Smoking tobacco has powerful effects on the central nervous system. Cigarettes act as a central nervous system stimulant, affecting the neurotransmitters serotonin, dopamine, norepinephrine, acetylcholine, GABA and others. The most significant ingredient in tobacco smoke is nicotine, the component that causes addiction. There are also over 600 documented cigarette additives in commercial tobacco, and 100 of these have been found to have pharmacological effects on the body, especially the central nervous system.
Smoking cigarettes affects the neurotransmitters associated with anxiety and the state of wellness. Smokers have significantly higher rates of clinical anxiety compared to non-smokers. This may be explained through tobacco's effect on GABA, the neurotransmitter most responsible for the state of wellness and a lack of anxiety. In the September 2007 issue of "BMC Neuroscience," Dr. Tamaki Hayase found that nicotine significantly increased anxiety related behaviors and symptoms, even 2 hours after the last exposure. In addition, in the June 2007 issue of the "Journal of Applied Biobehavioral Research," Dr. Janet Audrain and associates found that anxiety was significantly correlated to nicotine intake. The largest co-factors in smoking-related anxiety were level of addiction, when people smoked because they were having a bad day, smoked in order to wake up, and smokers who had low levels of self-esteem.
Smoking is also strongly related to depression. Nicotine and other tobacco additives have a direct negative impact on dopamine and serotonin, two neurotransmitters associated with depression and mental health. Some smokers may use cigarettes to feel better, while nicotine withdrawal may itself cause the depression in the first place. In the January 2008 issue of "Nicotine & Tobacco Research," Dr. Michael Lyons and associates found that major depression was significantly associated with current daily smoking as well as nicotine withdrawal. Some of the accompanying depressive symptoms were nervousness, restlessness and difficulty concentrating.
Smoking cigarettes can also have a serious negative impact on cognitive abilities, especially with long-term smokers. Nicotine directly affects the neurotransmitters associated with learning, memory and cognition. The hundreds of additives in cigarettes also have a negative effect of cognition. Long term smokers are at a particular risk for developing dementia as they get older. In the August 2007 issue of "Neuropsychology Review," Dr. Gary Swan and associates found that smoking was significantly associated with brain matter degeneration and cellular death, cognitive decline over repeated measures and dementia. In the report, they also found that mothers who smoke put their child at an increased risk for neuro-developmental deficits.