E-Cigarette Use, Systemic Inflammation, and Depression

Abstract

Background: E-cigarette use (vaping) is an emerging public health problem. Depression has been found to be associated with e-cigarette use, and vaping and depression are each associated with elevated systemic inflammation. To date, the role of inflammation in the relationship between vaping and depression has not been explored. Objective: To assess the independent associations between e-cigarette use, depression, and inflammation, and to investigate whether the likelihood of depression among current e-cigarette users is associated with systemic inflammation. Methods: Nationally representative NHANES data from 2015–2018 were used (n = 4961). Systemic inflammation was defined as serum C-reactive protein (CRP) ≥ 8.0 mg/L. Depressed individuals were characterized by a score ≥ 10 on the Patient Health Questionnaire-9 (PHQ-9). Current e-cigarette users were defined as individuals who vaped at least once in the past 30 days and these individuals were stratified by use: exclusive users (reported smoking less than 100 combustible cigarettes in their lifetime), dual users (reported current use of electronic and combustible cigarettes), and e-cigarette users who were previous smokers. Bivariate analyses were used to assess independent associations between vaping, depression, and inflammation; and weighted logistic regression analyses adjusting for BMI, sex, and economic status were used to determine the odds ratios (ORs) for depression by e-cigarette category stratified by differential CRP levels. Results: Depression occurred in 16.7% of all e-cigarette users vs. 5.0% of those who never used e-cigarettes (p < 0.001). In adjusted analyses, the following elevated ORs were found: all current e-cigarette users with CRP <8 = 3.37 (95% CI: 2.06, 5.51) vs. CRP ≥8 = 6.70 (2.48, 18.11); exclusive e-cigarette users with CRP <8 = 1.91 (0.78, 4.69) vs. those with CRP ≥8 = 5.09 (1.44, 18.02); and dual users with CRP <8 = 4.31 (2.35, 7.89) vs. those with CRP ≥8 = 7.37 (1.85, 29.41). These ORs indicate that depression is associated with each category of e-cigarette use; however, we found this association did not vary by systemic inflammation level (interaction p-values > 0.05). Conclusion: While a pattern of greater ORs for depression among e-cigarette users with elevated CRP provides provocative findings that might suggest a potential role of inflammation in the association between vaping and depression, we failed to find evidence that inflammation clearly moderates this association. While it is possible that depression among e-cigarette users may be influenced by systemic inflammation, a reproduction of the current study is necessary among a larger cohort to elucidate the effect of inflammation on depression among e-cigarette users.

Association between e-cigarette use behaviors and perceived harmfulness of e-cigarettes and anxiety/depression symptoms among Black/African American Adults

“…Similar to the literature on the general population ( Farrell et al, 2021 , Obisesan et al, 2019 , Park et al, 2017 , Saeed et al, 2020 , Sung, 2021 ), we found significant associations between e-cigarette use and anxiety/depression symptoms among Black/African American adults. While anxiety/depression symptoms were not associated with former e-cigarette use in this population, they were associated with current daily or someday e-cigarette use.…”

“…Studies revealed that individuals who perceived e-cigarettes as less harmful than cigarettes were more likely to be ever or current users of e-cigarettes ( Brose et al, 2015 , Cooper et al, 2016 , Huang et al, 2019 , Malt et al, 2020 , Rass et al, 2015 , Wackowski and Delnevo, 2016 ). Those with anxiety/depression symptoms were more likely to use e-cigarettes than their counterparts without anxiety/depression ( Farrell et al, 2021 , Obisesan et al, 2019 , Park et al, 2017 , Saeed et al, 2020 , Sung, 2021 ). Individuals with mental health disorder symptoms perceived e-cigarette use as less harmful, but they were more likely to use e-cigarettes than those who did not use e-cigarettes ( Baltz and Lach, 2019 , Hefner et al, 2016 ).…”

Beyond the label: current evidence and future directions for the interrelationship between electronic cigarettes and mental health

“…Over 20 million adults in the United States suffer from depression (30), and multiple studies have demonstrated comorbidity between depression and electronic cigarette use (16,(31)(32)(33)(34)(35)(36)(37)(38)(39). This association is also dose-dependent, where greater amounts of nicotine consumed were associated with greater self-reported depressive symptoms (40).…”

Use of Electronic Cigarettes among Secondary School Students and their Association with Depressive Symptoms: Findings from a National Secondary School Survey in Thailand

“…As nicotine has psychoactive properties 21 , it is possible that adolescents with depressive symptoms use electronic cigarette as a method to intake nicotine, similar to the pattern in conventional cigarette use, or vice versa 22 . Previous studies and reviews 13,[22][23][24][25] have reported that depression was associated with electronic cigarette use. However, as depression occurs in a gradient rather than as a binary, the pattern of associations between levels of depression and electronic cigarette use has not been fully explored.…”