The different types of dependency
Some experts make a difference between physical, psychological and behavioral dependency. The idea being that physical dependence is due to the impact of the active substance on the brain (in the case of tobacco, this is nicotine). While psychological dependence and behavioral addiction would be related to other factors: smoking is more likely when you are in a particular state of mind, or in a particular situation. For some, the desire to smoke comes when they are in the presence of other smokers. For others, it's more likely to be when reading a book, using the computer, having a coffee or a drink.
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The classification by type of dependency is somewhat out of date. Today, many researchers believe that, despite its complexity we should not try to subdivide dependency, as there are no clear scientific rules for doing so. Be that as it may, we can review the types of dependence, bearing in mind that they are probably different ways of understanding the same reality.
Dr. Thomas Rathelot, of the division of addictology at Geneva University Hospitals (HUG) takes another look at the distinction between physical and psychological dependence:
Physical or pharmacological dependence can probably be explained by the increase, among smokers, of the number of "nicotinic receptors" on the surface of nerve cells. These receptors are called nicotinic because nicotine binds to them very strongly in laboratory conditions (and when you smoke!).
But under natural conditions, there is no nicotine in the human body: the nicotinic receptors are in fact designed to receive acetylcholine, which is one of the most common neurotransmitters in the human body, especially within the brain, but also in terms of muscle activation.
So taking nicotine is likely to have effects at conscious and unconscious levels in human beings. Among dependent subjects, studies show that the number of nicotinic receptors decreases slowly after smoking cessation. A normal level is only reached after 6 to 12 months at the earliest.
However, the acute effects associated with the physical addiction to nicotine (withdrawal symptoms), disappear 1-2 months after quitting smoking, according to the degree of dependence. For this reason it is important to follow the treatment (medical consultation, nicotine replacement therapy, bupropion) for at least 2 months.
Psychological dependence lasts longer than physical dependence, and is more difficult to define. People with this type of addiction need cigarettes to think, to relax or simply to feel good. Some smokers even think they are not able to live without tobacco, and that the product is an integral part of their adult lives. It takes 6 to 12 months or even more, to get rid of psychological dependence.
Although behavioral or environmental dependence is associated with psychological (and physical) dependence, it relates specifically to actions that are performed daily. This is far from trivial, since smokers carry their hands to their mouths several hundred times a day. It is to counteract the behavioral addiction that some people are advised, in the weeks after quitting smoking, to chew gum or candy, to keep their hands busy, or to walk with an object in their pocket to replace the cigarette pack.
The concept of oral fixation claims that the relationship with smoking is similar to the first feelings of pleasure and satisfaction provided by the maternal breast. The cigarette, always available, is carried to the mouth to calm all fears. Smokers who have an oral fixation problem are more likely than others to compensate for their weaning off of cigarettes by increasing their intake of food or alcohol.
In general, it is important to understand that the addiction to cigarettes is a combination of these factors. It is not because this or that person is sensitive to the psychological aspects that they do not react physically to the nicotine "rush" provided by each cigarette.
According to recent research analyzed by Italian researcher Christian Chiamulera, nicotine may act on the brain to link the different types of addiction, making smokers more aware of the tobacco-related triggers in their environment (smells, visual cues and atmosphere). It would also strengthen the unconscious link between these triggers and the act of smoking. Since nicotine stimulates the general circulation of nerve impulses in the brain, such an explanation is quite plausible.
The dependence of women on cigarette smoking undoubtedly has a stronger psychological component than that of men, which focuses more on the effect of nicotine rushes. Based on the work of American researcher Kenneth Perkins, women are more sensitive to the smell and taste of cigarettes too: if the smell or taste of their favorite brand is removed, they lose a lot more satisfaction than men do.
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Cue reactivity in nicotine and tobacco dependence: a "multiple-action" model of nicotine as a primary reinforcement and as an enhancer of the effects of smoking-associated stimuli. C Chiamulera. Brain Research Reviews, In Press (2004).
Sex differences in nicotine effects and self-administration: review of human and animal evidence. KA Perkins, E Donny, AR Caggiula. Nicotine & Tobacco Research 1(4), S. 301-315 (1999).
Nicotine Discrimination in Men and Women. KA Perkins. Pharmacology Biochemistry and Behavior 64(2), S. 295-299 (1999).