Studies Establishing How Smoking Causes Depression
The Epidemiologic Catchment Area (ECA) survey revealed that about 70% of male habitual smokers and 80% of female habitual smokers had major depression. The study also established that 30% of smokers show some symptoms of depression.
The Henry Ford Health System study confirmed that daily smokers (a person who smokes daily for one or more months) are twice at more risk of developing major depression than occasional smokers.
Almudena Sánchez-Villegas, professor, University of Navarra, based his research on a 6 year study of 8,556 university graduates (average age of 42) over a 6 year period. During the study 190 smokers, who initially did have signs of depression, were diagnosed with the disease. Also, 65 participants who had been diagnosed with depression indicated they were taking antidepressants at some point during the study period. Overall, smokers have a 41% higher risk of suffering from depression according to the study.
Some neurobiologic evidences also confirm the fact that tobacco smoke plays a crucial role in causing depression.
Figures from the World Health Organisation (WHO) show that 30 percent of inhabitants in the western world smoke daily. Earlier studies have found that people with mental health problems are twice as likely to smoke as the rest of the population. Injuries to physical health after smoking are well documented. It is also known that smoking is linked to other psychological problems. Anxiety and depression are the most common complaints and are often both present in people who smoke.
Why Smoking Causes Depression?
Smoking causes depression because of the withdrawal from a physically and psychologically addictive substance, called nicotine.
Nicotine which acts as a receptor for the neurotransmitter, acetylcholine, indirectly stimulates the release of another neurotransmitter, dopamine, in the brain’s reward or motivation center. Eventually the brain becomes so much adapted to the presence of the drug that it no longer functions normally without it. After 20-30 minutes of smoking the last cigarette, nicotine withdrawal begins. This leads to anxiety, which is very closely related to depression.
Smoking as well as quitting smoking, both cause depression. Depression occurs when the smoker tries to abstain himself from smoking.
Smoking as Anti-Depressant
However, one of the new researches has suggested that there may be something in cigarette smoke that has antidepressant properties as well, which explains why cigarette smoking is much more common among depressed patients. A survey of 3,000 individuals in the St. Louis area confirmed that lifetime frequency of major depression was more common among smokers than nonsmokers (6.6 vs. 2.9 percent) This study also demonstrated that smokers who reported at least one episode of major depression were less likely to succeed in smoking cessation programs than smokers without depression (14 vs. 28 percent). These findings have been confirmed many times over.
When you smoke, nicotine is absorbed by the lungs, enters the bloodstream and makes its way towards the brain. There it binds to receptors for dopamine, the brain's reward chemical. This accounts for the feeling of well-being experienced when smoking and is the basis of most addictive substances' appeal. Among people with depression, dopamine levels are often unusually low, so this is counteracted by the spike. However, this short-lived effect is only part of smoking's appeal for the depressed.
Also, there are thousands of chemicals other than nicotine constituents in cigarette smoke, of which one, or several, may affect mood in much the same way as a group of antidepressant medications called monoamine oxidase inhibitors or (MAOIs). These MAOIs effectively increase levels of specific neurotransmitters involved in the regulation of mood. Smoking, therefore, may be a way for depressed individuals to self-medicate depressive symptoms. Consequently, healthcare professionals who offer smoking cessation programs should offer depression screening and be prepared to address underlying mood disorders as part of a comprehensive smoking cessation program.
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