Association of depression and smoking cessation: outcomes of an 18-year retrospective cohort study

Abstract

Background Depression is frequently associated with unsuccessful smoking cessation. Objective In this study, we investigated the impact of depression history on smoking cessation success in a clinical setting. Methods This retrospective study included 726 patients who visited our smoking cessation clinic between January 1, 2001, and December 31, 2018. Kaplan–Meier analyses and Cox proportional hazards regression models were used to perform univariate and multivariate analyses of smoking cessation success factors. Results Among the 726 patients, 76 had a history of depression and demonstrated significantly lower 12-week quit rate compared to those without (33.6% vs. 69.6%, p < .001). Multivariate Cox analysis revealed a significant association between abstinence rate and history of depression (hazard ratio 2.251, 95% CI 1.505–3.315, p < .001), history of schizophrenia (hazard ratio 2.716, 95% CI 1.427–4.840, p = .003), and Fagerström Nicotine Dependence Test scores (hazard ratio 1.519, 95% CI 1.053–2.197, p = .025). Conclusions Our findings suggested that a history of depression is a significant prognostic factor for smoking cessation, underscoring the need for targeted interventions for patients with a history of depression. The findings of this study are subject to potential selection bias due to recruitment from a single hospital, which may limit the generalizability of our results. This study highlights the necessity for novel, specialized smoking cessation therapies to support patients with a history of depression in their cessation journey.