Nicotine Gateway Effects on Adolescent Substance Use.

Shahrdad Lotfipour,Michelle Ren

doi:10.5811/westjem.2019.7.41661

Shahrdad Lotfipour, Michelle Ren

Open Access

https://doi.org/10.5811/westjem.2019.7.41661

Copy DOI

Abstract

Given the rise in teenage use of electronic nicotine delivery systems (“vaping”) in congruence with the increasing numbers of drug-related emergencies, it is critical to expand the knowledge of the physical and behavioral risks associated with developmental nicotine exposure. A further understanding of the molecular and neurochemical underpinnings of nicotine’s gateway effects allows emergency clinicians to advise patients and families and adjust treatment accordingly, which may minimize the use of tobacco, nicotine, and future substances. Currently, the growing use of tobacco products and electronic cigarettes among teenagers represents a major public health concern. Adolescent exposure to tobacco or nicotine can lead to subsequent abuse of nicotine and other substances, which is known as the gateway hypothesis. Adolescence is a developmentally sensitive time period when risk-taking behaviors, such as sensation seeking and drug experimentation, often begin. These hallmark behaviors of adolescence are largely due to maturational changes in the brain. The developing brain is particularly vulnerable to the harmful effects of drugs of abuse, including tobacco and nicotine products, which activate nicotinic acetylcholine receptors (nAChRs). Disruption of nAChR development with early nicotine use may influence the function and pharmacology of the receptor subunits and alter the release of reward-related neurotransmitters, including acetylcholine, dopamine, GABA, serotonin, and glutamate. In this review, we emphasize that the effects of nicotine are highly dependent on timing of exposure, with a dynamic interaction of nAChRs with dopaminergic, endocannabinoid, and opioidergic systems to enhance general drug reward and reinforcement. We analyzed available literature regarding adolescent substance use and nicotine’s impact on the developing brain and behavior using the electronic databases of PubMed and Google Scholar for articles published in English between January 1968 and November 2018. We present a large collection of clinical and preclinical evidence that adolescent nicotine exposure influences long-term molecular, biochemical, and functional changes in the brain that encourage subsequent drug abuse.

Highlights

The growing use of tobacco and electronic nicotine delivery systems (“vaping”) among teenagers represents a major public health concern
We argue that the effects of nicotine are highly dependent on timing of exposure, and that nicotinic acetylcholine receptors (nAChRs) interact with other drug receptor systems to directly mediate reward and reinforcement
The development, projections, and functions of this pathway are strongly influenced by acetylcholine, glutamate, serotonin, and GABA.[67,68,69,70,71]

Summary

Introduction

The growing use of tobacco and electronic nicotine delivery systems (“vaping”) among teenagers represents a major public health concern. Previous reports highlight that the rates of cigarette smoking are decreasing in the United States (U.S.), from 20.9 percent in 2005 to 15.5 percent in 2016, current trends in teen use of electronic nicotine delivery systems (e.g., e-cigarettes, vaporizers, hookah pens) are rapidly increasing.[24,25,26] In particular, the rate of current e-cigarette use in high school students jumped from 1.5 percent in 2011 Smoking is the leading cause of preventable death worldwide, but epidemiological, clinical, and preclinical data have shown that adolescent exposure to tobacco or nicotine can lead to subsequent abuse of nicotine and other substances.[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19] This phenomenon is known as the gateway hypothesis.[10,20,21] adolescents are more likely to first experiment with combustible cigarettes and/or e-cigarettes than they are marijuana.[22,23] Sequence patterns of drug initiation were examined in a recent study (2015), which reported that 38.8 percent of adolescents initiate nicotine before alcohol and/ or marijuana, while 21.3 percent use alcohol prior to nicotine and/or marijuana, and 8.6 percent use marijuana before nicotine and/or alcohol.[23]

Methods

Results

Conclusion