The effect of caffeine on anxiety

A 1992 study of caffeine's effects on anxiety concluded that "caffeine increases anxiety only at doses of 300 milligrams or more, many times the caffeine content of a cup of coffee." Small amounts of caffeine do not cause anxiety, and even in some special cases small amounts of caffeine can reduce anxiety."

Since that review appeared, two studies have shown that high caffeine intake can cause anxiety. So 600 milligrams of caffeine (2) or multiple cups of coffee (3) containing 125 milligrams of caffeine per cup can increase anxiety. Caffeine intoxication, defined as a group of symptoms associated with daily caffeine intake of 1000 to 1500 mg, closely resembles symptoms of severe chronic anxiety disorder.

However, there is no evidence in the literature that caffeine intake causes anxiety. Several intervention experiments with moderate doses of caffeine have shown that caffeine has no anxiety effect on normal individuals or on psychiatric patients with anxiety disorders themselves. And there is no evidence that caffeine increases anxiety caused by other stressors. Therefore, there is no reason to modify it.