Caffeine is so common -- the most commonly used drug in the world -- that most people don't realize it's a drug, and a psychoactive drug at that. Caffeine works on your whole body. But it has a very special mechanism in your brain, which can control the way the rest of your body responds. It worsens pre-existing anxiety symptoms. But it can also cause anxiety outright.
Your Dose
Perhaps you start your morning with a cup of coffee, which contains about 100 mg of caffeine. The coffee sloshes its way through your digestive tract, where the caffeine gets absorbed into your bloodstream. Because caffeine is so easily absorbed, you may begin feeling the effects within 15 minutes of your first sip. Once the caffeine is in your bloodstream, it circulates throughout your body and affects multiple bodily functions.
The Response
When the circulating caffeine reaches your brain, it binds to adenosine receptors, leaving no room for the actual adenosine to function. Adenosine is a neurotransmitter that acts like a natural tranquilizer, so when a strange molecule -- the caffeine -- blocks its plug-in point, the nerve cells are deprived of the calming effect. The nerve cells panic and signal for the adenosine, which tricks the pituitary gland into thinking that you're in danger. The pituitary gland communicates with the adrenal glands, which respond by releasing adrenaline to help you escape danger. The adrenaline tells your body to get ready for massive activity by altering your blood sugar to make fuel more available, dilating your airways to allow you to take in more oxygen and increasing your heart rate to allow you to run or fight as necessary.
The Reality
Nevertheless, you're not in danger. You might be sitting quietly at your desk, but your body is panicking, on high alert. You have extra strength, extra aerobic capacity and your emergency reserves of fuel circulating in your blood, but your body isn't using them. That's why you may begin to get jittery and anxious, because your body thinks there's an emergency, and all of this extra energy has nowhere to go. Caffeine affects your body the same way stress does. When you add your usual level of stress on top of it, it's easy to see how the problem could compound into anxiety. When the scenario repeats itself day after day, the anxiety can become chronic.
Practicality
You don't necessarily have to give up your morning java fix to stop the anxiety. Practice relaxation techniques like yoga and meditation to decrease your everyday stress, and get regular aerobic exercise to help exhaust some of that extra energy. Keep the caffeine consumption within reason -- when you start feeling jittery, you've had too much -- and don't consume caffeine within six hours of bedtime to avoid disrupting your sleep cycle, which can worsen symptoms of stress and anxiety.
References
- University of Minnesota; How Does Caffeine Work in the Brain?; Mandy Lind
- University of Washington: Neuroscience for Kids: Caffeine
- "Scientific American"; How Does Caffeine Affect the Body?; Neal J. Smatresk; Feb. 15, 1999
- "Pharmacological Reviews"; Actions of Caffeine in the Brain With Special Reference to Factors That Contribute to its Widespread Use; Bertil Fredholm, et al.; March 1999
