Why do coffee drinkers feel more clear headed after consuming caffeine? Why do some get a headache without it? Does caffeine cause any permanent brain changes and can the brain go back to ‘normal’ after years of caffeine use?
In: Biology
This is all based on my very basic understanding of brain chemistry, so be patient and don’t @ me, scientists.
Your brain produces a chemical called adenosine, which makes you sleepy. The longer you’re awake, the more work adenosine puts in. You have adenosine receptors, which take in adenosine and make it work.
Caffeine is an “adenosine receptor antagonist.” That means that it makes your adenosine receptors stop working. This means that your brain will not take in the adenosine it produces, so when you drink coffee you stop feeling sleepy and stay awake longer. This means you’re more alert, and your motor skills are a bit tighter.
I’m not clear on even the basic science of this aspect, but caffeine also has the indirect effect of increasing the levels of dopamine (the happy chemical) in your system. This means you generally are in a better mood when you take caffeine. This is important when you think about what happens when you stop taking caffeine.
Again, I’m unclear on the science of withdrawal but after your body becomes accustomed to a certain level of chemicals, changing those levels leads to withdrawal symptoms like headaches, nausea, etc. This is “physical addiction:” your body’s negative reaction to a chemical, or the lack of a chemical.
Because caffeine is only mildly physically addictive, the nature of the addiction is physical only to a small extent. The effect is real, but the reaction to it is more of a psychological addiction. You like the way you feel when you have all this dopamine in your system, and you know that when you stop, you’re going to feel cranky, tired, sluggish and uncoordinated and have a headache. So, you drink more caffeine to avoid feeling that way. This is a roundabout way of saying that your body’s reaction to caffeine withdrawal is minor and temporary, but the psychological need to avoid those symptoms leads to continuing use.
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