Miss your morning cup of coffee and get a pounding headache? Feel grumpy if you haven't had a cup of Joe in hours? Caffeine addiction is easy to develop and hard to kick. Though caffeine is prevalent and legal, it's the most commonly used drug in the world. In addition to coffee, it can lurk in soda, tea, energy drinks, chocolate, gum, vitamins, snacks like "caffeinated peanuts," and even some over-the-counter medicines. Last year, "caffeine withdrawal syndrome" was recommended for inclusion in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), which is used by mental health professionals to diagnose and research disorders. That's because caffeine can alter mood and behavior and caffeine withdrawal can interfere with sleep, work, and the ability to function at peak capacity. (The proposed revision has not yet been approved.)
"People are hesitant to think of [caffeine] as a drug of addiction because it doesn't have a lot of the health and adverse social consequences associated with our classic drugs of addiction," says Roland Griffiths, a professor in the departments of psychiatry and neuroscience at the Johns Hopkins School of Medicine. "Yet the basic mechanisms by which it hooks people are very much like our classic drugs of addiction."
Most people experience mild to modest withdrawal, Griffiths says, which is relieved by drinking coffee in the morning after abstaining from it overnight. Many people say, "'I really don't get going until I have coffee, [and] then I feel great.' What they're not recognizing is that if they didn't consume coffee [at all], they would wake up feeling great," Griffiths says.
Griffiths' research suggests that it only takes 100 milligrams of caffeine a day—the amount found in a moderate-strength 8-ounce serving of coffee—to trigger at least mild withdrawal symptoms. And coffee isn't the only culprit—any type of caffeine can cause withdrawal. Caffeine withdrawal symptoms typically appear 12 to 24 hours after abstaining from coffee, and peak within 24 to 48 hours. They include: headache; lethargy and drowsiness; depressed mood; anxiety; nausea; vomiting; muscle pain and stiffness; and inability to concentrate. For those who are more caffeine-sensitive, symptoms could begin within three hours and last for up to a week. Those with the heaviest habit usually experience the most severe side effects.
More severe than caffeine addiction and withdrawal? Caffeine intoxication. It's a recognized clinical syndrome that causes nervousness, anxiety, restlessness, insomnia, stomach problems, tremors, rapid heartbeat, restlessness, and pacing. It can even lead to death. Caffeine intoxication cases typically stem from caffeine pills and overdosing on energy drinks, though the DSM defines caffeine intoxication as recent consumption of more than 250 mg. of caffeine (about two to three cups) coupled with five or more symptoms that occur during or shortly after caffeine use.
Luckily, kicking the habit is doable. Most experts suggest cutting back gradually, drinking one fewer can of soda or a smaller coffee each day. That helps your body adjust to lower levels of caffeine, lessening potential withdrawal effects. Opting for decaf coffee or green tea is also smart, as is keeping a written tally of caffeine consumption each day.
Updated on 4/17/2012: This story was originally published on June 25, 2009. It has been updated by Angela Haupt.