Caffeine is has a well-known stimulant effect. It has a chemical structure that resembles an endogenous chemical called adenosine. Your body uses adenosine to signal that you are tired. The caffeine fits into your brain’s adenosine receptors, effectively blocking them. So you have a sense of alertness and energy for a few hours.

Some natural stimulants like dopamine work better when the adenosine receptors are blocked, and also the adrenal glands secrete adrenaline, another stimulant.

If you take caffeine regularly, your body will actually grow more adenosine receptors, and decreases the number of receptors for norepinephrine, another stimulant. For these reasons, caffeine users will tend to develop a Tolerance for caffeine, meaning that it has less effect, and there are symptoms of Withdrawal (like tiredness, depression, headaches) if you stop using it. These symptoms can last a week or so.

Source in Smithsonian.

Caffeine and Nicotine

In the early days of AA, it was nearly impossible to find an AA meeting that did not have lots of coffee available, and just about everybody smoked. Some family members worried that maybe the alcoholics had just substituted caffeine and tobacco for the alcohol.

But even though both drugs, caffeine and nicotine, show physical tolerance and withdrawal, somehow they seem different. Most people do not experience severe consequences of their caffeine use. Unless you have a severe cardiac problem or some other medical condition that makes caffeine life threatening, there just don’t seem to be the consequences we see in full-fledged addiction. Nicotine, on the other hand, has severe health consequences, so even though there does not seem to be the kind of mood-altering effect we see with alcohol and many other drugs, there is no doubt about the negative consequences of tobacco.


Caffeine shows us another dimension to addiction. Even with evidence of tolerance and withdrawal, we will have difficulty calling it an addiction unless there are some pretty strong consequences of using it and not being able to stop. There is a group called Caffeine Addicts Anonymous, but it seems to be only one group, somewhere in Delaware.

Caffeine, see also: Addiction, Arousal, Nicotine, Tolerance, Withdrawal.

Created 3 Oct 2015

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Addictionary 2 by Jan & Judy Wilson

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