Anxiety and Caffeine Consumption

Caffeine’s High Anxiety

Some brains are extremely sensitive to caffeine. In fact, caf­feine-induced anxiety is far more common than realized. One study showed that 30 percent of adult users reported anxiety due to caffeine. As little as 250 milligrams a day—only two-and-a-half cups of coffee—can trigger anxiety in ordinary people. Much less may can trigger or aggravate anxiety and panic attacks in those particularly vulnerable to the disorder. Research at the National Institute of Men­tal Health even found that a dose of 750 milligrams (seven to eight 5-ounce cups of coffee) a day induced panic attacks in two of eight normal subjects with no history of panic disorder. Recent British studies show that caffeine worsens social anxiety.

Moreover, in susceptible individuals, only five or six cups of coffee a day can produce so-called “caffeine intoxication,” a psychiatric disorder characterized by nervousness, excite­ment, restlessness, tachycardia (irregular heartbeats), insomnia, psychomotor agitation, and rambling thought and speech. Some people’s brains are simply unable to tol­erate caffeine.

“Some people may really need drugs to alleviate anxi­ety, but for an undetermined number of others, sub­tracting one drug—caffeine–may be of greater benefit than adding another.”—John F. Greden, M.D., formerly of Walter Reed Army Medical Center

How your brain reacts to caffeine may be inherited. One recent study suggests that heredity may account for one-third to one-half of your tolerance for caffeine and whether you suffer withdrawal symptoms. Recent brain scans reveal that individuals who are intolerant to caffeine metabolize caffeine differently. A new study compared the brain scans of heavy caffeine users and those intolerant to caffeine.

The caffeine-intolerant reacted with “moderate to marked anx­iety” when given the caffeine in about five cups of coffee for a 120-pound person. Also, brain scans showed distur­bances in the way they metabolized caffeine; production of a specific brain chemical increased and blood flow to cer­tain regions of the brain decreased. Such biological signs may help explain how caffeine produces anxiety and psy­chological distress in some people, researchers said.

“Caffeine, the most widely used behaviorally active drug in the world, produces very different reactions in different individuals.” —Larry Christensen, Ph.D., Uni­versity of South Alabama