An increasing body of research indicates that smoking is harmful not only to physical health but also to mental health. While it was previously assumed that individuals with mental health problems were more likely to start smoking, more recent evidence suggests that smoking itself may play a causal role in the development of mental disorders.
Large-scale epidemiological studies show that smokers have a significantly higher risk of developing depression, panic attacks, and anxiety disorders compared to non-smokers, even when no mental health problems were present at baseline. Furthermore, individuals with anxiety disorders do not initiate smoking more frequently than others, suggesting that smoking may precede the onset of anxiety rather than result from it.
Proposed mechanisms include the effects of nicotine on the autonomic nervous system—such as increased heart rate, elevated blood pressure, and accelerated breathing—as well as alterations in the brain’s dopaminergic system. Carbon monoxide in tobacco smoke may trigger panic-like symptoms, while long-term smoking promotes inflammatory processes in the brain that are associated with mental disorders.
Research also indicates an association between smoking and an increased risk of psychosis and bipolar disorder. The observation that certain antidepressants facilitate smoking cessation further supports the existence of shared neurobiological pathways between nicotine dependence and depression.
Although questions remain regarding the role of additional factors, such as alcohol consumption, the available evidence suggests that smoking cessation benefits not only physical health but mental health as well.