If you missed your morning coffee and now you have a
headache and difficulty concentrating, you might be able to
blame it on caffeine withdrawal. In general, the more
caffeine consumed, the more severe withdrawal symptoms are
likely to be, but as little as one standard cup of coffee a
day can produce caffeine addiction, according to a Johns
Hopkins study that reviewed more than 170 years of caffeine
withdrawal research.
Results of the Johns Hopkins study should result in
caffeine withdrawal being included in the next edition of
the DSM, the Diagnostic and Statistical Manual of Mental
Disorders, considered the bible of mental disorders,
and the diagnosis should be updated in the World Health
Organization's ICD, or International Statistical
Classification of Diseases and Related Health Problems.
"Caffeine is the world's most commonly used stimulant,
and it's cheap and readily available, so people can
maintain their use of caffeine quite easily," says Roland
Griffiths, professor of
psychiatry and
neuroscience in the School of Medicine. "The latest
research demonstrates, however, that when people don't get
their usual dose, they can suffer a range of withdrawal
symptoms, including headache, fatigue, difficulty
concentrating. They may even feel like they have the flu
with nausea and muscle pain."
Griffiths, and colleague Laura Juliano of American
University, published these findings in the October issue
of the journal Psychopharmacology, available online
now.
"Despite more than a century and a half of
investigation into caffeine withdrawal, doctors and other
health professionals have had no scientifically based
framework for diagnosing the syndrome," Griffiths says.
"Our goal was to critically review the literature regarding
caffeine withdrawal to validate the symptoms and signs of
illness associated with it and to determine how often
withdrawal produced clinically significant distress."
In their review, the researchers identified 57
experimental studies and nine survey studies on caffeine
withdrawal and examined each to assess the validity of the
reported findings.
The researchers identified five clusters of common
withdrawal symptoms: headache; fatigue or drowsiness;
dysphoric mood, including depression and irritability;
difficulty concentrating; and flulike symptoms of nausea,
vomiting and muscle pain or stiffness. In experimental
studies, 50 percent of people experienced headache and 13
percent had clinically significant distress or functional
impairment — for example, severe headache and other
symptoms incompatible with working. Typically, onset of
symptoms occurred 12 to 24 hours after stopping caffeine,
with peak intensity between one and two days and for a
duration of two to nine days. In general, the incidence or
severity of symptoms increased with increases in daily
dose, but abstinence from doses as low as 100 milligrams
per day, or about one small cup of coffee, also produced
symptoms.
The research also showed that avoidance of caffeine
withdrawal symptoms motivates regular use of caffeine. For
example, the satisfying feelings and perceived benefits
that many coffee users experience from their morning coffee
appear to be a simple reversal of the negative effects of
caffeine withdrawal after overnight abstinence.
But there is good news for those wishing to quit
caffeine: A simple, stepwise approach can often eliminate
the need for a "fix" without suffering the most severe
withdrawal symptoms.
"We teach a systematic method of gradually reducing
caffeine consumption over time by substituting
decaffeinated or noncaffeinated products. Using such a
method allows people to reduce or eliminate withdrawal
symptoms," Griffiths says.
According to the report, caffeine is the most widely
used behaviorally active drug in the world. In North
America, 80 percent to 90 percent of adults report regular
use of caffeine. Average daily intake of caffeine among
caffeine consumers in the United States is about 280
milligrams, or about one to two mugs of coffee or three to
five bottles of soft drink, with higher intakes estimated
in some European countries. In the United States, coffee
and soft drinks are the most common sources of caffeine,
with almost half of caffeine consumers ingesting caffeine
from multiple sources, including tea.
The study was funded in part by the National Institute
on Drug Abuse.