Environmental smoking and smoking onset in adolescence: the role of dopamine-related genes. Findings from two longitudinal studies

Candidate gene-environment interactions in substance abuse: A systematic review

BACKGROUND

The abuse of psychogenic drugs can lead to multiple health-related problems. Genetic and environmental vulnerabilities are factors in the emergence of substance use disorders. Empirical evidence regarding the gene-environment interaction in substance use is mixed. Summaries of the latest findings from a candidate gene approach will be useful for revealing the significance of particular gene contributions. Thus, we aim to identify different gene-environment interactions in patterns of substance use and investigate whether any effects trend notably across different genders and races.

METHODS

We reviewed published studies, until March 1, 2022, on substance use for candidate gene-environment interaction. Basic demographics of the included studies, target genes, environmental factors, main findings, patterns of gene-environment interaction, and other relevant information were collected and summarized.

RESULTS

Among a total of 44 studies, 38 demonstrated at least one significant interaction effect. About 61.5% of studies on the 5-HTTLPR gene, 100% on the MAOA gene, 42.9% on the DRD2 gene, 50% on the DRD4 gene, 50% on the DAT gene, 80% on the CRHR1 gene, 100% on the OPRM1 gene, 100% on the GABRA1 gene, and 50% on the CHRNA gene had a significant gene-environment interaction effect. The diathesis-stress model represents a dominant interaction pattern (89.5%) in the studies with a significant interaction effect; the remaining significant effect on substance use is found in the differential susceptibility model. The social push and swing model were not reported in the included studies.

CONCLUSION

The gene-environment interaction research on substance use behavior is methodologically multidimensional, which causes difficulty in conducting pooled analysis, or stated differently-making it hard to identify single sources of significant influence over maladaptive patterns of drug taking. In decreasing the heterogeneity and facilitating future pooled analysis, researchers must (1) replicate the existing studies with consistent study designs and measures, (2) conduct power calculations to report gene-environment correlations, (3) control for covariates, and (4) generate theory-based hypotheses with factorial based experiments when designing future studies.

Improving knowledge and attitudes about prevention and cessation of smoking using comics: study on youth with smoker's social environment

Introduction

it is needed the innovative interventions to promote smoking cessation behavior. This research analyzed the influence of comic as the communication media to the knowledge and attitude of the respondent in the various determinant of smoking behavior.

Methods

this research measured the knowledge and attitude of the respondent after they have been given comic as the educational media. It also explored the information about smoking status and social context of the smokers, such as smoker parents, friends, and teachers. The population was the students. The sample size was 1000 students of junior high school. The research aimed to find out the difference of knowledge and attitude based on the smoking status, social context, and training experience.

Results

the mean score of knowledge between the respondents who had trained was higher than respondents who had no trained was significantly different (p<0.05). There was also significantly different of the mean score of knowledge and attitude (p<0.05) between the respondents whose family were smoker and non-smoker. The mean score of knowledge and attitude between the smoker and non-smoker respondents was also significantly different (p<0.05).

Conclusion

the comic is more effective as an educational media for non-smoker adolescents, adolescents who have not smoker family, and health educated adolescent.

Genetic influences impacting nicotine use and abuse during adolescence: Insights from human and rodent studies

Nicotine use continues to be a major public health concern, with an alarming recent rise in electronic cigarette consumption. Heritability estimates of nicotine use and abuse range from 40% to 80%, providing strong evidence that genetic factors impact nicotine addiction-relevant phenotypes. Although nicotine use during adolescence is a key factor in the development of addiction, it remains unclear how genetic factors impact adolescent nicotine use and abuse. This review will discuss studies investigating genetic factors impacting nicotine use during adolescence. Evidence from both rodent and human studies will be summarized and integrated when possible. Human adolescent studies have largely included candidate gene studies for genes identified in adult populations, such as genes involved in nicotine metabolism, nicotinic acetylcholine receptor signaling, dopaminergic signaling, and other neurotransmitter signaling systems. Alternatively, rodent studies have largely taken a discovery-based approach identifying strain differences in adolescent nicotine addiction-relevant behaviors. Here, we aim to answer the following three questions by integrating human and rodent findings: (1) Are there genetic variants that uniquely impact nicotine use during adolescence? (2) Are there genetic variants that impact both adolescent and adult nicotine use? and (3) Do genetic factors in adolescence significantly impact long-term consequences of adolescent nicotine use? Determining answers for these three questions will be critical for the development of preventative measures and treatments for adolescent nicotine use and addiction.

Gene-by-peer-environment interaction effects on cigarette, alcohol, and marijuana use among US high school students of European Ancestry

Research has shown that adolescents' substance use behavior is determined not only by individual characteristics but also by peer environments, and an emerging literature in social genomics has also found that individual genotypes moderate peer effects on egos' substance use. However, the previous literature on genetic by peer environment (GxPE) interaction effects is limited by the use of genetic measures with limited power and a lack of focus on causality. Based on a sample of about 4000 adolescents of European Ancestry from the National Longitudinal Study of Adolescent to Adult Health, this study utilizes polygenic scores to examine GxPE interactions between ego's genetics and peers' cigarette, alcohol, and marijuana use. The results show peers' cigarette and marijuana use positively affect ego's substance use, and peer effects are stronger when the ego is genetically predisposed to substance use. However, genetic propensities toward risk tolerance are found to weaken the peer effects on the ego's marijuana use. Overall, our findings provide new evidence for the existence of GxPE effects on adolescent substance use and reveal the multidimensional nature of GxPE effects.

Investigating the association between smoking, environmental tobacco smoke exposure and reward-related brain activity in adolescent experimental smokers

Reduced anticipatory reward‐related activity, especially in the ventral striatum (VS), may underly adolescent vulnerability to develop nicotine dependence. It remains unclear whether nicotine uptake caused by environmental tobacco smoke (ETS) exposure, known to be associated with future smoking, might prompt similar changes in the brain's reward system, rendering adolescents vulnerable for development of nicotine dependence. To address this question, we tested whether current ETS exposure and monthly smoking are associated with VS hypoactivity for non‐drug rewards in experimental smoking adolescents. One‐hundred adolescents performed a monetary incentive delay task while brain activity was measured using fMRI. To test the hypothesized relationship, we used a variety of approaches: (1) a whole‐brain voxel‐wise approach, (2) an region‐of‐interest approach in the VS using frequentist and Bayesian statistics and (3) a small volume voxel‐wise approach across the complete striatum. The results converged in revealing no significant relationships between monthly smoking, ETS exposure and reward‐related brain activation across the brain or in the (ventral) striatum specifically. However, Bayesian statistics showed only anecdotal evidence for the null hypothesis in the VS, providing limited insight into the (non‐)existence of the hypothesized relationship. Based on these results, we speculate that blunted VS reward‐related activity might only occur after relatively high levels of exposure or might be associated with more long term effects of smoking. Future studies would benefit from even larger sample sizes to reliably distinguish between the null and alternative models, as well as more objective measures of (environmental) smoking via using devices such as silicone wristbands.

The influence of peer behavior as a function of social and cultural closeness: A meta-analysis of normative influence on adolescent smoking initiation and continuation

Although the influence of peers on adolescent smoking should vary depending on social dynamics, there is a lack of understanding of which elements are most crucial and how this dynamic unfolds for smoking initiation and continuation across areas of the world. The present meta-analysis included 75 studies yielding 237 effect sizes that examined associations between peers' smoking and adolescents' smoking initiation and continuation with longitudinal designs across 16 countries. Mixed-effects models with robust variance estimates were used to calculate weighted-mean Odds ratios. This work showed that having peers who smoke is associated with about twice the odds of adolescents beginning (OR ¯ = 1.96, 95% confidence interval [CI] [1.76, 2.19]) and continuing to smoke (OR ¯ = 1.78, 95% CI [1.55, 2.05]). Moderator analyses revealed that (a) smoking initiation was more positively correlated with peers' smoking when the interpersonal closeness between adolescents and their peers was higher (vs. lower); and (b) both smoking initiation and continuation were more positively correlated with peers' smoking when samples were from collectivistic (vs. individualistic) cultures. Thus, both individual as well as population level dynamics play a critical role in the strength of peer influence. Accounting for cultural variables may be especially important given effects on both initiation and continuation. Implications for theory, research, and antismoking intervention strategies are discussed. (PsycINFO Database Record

Genotype × Environment Interaction in Smoking Behaviors: A Systematic Review

INTRODUCTION

There has been rapid growth in research exploring gene-environment interaction (G×E) contributing to smoking behaviors. Yet, no systematic review exists to date.

METHODS

This article aims to review evidence on the contribution of G×E to the risk of smoking. Through a search of electronic databases (ie, Google Scholar, PubMed, ScienceDirect, and Elsevier) up until May 2014, 16 studies of G×E focused on smoking behaviors were identified. These studies were compared in terms of: research design and sample studied, measure of smoking behavior and environments used, genes explored, and G×E in relation to these factors.

RESULTS

Thirteen of 16 studies (81.2%) found at least one significant G×E association. Wide variation in analytic methods was found across studies, especially with respect to the phenotypes of interest, environmental measures used, and tests conducted to estimate G×E. Heterogeneity across studies made it difficult to compare findings and evaluate the strength of evidence for G×E.

CONCLUSIONS

G×E research on smoking contains studies that are methodologically different, making it difficult to assess the current state of the evidence. To decrease heterogeneity, we offer recommendations related to: (1) choice of measurement for environmental variables, (2) testing and reporting of main and interaction effects, (3) treatment of covariates, (4) reporting gene-environment correlation, and (5) conducting sensitivity analyses and checking for scaling artifacts. Continued study is needed to identify mechanisms by which genes and environmental factors combine to influence smoking behaviors.

IMPLICATIONS

No comprehensive review of G×E studies of smoking behavior has previously been published. The present article seeks to fill this gap by providing a comprehensive review of: how G×E has been defined, how twin and molecular genetic methodologies have been used to test for G×E, and which genes and environmental factors are associated with smoking behaviors. Variations in methodological approaches make it difficult to interpret and summarize findings, so recommendations for future research are provided as a means to more easily compare and replicate findings across studies.

Narrative review of genes, environment, and cigarettes

Tobacco use remains the leading cause of preventable death in the US, emphasizing the need to understand which genes and environments are involved in the establishment of cigarette use behaviors. However, to date, no comprehensive review of the influence of genes, the environment, and their interaction on cigarette use exists. This narrative review provides a description of gene variants and environmental factors associated with cigarette use, as well as an overview of studies investigating gene-environment interaction (GxE) in cigarette use. GxE studies of cigarette use have been useful in demonstrating that the influence of genes changes as a function of both the phenotype being measured and the environment. However, it is difficult to determine how the effect of genes contributing to different phenotypes of cigarette use changes as a function of the environment. This suggests the need for more studies of GxE, to parse out the effects of genes and the environment across the development of cigarette use phenotypes, which may help to inform potential prevention and intervention efforts aimed at reducing the prevalence of cigarette use. Key Messages No comprehensive reviews of the influence of genes, the environment, and their interaction on cigarette use exist currently. The influence of genes may change as a function of the environment and the phenotype being measured. It is difficult to determine how the effect of genes contributing to different phenotypes of cigarette use changes according to environmental context, suggesting the need for more studies of gene-environment interaction related to cigarette use to parse out effects.

Parental smoke exposure and the development of nicotine craving in adolescent novice smokers: the roles of DRD2, DRD4, and OPRM1 genotypes

BACKGROUND

Among adolescent novice smokers, craving is often the first, and is the most reported, symptom of nicotine dependence. Until now, little has been known about the development of craving symptoms in novice smokers. The aim of this study was to identify specific genetic (i.e., DRD2 Taq1A, DRD4 48 bp VNTR, and OPRM1 A118G polymorphisms) and environmental mechanisms that underlie the emergence of both cue-induced and cognitive craving among adolescent novice smokers.

METHOD

A five-wave longitudinal, genetically-informed survey study was conducted with intervals of four months. The sample included 376 early adolescent smokers (12-13 years of age at baseline). Self-report questionnaires were completed regarding smoking behavior, observed parental smoking behavior, and both cue-induced and cognitive craving.

RESULTS

Data were analyzed with a latent growth curve approach. For both cue-induced and cognitive craving, significant interaction effects were found for DRD2 Taq1A with parental smoke exposure. A1-allele carriers did not seem to be influenced by the environment with regard to craving development. Adolescents who are homozygous for the A2-allele and who are more exposed to parental smoking experience the highest levels of both types of craving over time. No significant interaction effects were found between parental smoke exposure and DRD4 48 bp VNTR or OPRM1 A118G.

CONCLUSIONS

Previous studies identified DRD2 Taq1A A1-allele carriers as vulnerable to developing nicotine dependence. However, this study showed that parental smoking increased the chances of developing dependence more rapidly for early adolescents who are considered to be less sensitive to the rewarding effects of nicotine according to their DRD2 Taq1A genotype. It is thus especially important that these young people not be exposed to smoking in their social environment.

Effects of Interaction Between Dopamine D2 Receptor and Monoamine Oxidase A Genes on Smoking Status in Young Men

Although the effect of gene-gene interaction on nicotine-dopamine metabolism for smoking behavior has been reported, polymorphisms of dopamine D2 receptor (DRD2) and monoamine oxidase A (MAOA) have not been simultaneously examined among smokers. In this study, 481 young Taiwanese men completed a self-report questionnaire on smoking status, and data were obtained on polymorphisms of DRD2 rs1800497, DRD2 rs1079597, MAOA rs309850, and MAOA rs1137070, urinary nicotine, and urinary cotinine. In a comparison of 261 current smokers and 220 never smokers, odds ratios (ORs) for the development of smoking in all genotypes were not statistically significant. Among smokers with DRD2 rs1079597 GG//MAOA rs309850 3-repeat, the OR of heavier smoking was 2.67 times higher (95% confidence interval [CI]: [1.08, 6.59], p = .031) and the score on the Fagerstrom test for nicotine dependence was higher (4.26 vs. 2.83) than in those with DRD2 rs1079597 AA//MAOA rs309850 3-repeat. Adjusted urinary cotinine concentration was significantly different between those two groups (median value: 95.83 ng/μl vs. 133.24 ng/μl, respectively, p = .045). These findings suggest that the interaction of DRD2 rs1079597 and MAOA rs309850 3-repeat affects smoking intensity in young Taiwanese men.

Genetic variants and early cigarette smoking and nicotine dependence phenotypes in adolescents

Background

While the heritability of cigarette smoking and nicotine dependence (ND) is well-documented, the contribution of specific genetic variants to specific phenotypes has not been closely examined. The objectives of this study were to test the associations between 321 tagging single-nucleotide polymorphisms (SNPs) that capture common genetic variation in 24 genes, and early smoking and ND phenotypes in novice adolescent smokers, and to assess if genetic predictors differ across these phenotypes.

Methods

In a prospective study of 1294 adolescents aged 12–13 years recruited from ten Montreal-area secondary schools, 544 participants who had smoked at least once during the 7–8 year follow-up provided DNA. 321 single-nucleotide polymorphisms (SNPs) in 24 candidate genes were tested for an association with number of cigarettes smoked in the past 3 months, and with five ND phenotypes (a modified version of the Fagerstrom Tolerance Questionnaire, the ICD-10 and three clusters of ND symptoms representing withdrawal symptoms, use of nicotine for self-medication, and a general ND/craving symptom indicator).

Results

The pattern of SNP-gene associations differed across phenotypes. Sixteen SNPs in seven genes (ANKK1, CHRNA7, DDC, DRD2, COMT, OPRM1, SLC6A3 (also known as DAT1)) were associated with at least one phenotype with a p-value <0.01 using linear mixed models. After permutation and FDR adjustment, none of the associations remained statistically significant, although the p-values for the association between rs557748 in OPRM1 and the ND/craving and self-medication phenotypes were both 0.076.

Conclusions

Because the genetic predictors differ, specific cigarette smoking and ND phenotypes should be distinguished in genetic studies in adolescents. Fifteen of the 16 top-ranked SNPs identified in this study were from loci involved in dopaminergic pathways (ANKK1/DRD2, DDC, COMT, OPRM1, and SLC6A3).

Impact

Dopaminergic pathways may be salient during early smoking and the development of ND.