Caffeine has properties of an addictive drug, Hopkins study finds

October 05, 1994|By Jonathan Bor | Jonathan Bor,Sun Staff Writer

Kathy Rossiter was feeling the early twinges of labor several years ago when she confronted the unthinkable: no more Mountain Dew in the house. Even though her baby was on the way, she feared caffeine withdrawal, so she rushed to the grocery store and bought two six-packs.

This didn't seem an extreme measure to feed a caffeine habit until she was standing at the cashier's counter, labor pains mounting while she waited her turn to pay.

"People were looking at me askance," said Ms. Rossiter, 38, a nurse who lives in Fullerton. "I started to think, 'This is not a smart thing to do.' The pains were coming. 'What if the baby comes sooner?' "

Although nothing bad happened -- she delivered safely several hours later -- her case illustrates what caffeine researchers at the Johns Hopkins School of Medicine found in a new study: Caffeine, the most widely used mood-altering substance in the world, meets the technical definition of a drug of dependence.

"Caffeine creates problems that are similar to those produced by classic drugs of abuse," said Dr. Roland R. Griffiths, a professor of psychiatry and neuroscience and co-author of an article in today's Journal of the American Medical Association.

"People should recognize that caffeine is a drug and give caffeine appropriate respect as a drug."

The researchers advertised for volunteers who considered themselves hooked on caffeine.

After interviewing 27 people who responded, the researchers found 16 who could be described as physically and psychologically hooked -- meeting at least some conditions for dependence established by the bible of psychiatry, the Diagnostic and Statistical Manual of Mental Disorders.

* They suffered headaches, nausea and other withdrawal symptoms when they tried to cut back.

* They needed increasing doses to achieve the same level of alertness.

* They flopped in past efforts to reduce or quit their habits.

* And, like Ms. Rossiter, they continued to use caffeine despite medical and psychological problems made worse by the chemical.

"Interestingly, a number of physicians had recommended that subjects eliminate caffeine because of medical conditions they had -- skin conditions, stomach conditions, heart conditions and pregnancy," Dr. Griffiths said.

Despite these warnings, the volunteers persisted.

Caffeine, a stimulant as ancient as the Chinese teas of 4,000 years ago, is found in coffee, tea, colas, chocolate, analgesics and soft drinks such as Coke, Pepsi, Dr Pepper and Mountain Dew.

While scientific studies have yet to prove that caffeine produces medical problems beyond sleeplessness, many doctors believe that it can exacerbate conditions that may or may not have caffeine as their cause. In the Hopkins study, seven of the volunteers continued to reach for coffee, tea or soft drinks despite doctors' warnings to stop.

Volunteers' troubles

One volunteer had acne rosacea, a chronic condition in which the nose and cheeks become abnormally red.

Others had heart palpitations or stomach problems.

And Ms. Rossiter was pregnant. Many obstetricians recommend that pregnant women abstain from caffeine in the face of evidence -- some disputed -- that heavy caffeine intake may cause birth defects.

In a sharp rebuke to the Hopkins study, a consultant to the industry-funded International Food Information Council said that most scientists investigating the possible adverse effects of caffeine have found that none exist.

The consultant, Dr. Peer Dews, an emeritus professor of psychiatry at Harvard University, also said that the study was tainted because more than half of the research subjects had a history of psychiatric illness or substance abuse.

But Dr. Griffiths said that only two had a continuing psychiatric problem, while the rest had been successfully treated and were no longer ill.

Surveys of the general population, he said, show that about half of all people have suffered a psychiatric disturbance at one time or another.

Also, he said, one-third of the volunteers had no history of emotional problems or substance abuse, including Ms. Rossiter, whose caffeine cravings have increased in recent years.

Today, she drinks six 16-ounce bottles of Mountain Dew a day -- the caffeine punch of about four cups of strong coffee.

He said he didn't want to trivialize the harrowing problems caused by such addictive substances as cocaine, heroin, alcohol and nicotine by suggesting that caffeine ranks in the same league.

For many people, addiction's biggest curse may be withdrawal symptoms that can rise when they miss their fix.

This keeps them mired in a cycle of dependence, forever feeding their habit to avoid feeling low.

But he said people who are advised to stop because of underlying medical conditions -- but can't -- should realize the nature of their problem.

Withdrawal pains

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