Depressed people are more likely to smoke than nondepressed people. Are depressed people more likely to smoke because of their anxiety and depression? Perhaps. A theory came to me two years ago that smoking may actually be a cause of depression, rather than an effect. I've found a few articles on the Internet suggesting that depression is a consequence of depression, but it seems very little research -- current or otherwise -- is being done on the subject. Call it a theory, call it a hypothesis, call it an observation; after all, I'm not a doctor, I only play one in real life.
Smokers have less concentration than nonsmokers; it's an idea which is well accepted if one does only a surface scan of information on the effects of smoking. Another fact is that withdrawal from a physically and psychologically addicting substance causes anxiety.
Nicotine withdrawal begins approximately 20-30 minutes from smoking your last cigarette. Anxiety is produced at even this "early stage" of withdrawal. When I was 19, I was prescribed antidepressant and antianxiety medication. The staff tested me with an MMPI (Minnesota Multiphasic Personality Inventory), and I was prescribed medication a week later. The fact that I had been smoking since I was 12 years old never came up with the doctor who prescribed the medication. I'm sure I told them I was a smoker; it just wasn't considered a factor. Based on that test, my treatment and several diagnoses since then, I am a "mentally ill person."
When I was 18, I was a nonsmoker for about one month. After I morphed back into a smoker, my grandmother made a comment, "You seemed a lot more pleasant when you weren't smoking."
Three years ago, I spent two months at a homeless shelter. I can remember two people there who were nonsmokers. Aside from those two individuals, most of the people at the shelter experienced depression, anxiety, mental illness, and substance abuse. I began to wonder then, "why is it so frequent that depressed people smoke?" Could smoking actually cause some depression? I sometimes meet people who smoke but who appear to function "normally," yet I still question if the chicken came before the egg, or if an omelet comes before breakfast or after I go to sleep (sometimes up to 8 hours later).
Smoking contracts a person's blood vessels, depletes vitamin's from one's body, and oxygen from blood and the brain. That being said, it's hard to believe that smoking is not looked at more closely by doctors and therapists who treat patients for depression.
There are other psychological reasons smoking may cause depression. It is despairing for me, a smoker, to realize I will need to buy more cigarettes when I run out. I feel a bit hopeless at times knowing I'm a slave to cigarettes. I sometimes feel fearful of a long car ride, and other situations where I'm not sure of when I'll get my next fix. I may not always be conscious of the anxiety and fear, but unconscious emotions are known to have an effect on occasion. Presently, I have a cheeseburger sitting in my mind, but I feel anxiety knowing that the money I would spend on a cheeseburger will instead go toward a pack of cigarettes.
I'm also keen to the widely-accepted belief that it's harder for people with depression or PTSD (Post Traumatic Stress Disorder) to quit smoking. I'm sure that there are many people with anxiety and depression problems who would still have problems if they were to quit smoking. I think that smoking is a major contributor, however, and one of the first things looked at during a course of treatment should be to quit smoking. I could see that many patients may not be open to such an idea; it's an addiction after all, arguably harder to quit than heroin. Hard evidence that depression is a significant factor contributing to one's depression would need to be produced to a patient. To my knowledge, that evidence doesn't exist yet.
It's important to remember the primary reason it feels good to smoke is that one is getting relief from withdrawal symptoms. Beyond the relief, there is no real reason sucking unknown chemicals and smoke into one's lungs should feel good.
I haven't referenced any web sites or medical journals, and none have been harmed in the writing of this article. The majority of research I found on the Internet had to do with a study in 2003. Here is a URL to an archived article on CNN's web site (originally from the Associated Press): Study suggests smoking can cause depression in teens.