E-Cigarettes: Godsend for Smoking-Cessation or Trojan Horse?

The relative risks and benefits of e-cigarettes for public health are a subject of ongoing controversy. Some highlight their potential dangers, such as rapid uptake by adolescents, many of whom are nicotine naïve when they start. Others argue that they are a healthier alternative to cigarette smoking and promote quitting, the benefits outweighing the risks.

Recent research in Addiction published on May 11, 2022, found that e-cigarette use may have adverse effects on several mental health measures, supporting arguments against them. So, in the end, what should we think about them, and are they good or bad? And what should we tell our patients and clients?

E-Cigarettes as Smoking Cessation Agents

The Pros:

Proponents claim that e-cigarettes help people quit smoking and argue they are significantly less toxic than combustible cigarettes. In addition, some studies have found that it may be easier to stay off cigarettes with these products than with more standard approaches to quitting, like nicotine replacement therapy.

The Cons:

On the other hand, when other factors are considered, e-cigarette use may not measure up compared to other more traditional approaches for quitting smoking. For example, most people who use e-cigarettes to quit smoking end up transitioning from one nicotine delivery system to another, albeit less toxic, one.

Second, e-cigarettes might only promote smoking cessation if they are used in the context of a structured clinical trial but not in the real world. Third, in smokers with no desire to quit, e-cigarettes may even promote more cigarette smoking, in part related to the fact that nicotine levels are much higher in vaping products than in traditional cigarettes.

For these reasons and others, the U.S. FDA has not approved them as smoking cessation agents, concluding that “there is inadequate evidence to conclude that e-cigarettes…increase smoking cessation”. Existing strategies for smoking cessation, like nicotine replacement and medications like bupropion and varenicline, work equally well or better.

Cigarettes and Mental Health: Background

The evidence that e-cigarettes have the potential to promote health via their ability to promote quitting smoking is, therefore, still weak. Although reportedly e-cigarettes are better than combustible cigarettes from the standpoint of physical health, what about their relative effects on mental health?

Before answering this question, first, we will review some background on what we know about the adverse effects of cigarette smoking on mental well-being.

Smoking Causes Depression and Anxiety

People who smoke are more likely to have depression and anxiety, and it’s not just because people with mood issues take up smoking to self-medicate. Rather, cigarette smoking itself causes the link between them, research finds.

Studies on adolescents' and adults' negative moods caused by smoking have concluded that the cigarettes are to blame. A recent sweeping meta-analysis summarizing 102 studies representing over 169,500 participants of all ages concluded that quitting smoking improves mental health, including anxiety, depression, and psychological quality of life.

Studies in animal models have also found that nicotine causes depression. For example, chronic exposure to nicotine in adolescent rodents induces later depressive-like behavior.

Cigarettes are a Gateway Drug

The “gateway hypothesis” states that exposure to tobacco and nicotine can pave the way for adolescents to try and become regular users of “harder” drugs like cannabis, alcohol, and illicit drugs. Numerous studies have supported this hypothesis: nicotine and tobacco use precedes the use of alcohol, cannabis, and other illicit drugs across populations and samples, and smoking cigarettes increases the risk of using other drugs later on.

Animal studies also show that nicotine primes the reward system, and the use of nicotine leads to more generalized drug-seeking later on. For example, rats exposed to nicotine first later self-administer more methamphetamine, cocaine, and alcohol than unexposed rats.

Converging evidence indicates that all addictive drugs, including nicotine, act similarly on brain function to reinforce their continued use and ultimately lose control. That’s why when someone develops an addiction to one drug, it is easier to develop a problem with another: they all act on the same reward pathways.

Adolescence is a particularly vulnerable period for the priming effect of cigarettes due to more sensitive reward systems, more robust reward learning, and susceptibility to damage from direct toxic effects on key brain functions such as impulse control.

The Recent Study: Impacts of E-Cigarettes on Mental Health and Substance Use

So do e-cigarettes affect mood and risk of using other addictive substances in the same way that combustible cigarettes do, or are they somehow less toxic, mirroring the patterns we see for physical health? A recent publication reports on their findings to answer this question.

Previous to this study, it was known that e-cigarettes might cause sleep difficulties and that they were associated with anxiety, depression, and the use of other addictive substances. However, it was still unresolved whether e-cigarette use causes anxiety, depression, and other substance use or whether it was just that people with mood and substance use used more e-cigarettes.

In 2015, an e-cigarette minimum legal age law was passed in Canada in some, but not all, provinces. Previous research has shown that these kinds of laws reduce the use of e-cigarettes.

This provided researchers with a naturalistic experimental environment to determine what reductions in e-cigarette access and use might do to mental health and substance use.

To learn more, researchers measured the impacts of this law on self-reported mood disorders, anxiety disorders, peer relationships, and other substance use, including cannabis, illicit drugs, and cigarettes. Almost 80,000 youths ages 15-24 were included, and two subgroups were examined with different age ranges (15-18 and 15-24).

After the laws were put into effect, the risks of mood disorders went down by 1.9 and 2.6 percentage points, depending on the group examined. The risks of anxiety disorders went down by 3.6 percentage points in the larger group. E-cigarette use increased the likelihood of mood and anxiety disorders by 44 percent and 37 percent, respectively. In provinces where e-cigarette use was restricted, there was a reduction in the use of cannabis and illicit drugs, and people reported better peer relationships.

In the discussion, the authors also highlight how the increased risk of transitioning to cannabis, in particular, might be partially attributable to the fact that both are consumed through vaping.

In Conclusion

These findings indicate that e-cigarettes, like traditional cigarettes, might increase depression, anxiety, and other addictive substance use in adolescents and young adults. The results of this study would indicate that it’s the nicotine that’s the problem, not just tobacco.

How much governments should restrict e-cigarette use is an ongoing subject of debate. However, until consensus is reached, more studies into the long-term effects on mental health are needed, too, especially in younger people. Furthermore, how e-cigarettes affect uptake and risk of initiation of other substances, including traditional cigarettes, needs further investigation.

In the meantime, public health officials should continue to prioritize reducing access to teens and young adults via banning certain flavors, increasing penalties for illegal sales, and potentially raising the minimum age. And we should encourage our patients to be very cautious, indeed.