The Association between Smoking and Depression

Kim, Tae Suk; Kim, Dai Jin

Abstract

Researchers now widely accept that smoking is the major cause of various physical illnesses, but the relationship between smoking and psychiatric disorders, especially depression, is less clear. Nicotine is the primary addictive substance in cigarettes; in addition to causing a physiological dependence by activating a dopamine reward circuity, it may have a significant relationship with neurotransmitter variation, inducing psychiatric symptoms. The prevalence of smoking is much higher among depressed patients, and because depression may play a part in the psychological dependence of smoking, there may be a significant association between smoking and depression. This article reviews recent studies on the complicated interactions between smoking and depression, focusing on clinical and neurobiological research. It presents a clinical investigation of smoking as a risk factor for the development of depression, depression as a risk factor for beginning to smoke, and the effects of depression on smoking cessation. It also provides further understanding of the association between smoking and depression within a neurochemical, pharmacological, and genetic framework.