E-cigarette smoking and depressive disorders: A systematic review of clinical studies

Abstract

Background:Increased use of Electronic cigarette (e-cigarette) denotes an important area of urban health which, particularly among adolescents and young adults, prompting concerns about its impact on mental health, including the development and exacerbation of depression. The objective was to qualitatively synthesize results from clinical observational studies on the association between e-cigarette use and depression, elucidate prevailing themes.

Methods:A systematic search of PubMed, Scopus, and EMBASE databases was performed from inception to January 2025. The following search terms and MeSH phrases were utilized, “e-cigarette,” “vaping,”“depression,” and clinical study type was selected . We included all observational clinical studies of any type which reported association of e-cigarette use and depressive disorders. Moreover, two reviewers separately carried out study selection, data extraction, as well as quality assessment using the Newcastle–Ottawa Scale and adhered to PRISMA guidelines.

Results:In adult or adolescent subpopulations, studies showed e-cigarette users may experience higher clinical depressive presentations and clinical depression. It is suggested that even when adjusting for socioeconomic factors, effect of e-cigarette smoking could be persisted. Qualitative themes from adolescent surveys revealed that some youths vape to self-medicate negative mood states but experience raised irritability and low mood during nicotine withdrawal. Internalisation of mental problems sometimes were found to occur before starting e-cigarette indicating a self-medication motivation in individuals with raised depressive symptoms. Risk of bias assessment suggested frequent reliance on self-reported depression measures, lack of control for multiple substance use, cross-sectional nature of study designs, and variability in depression assessment scales.

Conclusions:Our study suggests indicates a rather consistent co-occurrence of electronic cigarette usage and depression among studies, with concepts of self-medication and mood dysregulation emerging among adolescents. However, the directionality and causality of this relationship remain unclear due to methodological heterogeneity warranting rigorous, standardized large-scale prospective to look into temporal and associations.