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An observational study published in PLOS Mental Health looks at mental health outcomes in teens who smoke or use e-cigarettes.
Prof Peter Hajek, Professor of Clinical Psychology, and Director of the Health and Lifestyle Research Unit, Queen Mary University of London (QMUL), said:
“There is not much novelty in this study. The findings add to the well-established link between mental health issues or other sources of stress, especially in childhood, and the use of psychoactive substances including nicotine.”
Prof Stella Chan, Charlie Waller Chair in Evidence-Based Psychological Treatment, University of Reading, said:
“This well conducted study has helpfully established robust evidence for a link between the use of cigarettes and vapes and symptoms of depression and anxiety in adolescents in the US. As acknowledged by the authors, the cross-sectional nature of the data cannot point towards causal relationships. It is therefore impossible to determine from this study if the use of tobacco increases the risk for mental health problems; or that adolescents with mood difficulties use tobacco as a coping strategy; or if a bit of both. Future research can also investigate differences between gender groups, those with neural divergent conditions, those belonging to minority or vulnerable groups such as LGBT+ , in care system, or justice system, to understand the effects of tobacco use in further details in order to inform support and intervention.”
Dr Jasmine Khouja, Senior Research Associate in the Tobacco and Alcohol Research Group, University of Bristol, said:
“This study design is not appropriate to address the research question. The study measures whether adolescents who have ever tried a “tobacco product” (even just once) are more or less likely to have some symptoms of anxiety or depression. It does not measure whether regularly using e-cigarettes or smoking causes depression or anxiety. Although the number of young people who used e-cigarettes more than once or twice is not reported, the majority of this group is likely made up of young people who vaped once or twice to give it a try. Therefore, the study measures whether people with anxiety and depression symptoms are more likely to have experimented with potentially risky products. This is not discussed in the limitations, which is concerning because the authors should be aware that the measure is not appropriate for this question.
“The study does not adequately account for other factors that could be driving this link, and it is cross-sectional, meaning that the mental health symptoms could have preceded the vaping experimentation. The authors state that nicotine could be a mechanism by which vaping could cause depression and anxiety, but they did not ascertain whether the products contained nicotine or not.
“It is important to note that although the authors describe e-cigarettes as tobacco products, e-cigarettes do not contain tobacco, and using e-cigarettes is not considered tobacco use.
“This study alone does not add much to our understanding of the relationship between vaping, smoking, and mental health. Much more research (with a more appropriate study design) is needed before we can determine whether vaping causes poor mental health.”
Dr Johnathan Livingstone-Banks, Lecturer & Senior Researcher in Evidence-Based Healthcare, Nuffield Department of Primary Care Health Sciences, University of Oxford, said:
“This study finds a correlation between ever trying cigarettes or vapes and reporting depression or anxiety, but as the authors note, it doesn’t show that one causes the other. It could just as easily be that young people with poor mental health are more likely to experiment. However, that does not mean that this correlation shouldn’t be taken seriously, and there is evidence in adults that quitting smoking can improve mental health.
“In the US, vapes are classed as tobacco products. But it’s worth clarifying: while they usually contain nicotine, they don’t contain any tobacco. In the UK, they’re not classified as tobacco products.
“This survey counts anyone who has ever used a vape or cigarette, even just once, as a user. That’s potentially misleading, especially when it comes to ‘dual use’. Someone who tried a vape once and a cigarette once, perhaps years apart, would be counted as dual users. Without more detailed data, we can’t tell whether these young people were actual users or just experimenting. The sample probably includes a mix of both.”
Dr Lion Shahab, Chartered member of the British Psychological Society, said:
“This study analysed cross-sectional data from the US National Youth Tobacco Survey to investigate the association of cigarettes and e-cigarette use in youth with self-reported depression and anxiety symptoms. The results show that exclusive cigarette and exclusive e-cigarette use, as well as co-use of both products was associated with higher depression and anxiety levels than not using either. Tobacco use has a well-established bidirectional relationship with mental health such that mental health symptoms predict later smoking and smoking leads to deterioration in mental health symptoms. This study shows that a similar relationship may exist with e-cigarette use.
“However, there are several caveats that need to be considered when interpreting these findings. First, as all measurements were taken at the same time, it is not clear whether e-cigarette use preceded poorer mental health symptoms or whether poorer mental health symptoms preceded e-cigarettes use, or whether there is evidence of an effect in both directions. This can only be assessed in a longitudinal cohort study where timelines of what occurs first (e-cigarette use or deterioration in mental health symptoms) can be clearly established.
“Due to the cross-sectional nature of this study, it is therefore as likely that adolescents who have experienced psychological stress or mental health problems may be more likely to start vaping as it is that prior vaping leads to later poor mental health outcomes. Second, as for most epidemiological studies, there is a risk that important factors that influence both e-cigarette use and mental health symptoms were not controlled for. For instance, this study did not account for familial history of mental health problems, which may – in part – explain the observed association.
“Lastly, the study used a relatively crude measure of e-cigarette use, which was defined ‘ever e-cigarette only use’. This category lumps together adolescents who may have used an e-cigarette once or twice with youth who vape daily, which is unhelpful. It is unlikely that very occasional e-cigarette use will have lasting effects on mental health. Future work would benefit from investigating whether the frequency of vaping and nicotine content in vapes has a dose-response relationship with mental health symptoms. Notwithstanding these issues, this study highlights the need to examine the effects of vaping in youth, not only in terms of potential physical health but also mental health.”
‘Mental health outcomes associated with electronic cigarette use, combustible tobacco use, and dual use among U.S. adolescents: Insights from the National Youth Tobacco Survey’ by Abdulhay et al. was published in PLOS Mental Health at 19:00 UK time on Wednesday 23th July.
DOI: 10.1371/journal.pmen.0000370
Declared interests
Dr Jasmine Khouja None
Prof Peter Hajek None
Prof Stella Chan None
Dr Jonathan Livingstone-Banks No financial conflicts – I’ve never received funding from industry. I’m a tobacco control researcher at the University of Oxford and I’m an author of numerous academic papers on smoking and e-cigarettes, including the Cochrane reviews on e-cigarettes for smoking cessation and interventions for vaping cessation.
Dr Lion Shahab None
For all other experts, no reply to our request for DOIs was received.