E-Cigarette Use and Depression Among American Indian Adults Who Smoke.

Objective: This study examined the association of e-cigarette use status and history of depression among American Indian (AI) adults who smoke.

Method: We conducted a secondary data analysis using survey data from 375 AI adult smokers collected in 2016 at a tribally operated healthcare facility in northeast Oklahoma. Multivariable logistic regression was used to estimate the association between e-cigarette use and self-reported history of depression while adjusting for potential confounders.

Results: In the adjusted analyses, compared to never users, current and former e-cigarette users had higher estimated odds of depression history (adj. OR 2.66; 95% CI 1.25-5.72 and adj. OR 2.38; 95% CI 1.36-4.26, respectively). Additional factors independently associated with a history of depression included having strong cravings to smoke (adj. OR 2.28; 95% CI 1.13-4.88) and having a history of chronic disease (adj. OR 2.09; 95% CI 1.20-3.70) after controlling for confounding variables.

Conclusions: E-cigarette use among AI adult smokers was independently associated with a history of depression. Whether e-cigarette use among people who smoke results from depression or whether depression results from the combined use of e-cigarettes and cigarettes requires future research using a prospective cohort design.