-experimental designs.

Finally, the balance of contexts is important: for adult smokers, e-cigarettes are seen as a less harmful alternative to cigarettes and a tool for quitting smoking, but for children and non-smoking adolescents, regulators and professional communities agree on one thing: vaping carries excessive risks without proven benefits. Hence the strengthening of measures to limit marketing and availability of devices to minors and a parallel demand for high-quality research that will help to separate the contribution of vaping from background factors and more accurately target prevention.

Design and scope: why this review is getting attention

The "umbrella" format is meta-on-meta: researchers do not mix primary studies, but analyze existing systematic reviews and meta-analyses published from 2016 to 2024 (most of them after 2020). This approach allows us to see where the results of different groups consistently coincide and where they diverge. A separate focus is on adolescents and young adults, as well as behavioral and medical outcomes that are often excluded from narrow reviews (for example, only about "does vaping light up smoking").

Key findings

A synthesis of data from 21 systematic reviews found a strong association between vaping and subsequent smoking initiation, with estimates ranging from +50% to 26-fold increased odds, with young vapers typically being around three times more likely to initiate smoking than their non-vaping peers. A synthesis of five reviews found a strong association with substance use, with the risk of progression to cannabis almost tripled to six-fold, alcohol around 4.5-6+ times, and binge drinking 4.5-7 times higher. In the respiratory system, the most consistent signals were for asthma, with a +20-36% increased risk of diagnosis and a +44% increased risk of exacerbations in vapers. There were also associations with trauma/burns, symptoms of mental distress, bronchitis/pneumonia, headache/dizziness/migraine, decreased total sperm count and oral problems - but for these items the evidence is weaker (surveys, case series).

What looks most convincing in the review:

• persistent associations “vaping → debut of smoking” in adolescents;
• parallel associations with alcohol and cannabis use;
• asthma signals (diagnosis and exacerbations).

Where the evidence is still flimsy:

• dental problems, headaches/migraines, bronchitis/pneumonia, decreased spermatogenesis - mainly based on low-level materials (cross-sectional surveys, case series);
• causal interpretation in general: most sources are observational studies.

Context: the scale of the phenomenon and why politicians care

The WHO has already called the rise in vaping among children “alarming”: the proportion of 15-16 year-olds using vapes in the European region varies from 5.5% to 41%. The authors of the review make a pragmatic conclusion: even with caveats about the quality of the data, the combination of relationships justifies restrictions on the sale and marketing of vapes to minors and measures against advertising attributes that are attractive to children.

Important caveats and criticism: don't confuse associations with causality

The review itself emphasizes: the "umbrella" assessment depends on the quality of the included reviews, and the lion's share of the primary data is observational, which means that it is impossible to make a categorical conclusion that "vaping causes X". This nuance was separately emphasized by independent experts from the Science Media Centre: in their opinion, most of the included systematic reviews are of low/critically low quality, and the statement of "causality" ("gateway effect") requires caution and is better tested on population trends (where in some countries the growth of vaping was accompanied by a decline in teenage smoking). Bottom line: there are many connections and they are strong, but the quality of evidence is uneven, some of the signals can be explained by a general tendency to risky behavior (common liability).

How to read the results without going overboard:

• “They start smoking 3 times more often” is about the average estimate of the association, not about a proven causal pathway;
• cross-sectional surveys do not answer the question "what came first - vaping or the problem";
• Prospective data are needed to draw conclusions about rare/long-term outcomes (eg, fertility).

What this means for schools, families and regulators - practical steps

• Policy and environment: marketing restrictions (including device/packaging design), age control of sales, counteraction to “viral” advertising on social networks are first-line measures. Some experiments show that unifying the design of disposable vapes reduces teenagers’ interest in trying them.
• Risk communication: explain that vaping is not safe for non-smokers and that in adolescents it carries a risk of transitioning to tobacco and other substance use; do not confuse it with smoking cessation aids for adults.
• Schools and parents: monitor new “trendy” devices and flavors, pay attention to respiratory symptoms, discuss real risks (asthma, injuries, mental health) and not just “nicotine addiction.”

What will science do next?

The authors and independent experts agree: what is needed are high-quality prospective cohorts and quasi-experimental designs, standardized definitions of exposure/outcomes, consideration of “general risk propensity,” and population trend analysis (what happens to all teens in a country when vaping availability/regulation changes). Only then can we disentangle the role of vaping from its confounding factors and understand who is harmed and how.

Research source: Vaping and harm in young people: umbrella review, Tobacco Control (online 19 August 2025), DOI: 10.1136/tc-2024-059219.