Caffeine can sometimes cause effects similar to symptoms of anxiety, including nervousness and a fast heart rate. If you have too much, you may also get caffeine-induced anxiety.

Caffeine is the most popular and widely-used drug in the world. In fact, 85 percent of the U.S. population consumes some every day.

But is it good for everyone?

According to the National Institute of Mental Health, about 31 percent of U.S. adults will at some point in their lives experience an anxiety disorder. Does caffeine affect — or even cause — anxiety?

There is an association between caffeine ingestion and mental health.

In fact, the Diagnostic and Statistical Manual of Mental Disorders (DSM–5) — the guide published by the American Psychiatric Association and used by healthcare professionals for the diagnosis of mental disorders — currently lists four caffeine-related disorders:

  • caffeine intoxication
  • caffeine withdrawal
  • unspecified caffeine-related disorder
  • other caffeine-induced disorders (anxiety disorder, sleep disorder)

A 2008 study showed how caffeine increases alertness by blocking a brain chemical (adenosine) that makes you feel tired, while at the same time triggering the release of adrenalin that’s known to increase energy.

If the amount of caffeine is high enough, these effects are stronger, resulting in caffeine-induced anxiety.

While there are mental benefits to caffeine, high doses are known to induce anxiety symptoms, and people with panic disorder and social anxiety disorder are especially sensitive.

A 2005 study noted that excessive caffeine consumption can lead to symptoms similar to psychiatric conditions including sleep and anxiety disorders, increasing hostility, anxiety, and psychotic symptoms.

According to Harvard Medical School, caffeine use can mimic symptoms of anxiety.

The caffeine-induced symptoms that can mirror anxiety include:

If you’re accustomed to regularly consuming caffeine, and abruptly stop, you can experience withdrawal symptoms, such as:

Caffeine withdrawal is not considered dangerous like withdrawal from opioids, but it can be difficult and distressing.

Consider talking to your doctor for suggestions on how to cut back gradually, including getting enough sleep and exercise, and staying hydrated.

The concentration of caffeine varies depending on the type of beverage, the quantity, and the brewing style.

Below are ranges of caffeine contents in popular beverages:

  • 8 ounces of decaf coffee contains 3–12 mg
  • 8 ounces of plain black coffee contains 102–200 mg
  • 8 ounces of espresso contains 240–720 mg
  • 8 ounces of black tea contains 25–110 mg
  • 8 ounces of green tea contains 30–50 mg
  • 8 ounces of yerba mate contains 65–130 mg
  • 12 ounces of soda contains 37–55 mg
  • 12 ounces of energy drinks contain 107–120 mg

According to the U.S. Food and Drug Administration (FDA), 400 milligrams a day, which translates to about 4 cups of coffee, typically doesn’t result in negative or dangerous effects for healthy adults.

The FDA also estimates that around 1,200 mg of caffeine can result in toxic effects, such as seizures.

When reviewing these figures, keep in mind that there are wide variations in different people’s sensitivities to the effects of caffeine and the speed they metabolize it.

If you take any medications, they may also be affected by caffeine consumption. Speak to your doctor if you have any concerns.

There’s an association between caffeine consumption and anxiety including caffeine-induced anxiety disorder. Yet, for most people, moderate caffeine intake is safe and may have benefits.

Cutting back or eliminating caffeine from your diet quickly can lead to withdrawal symptoms, which can also be anxiety producing.

If you feel that your anxiety is increasing due to caffeine, or it’s making you feel anxious, speak to your doctor about the right amount for you.