The Unhealthy Association Between Smoking, Vaping, and Other Drug Use

The use of tobacco products and nicotine products such as e-cigarettes is highly addictive, and tobacco products have numerous adverse health effects, including cancer, cardiovascular disease, obstructive pulmonary disease, and premature cognitive decline.^1,2 E-cigarettes were developed as a safe alternative to tobacco products, but there is accumulating evidence that e-cigarettes also have adverse health effects. The use of tobacco products is quickly declining in the Americas, Europe, and Africa.³ However, tobacco use has been declining slowly in other regions, such as the Western Pacific Region.³ Although e-cigarettes can help people quit smoking tobacco, they have also led to a very large increase in nicotine use in adolescents and adults.⁴

Tobacco smoke contains thousands of compounds, and some of these compounds could potentially enhance the rewarding properties of nicotine.⁵ In this issue, Kim et al. demonstrate that the reinforcing and neurochemical properties of nicotine and whole cigarette smoke condensate are similar.⁶ This work suggests that the reinforcing properties of tobacco products are primarily mediated via nicotine. This might explain the appeal of e-cigarettes, which deliver nicotine but not the other tobacco smoke components. The use of tobacco and nicotine products may also affect the effects of drugs of abuse, and people who use drugs of abuse are more likely to smoke or vape. For example, it has been shown that people who use cannabis are more likely to start smoking cigarettes, are less likely to try quitting, and are more likely to relapse.⁷ The articles in this issue explore the co-use of tobacco products and nicotine products with other drugs of abuse. Several articles explore the interactions between nicotine aerosol and other drugs of abuse. People who use opioids such as the synthetic opioid methadone are more likely to smoke than people in the general population.⁸ Avelar et al. investigated whether the co-use of opioids and nicotine might be more rewarding than using nicotine alone.⁹ Their study with adult mice showed that co-administration of morphine and nicotine is not more rewarding in a condition place preference test than administering nicotine or morphine alone. Furthermore, pretreatment with morphine reduced nicotine aerosol self-administration in mice. Therefore, it is unlikely that people co-use nicotine and opioids because it is more rewarding than using these compounds alone.⁹ The co-use of alcohol and nicotine is extremely common, and high schoolers who vape are more likely to drink alcohol.¹⁰ Ruffolo et al. investigated if exposure to e-cigarette aerosol is more harmful when the animals also drink alcohol.¹¹ In the males, reward-related learning (enhanced sign-tracking) was affected by e-cigarette aerosol exposure during adolescence, and this effect was not affected by alcohol. Interestingly, e-cigarette aerosol exposure did not affect reward-related learning in females. This work suggests that alcohol does not exacerbate the effects of nicotine on reward learning. Many people who use methamphetamine also smoke cigarettes. Cardenas et al. investigated whether adolescent and adult nicotine exposure affects the self-administration of methamphetamine.¹² Pretreatment with nicotine enhanced methamphetamine self-administration in the adolescent male but not adolescent female rats. In contrast, adult nicotine treatment increased methamphetamine self-administration in the females but not the males. This suggests that adolescent smoking or vaping can affect methamphetamine intake and may thereby increase the risk of methamphetamine abuse, but these effects are age- and sex-dependent.

This issue also includes several clinical articles about the co-use of nicotine and other drugs of abuse. Twitter is a social networking site that allows people to post brief messages and can provide valuable insight into the relationship between the co-use of alcohol and tobacco. Previous work has described that the co-use of nicotine and alcohol is extremely common. It has been estimated that 30% of smokers are alcoholics, and 80% of alcoholics smoke.¹³ In this issue, Russell et al. show that the great majority of the tweets they analyzed were in favor of the co-use of alcohol and tobacco, that alcohol causes tobacco craving, and that alcohol contributes to a higher level of smoking and relapse.¹⁴ Another article reported the effects of alcohol and cannabis on both increased positive affect and decreased negative affect (overall mood boost) associated with smoking; smoking provided a mood boost, but the magnitude of the mood boost was not affected by alcohol or cannabis.¹⁵

Overall, these studies indicate that people are very interested in co-using nicotine and other drugs of abuse. The co-use of nicotine with other drugs might lead to higher nicotine intake level and contributes to relapse. The animal studies also underscore that there is a complex interaction between nicotine and other drugs of abuse, and these effects depend on age, dose, and sex.

Supplementary Material

A Contributorship Form detailing each author’s specific involvement with this content, as well as any supplementary data, are available online at https://academic.oup.com/ntr.

Funding

AWB was supported by a National Institute on Drug Abuse (NIDA)/National Institutes of Health (NIH) grant DA046411.

Declaration of Interests

The author has no conflict of interest to disclose.