Smoking Linked to Higher Depression Risk, Study Reveals
Smokers and Former Smokers Face Higher Risk of Depression, Study Finds
People who smoke cigarettes or have smoked in the past face a higher risk of developing depression at some point in their lives compared to those who have never smoked, according to a new study led by researchers at the Central Institute of Mental Health (CIMH) in Mannheim, Germany.
Current smokers showed the highest risk of depressive symptoms, followed by former smokers, while non-smokers had the lowest risk.
Increased Depression Risk Linked to Smoking Habits
The study also identified a dose-response relationship: the more cigarettes smoked per day, the more severe the current depressive symptoms. Additionally, the earlier in life someone began smoking, the sooner they experienced their first depressive episode.
Conversely, those who started smoking later in life tended to develop depressive symptoms later as well. The data further revealed that quitting smoking—beyond its well-known physical health benefits—also improves mental well-being: the longer it had been since a person's last cigarette, the lower their risk of depression.
"Our findings underscore how crucial it is to prevent smoking initiation and promote cessation to enhance mental health," the researchers emphasized.
By Fabian Streit, Central Institute of Mental Health, Mannheim
The analysis drew on data from 173,890 adults aged 19 to 72, with an equal gender split (50% women, 50% men). Of these, 81,775 had never smoked, 58,004 were former smokers, and 34,111 were current smokers. The findings were based on Germany's largest population study, the NAKO Health Study, though the analysis focused solely on traditional tobacco cigarette use.
Published in the journal BMC Public Health, the study confirms a "strong link between smoking and depression," demonstrating a "clear dose-response relationship"—higher cigarette consumption correlated with more severe depressive symptoms, while a longer period since quitting was associated with fewer symptoms.
The most pronounced differences between smokers (current and former) and never-smokers were observed in the 40-to-59 age group. "This suggests that, alongside social factors,temporal effectsmay also play a role in the interplay between smoking and mental health," said Carolin Marie Callies, a doctoral researcher in health psychology at the University of Mannheim.
The results highlight that smoking is a significant and modifiable risk factor for both current and lifelong depression, while also indicating that quitting—or at least reducing cigarette consumption—could benefit mental health.
"Our findings emphasize the importance ofpreventing smoking uptakeandsupporting cessationto improve mental well-being," said study author Fabian Streit in a statement. "Particularly notable are the dose-dependent effects we observed: higher cigarette consumption was linked to more severe depressive symptoms, whereas a longer time since quitting corresponded with better mental health outcomes."
