When people consume caffeine regularly, according to Dr. Melissa Stoppler of medicinenet.com, withdrawal from caffeine can produce symptoms like those of withdrawal from other addictive substances (e.g., headaches, irritability, nausea, muscle pain and problems with concentration). Dr. Stoppler adds that addiction can occur with as little as one cup of coffee a day.

On the Other: Caffeine in Decaffeinated Coffee

A University of Florida study showed that almost all decaffeinated coffee contains some caffeine. Five to 10 cups of decaffeinated coffee can easily have as much caffeine as a cup or two of regular coffee, according to U.F. Professor Bruce Goldberger, and as little as 10 milligrams can produce behavioral effects in some people. People can develop a physical dependence on decaffeinated coffee, states coauthor Dr. Mark Gold.

Bottom Line

People don't think of caffeine as an addictive drug because it doesn't have the negative effects of other drugs, says Roland Griffiths, professor at Johns Hopkins University, but the way people become addicted to it is the same. According to the National Institute on Drug Abuse, effective treatment for drug addiction needs to help the individual "stop using drugs" and maintain a "drug-free lifestyle."

Source:

MedicineNet: Caffeine Addiction, Can You Quit?

University of Florida News: Decaffeinated Coffee Is Not Caffeine-Free

MayoClinic.com: Caffeine: How Much Is Too Much?

Resource:

National Institute on Drug Abuse: NIDA InfoFacts: Treatment Approaches for Drug Addiction

MindBodyFocused.com: Caffeine Addictions in Today's Coffee Culture

U.S. News and World Report: 6 Signs of Caffeine Addiction