Bidirectional associations between depressive symptoms and cigarette use during young adulthood: A survival analysis approach

Nicotine Tob Res. 2025 Nov 5:ntaf226. doi: 10.1093/ntr/ntaf226. Online ahead of print.

ABSTRACT

INTRODUCTION: Young adulthood is a pivotal period for mental health and tobacco use. Prior studies show a connection between smoking and depression, but the sequence of their effects remains unclear. This study explores the bidirectional associations between cigarette use and depressive symptoms in young adults aged 18-30.

METHODS: We analyzed data from 4,232 young adults (mean age=19.99, 64% female, 65% non-white) from 24 Texas colleges, across eight waves from 2014-2019. Survival analysis was conducted via multiple Cox regression, using age as the time variable and adjusting for wave, sex, and racial/ethnic identity. One model assessed if clinically significant depressive symptoms affected cigarette initiation, while another examined the influence of cigarette use on new onset of clinically significant depressive symptoms.

RESULTS: 7.6% of participants initiated cigarette use and 48.9% of participants reported new onset of depressive symptoms over the 4.5-year period. Depressive symptoms were associated with a 67% increase in the risk of cigarette initiation (HR=1.67, p<.001). Alternatively, cigarette use was associated with a 17% increase in the risk of new onset depressive symptoms (HR=1.17, p=.017).

DISCUSSION: Cigarette use and depressive symptoms have bi-directional associations among young adults. Interventions to prevent cigarette use should be tailored for young adults who experience depressive symptoms. Further, young adults who receive mental health treatment should be provided with smoking prevention resources.

IMPLICATIONS: This study provides evidence of bidirectional associations between cigarette use and depressive symptoms across young adulthood. Clinically significant depressive symptoms elevated the risk of cigarette initiation. Further, cigarette use elevated the risk of new-onset depressive symptoms. These findings have implications for prevention and intervention programs with young adults. Specifically, findings support the delivery of anti-smoking resources to young adults experiencing depression and the delivery of mental health resources to young adults who use cigarettes.

PMID:41206109 | DOI:10.1093/ntr/ntaf226