Editor's Note: With the release of the latest edition of the mental health manual, the Diagnostic and Statistical Manual of Mental Disorders (the DSM), LiveScience takes a close look at some of the disorders it defines. This series asks the fundamental question: What is normal, and what is not?
Coffee-drinkers, beware: Your caffeine habit could induce a temporary mental disorder. The new edition of the mental health manual, the DSM-5, lists caffeine intoxication among the many disorders known to psychiatry.
Restlessness, nervousness, excitement, red face, gastrointestinal upset, muscle twitching, rambling speech, sleeplessness, rapid and irregular heartbeat and other symptoms may be familiar to many of us, but they are telltale signs of caffeine intoxication.
Specifically, a coffee drinker who experiences five or more of these symptoms during or shortly after consuming caffeine could be diagnosed with caffeine intoxication. The intoxication must also meet a standard DSM test: It must cause distress or impair the drinker's ability to function. [10 Odd Facts About Coffee]
This condition appears in both the old edition of the Diagnostic and Statistical Manual of Mental Disorders(DSM-IV) and the new DSM-5, but the new version, officially released Thursday (May 22), adds a related diagnosis: caffeine withdrawal, which describes the effects of stopping or dramatically reducing the pick-me-up habit.
Withdrawal symptoms include headache, fatigue, difficulty concentrating, depressed mood and other issues.
Caffeine is the most widely used, behaviorally active drug in the world, and some consumers may be unaware of their physical dependence on it, the DSM-5 notes.
"The symptoms of caffeine withdrawal are transitory, they take care of themselves," said Robin Rosenberg, a clinical psychologist and co-author of the psychology textbook "Abnormal Psychology" (Worth Publishers, 2009). "It's just a natural response to stopping caffeine, and it clears up on its own in short order."
The more long-standing diagnosis of caffeine intoxication also describes a temporary state, Rosenberg said, adding that she does not understand why either is included in the DSM.
Alan Budney, who served on the DSM-5 working group for substance-use disorders, explained the rationale for including caffeine withdrawal to Medscape Medical News in 2011.
"Caffeine is invading our society more and more. So there's concern enough to consider this topic seriously, even though it's probably one of the more controversial issues faced by our work group," said Budney, a clinical psychologist and professor of psychiatry at the University of Arkansas for Medical Sciences.
Caffeine withdrawal can affect someone's sleep, work and other aspects of his or her life, he said.
Typically, caffeine is used as a performance-enhancing substance. A bitter-tasting stimulant, it revs up the central nervous system, ideally making someone feel awake, alert and energetic. Caffeine is found in coffee, tea and chocolate, and is added to headache medication, energy and alcoholic beverages, and even water.
Everyone from athletes to morning commuters to people looking to get in a long night of partying take advantage of this stimulant. Some benefits, such as a reduced risk of some cancers, have been linked to coffee drinking, but its active ingredient, caffeine, can also harm. In rare cases when consumed at high enough doses, caffeine can kill.
Between 2005 and 2009, emergency room visits associated with the consumption of caffeine-laden energy drinks, often in combination with alcohol and other drugs, increased tenfold.
Of course, caffeine is not the only chemical that can intoxicate. The DSM groups this disorder with others associated with substances ranging from alcohol and nicotine to cannabis and hallucinogens. The use of mind-altering substances like these can alter behavior, mental processes and cause physical symptoms.