Mental Health Gains Tied to Cessation, Not E-Cigarette Switching

Cessation, Switching, and the Psyche

The psychological benefits of smoking cessation are well-documented, with meta-analyses indicating that quitting is associated with significant reductions in depression, anxiety, and stress [1]. Clinical evidence suggests that patients who successfully achieve long-term abstinence experience more substantial symptom relief compared to those who struggle with relapse [2]. While electronic cigarettes have emerged as a common cessation aid, and some randomized trials suggest they may be more effective than traditional nicotine-replacement therapy for stopping combustible tobacco use [3], their long-term impact on mental health remains a subject of active investigation [4]. A large-scale observational study now clarifies how psychological trajectories differ between patients who achieve total nicotine abstinence and those who transition to electronic nicotine delivery systems.

Study Design and Population Prevalence

The researchers performed a cross-sectional analysis (an observational study that examines data from a population at a specific point in time) using a cohort of 218,921 Korean adults from the 2024 Korea Community Health Survey. To ensure the findings were representative of the general population, the study utilized survey-weighted multivariable logistic regression models. This statistical approach adjusts for the complex sampling methods of large-scale surveys and controls for multiple confounding variables to estimate the odds of specific clinical outcomes. The analysis focused on three primary mental health markers: depression, suicidal ideation, and poor sleep quality, categorized by smoking status and the number of years since combustible tobacco cessation.

Participants were stratified into six groups: never smokers, quitters (total nicotine abstinence), e-cigarette switchers (transitioned from combustible to electronic cigarettes), combustible cigarette-only users, e-cigarette-only users, and dual users. Within this massive dataset, the baseline prevalence of psychiatric concerns was significant. The researchers found that 3.5 percent of participants met the criteria for depression, while 1.2 percent reported suicidal ideation. Furthermore, 42.8 percent of the population reported poor sleep quality. These figures provide a clinical baseline for evaluating how different patterns of nicotine use correlate with long-term psychological stability or distress.

Mental Health Burden in Former and Current Smokers

The study identified a persistent mental health burden among individuals with any history of tobacco use, even after cessation. When compared to never smokers, individuals who had quit combustible cigarettes entirely still exhibited significantly higher odds of depression, suicidal ideation, and poor sleep quality. This suggests that the neurobiological or psychosocial effects of smoking may persist long after the last cigarette is extinguished. A similar and equally concerning pattern was observed in those who moved to electronic nicotine delivery systems: e-cigarette switchers also showed elevated odds across all three outcomes (depression, suicidal ideation, and poor sleep quality) compared to the never-smoker group.

These findings underscore a broader association between active nicotine use and psychological morbidity. The data confirmed that combustible cigarette smoking was associated with increased odds of adverse mental health outcomes, a risk that extended to modern alternatives. Specifically, the researchers determined that e-cigarette use was independently associated with increased odds of depression, suicidal ideation, and poor sleep quality. For the practicing clinician, these results indicate that neither traditional smoking nor switching to electronic cigarettes eliminates the heightened risk of psychiatric symptoms compared to the baseline of a never smoker.

Divergent Trajectories Over Time

The most clinically significant finding involves the temporal relationship between nicotine status and psychological recovery. For patients who achieve complete nicotine abstinence, the study found that the odds of adverse mental health outcomes demonstrated a clear decreasing trend with longer cessation duration. This suggests a gradual resolution of tobacco-related psychological distress, as sustained smoking cessation was associated with progressively lower odds of depression, suicidal ideation, and poor sleep quality as the years since quitting increased. This recovery trajectory provides a strong clinical incentive for patients to pursue total abstinence rather than harm-reduction alternatives.

In contrast, the psychological profile of those who transition to electronic cigarettes appears to stagnate or even deteriorate. The researchers found that e-cigarette switchers showed no clear duration-related trend for overall adverse mental health outcomes, meaning the passage of time did not provide the same psychological recovery seen in complete quitters. Most alarmingly, the study identified a specific risk regarding self-harm: among e-cigarette switchers, there was an increasing trend in the odds of suicidal ideation with longer cessation duration from combustible tobacco. While complete cessation facilitates a return toward baseline mental health, switching to e-cigarettes may be associated with a worsening risk of suicidal thoughts over time, a factor that should be closely monitored in patients using these devices as long-term substitutes.

References

1. Taylor G, McNeill A, Girling A, Farley A, Lindson N, Aveyard P. Change in mental health after smoking cessation: systematic review and meta-analysis. BMJ. 2014. doi:10.1136/bmj.g1151

2. Crabb AB, Allen J, Taylor G. What if I fail? Unsuccessful smoking cessation attempts and symptoms of depression and anxiety: a systematic review and meta-analysis.. BMJ open. 2025. doi:10.1136/bmjopen-2024-091419

3. Hájek P, Phillips‐Waller A, Przulj D, et al. A Randomized Trial of E-Cigarettes versus Nicotine-Replacement Therapy. New England Journal of Medicine. 2019. doi:10.1056/nejmoa1808779

4. Khoudigian S, Devji T, Lytvyn L, Campbell K, Hopkins R, O'Reilly D. The efficacy and short-term effects of electronic cigarettes as a method for smoking cessation: a systematic review and a meta-analysis.. International journal of public health. 2016. doi:10.1007/s00038-016-0786-z