Caffeine Addiction, Abuse and Dependency
What is caffeine?
Caffeine content in typical products
Caffeine is a chemical substance, central nervous system stimulant, ingredient of several drinks and foods like brewed and instant coffee, tea, caffeinated water and soda drinks. It's also an addition to many stimulants, aids, weight loss helpers and sports nutrition. It is a common mistake to take caffeine, theine (natural tea ingredient) and guaranine (often in drinks) as something completely different. Please note, that this words are just other names of caffeine. Hence, you should always consider intake of caffeine with regard to eventual significant tea and energy drinks consumption cause because all of them may lead to caffeine addiction. Caffeine molecule looks like this:
caffeine molecule
Caffeine content varies strongly depending on the type of product. Main natural source of caffeine is coffee espresso with caffeine content about 250 mg / 6 oz. Espresso however is usually consumed in small amounts. Next one is brewed coffee with caffeine content about 100 mg / 6 oz. Instant coffee is 'healthier' and consists 70 mg / 6 oz. For people who are afraid of caffeine addiction and dependency consumption of decaffeinated coffee may be a solution. Such a beverages contain only 4 mg of caffeine / 6 oz, what is even smaller than caffeine content in tea, which is about 35 mg / 6 oz. Other than natural sources of caffeine are: caffeinated soda (20 mg / 6 oz), dark and milk chocolate (20 mg / 1 oz and 6 mg / 1 oz respectively), stimulants, weight-loss aids, energy drinks (Red Bull contains 80 mg of caffeine per can), sports nutrition and others.
some useful data on caffeine in 'Harmful Chemical Substances Catalog'
Caffeine use and abuse
As you know, caffeine use is fully allowed and popular. You should know that it is most widely used psychoactive substance in the world! Striking, isn't it? Mass of coffee sold every year is about 7 000 000 kg. Hughes and Oliveto (1997) investigated that 80-90% of people of North America consume caffeine including foods or drinks at least once a week; and average daily caffeine consumption in U.S. is 280 mg per person per day among regular caffeine users. Caffeine amount consumed daily depends on culture and nation and is believed to be typically between 80 to 480 mg. As Daly and Fredholm say in article published in 1998:
Caffeine has both positive effects that contribute to widespread consumption of caffeine-containing beverages and adverse unpleasant effects if doses are increased.[1]
Caffeine as a psychoactive substance can produce a variety of syndromes and psychological effects and physicians – although it's often difficult – are able to recognize caffeine overdose or intoxication and such a disorders like: caffeine dependency (caffeinism), caffeine withdrawal and commonly known caffeine-induced sleep disorder and anxiety disorder.
Effects of caffeine addiction are not specific. It's rather hard for physicians (at first sight) to consider it as related directly to caffeine. Hence, initially your own recognition is of great importance. Caffeine is a typical element of our culture and many symptoms – results of caffeine addiction, intoxication, dependence or withdrawal signs may be simply recognized by us as a sings of for example, the so-called 'bad day'.
There are some situations when caffeine use is not recommended by physicians including: pregnancy, arrhythmia, tachycardia, palpitations, anxiety, insomnia, digestive track disturbances, and others.
Tolerance to caffeine
Tolerance to caffeine is strong and fast developing and people who drink a lot of coffee regularly are caffeine-tolerant (according to research data 75% of caffeine dependent individuals report significant signs of tolerance (Strain et al., 1994)). As a consequence, for example an intoxication is less probable and requires relatively large dose to be intaken at once. However, caffeine-tolerant people are at the highest risk of caffeine addiction and all of its negative health consequences.
Medical researches show that tolerance varies depending on the given effect of use – some of them exhibit response changes due to caffeine tolerance and the other effects do not change. When we consider for example sleep and mood behavior it seems not to be altered by tolerance. However, strong caffeine tolerance was observed with caffeine abuse effects on cardiovascular and respiratory systems and their running.
what is tolerance and withdrawal?
Evaluation of caffeine addiction
Evaluation of caffeine addiction relies on interview with patient who have to tell how large and how frequent his caffeine use is. This interview does not only touches coffee consumption but also all other sources of caffeine are considered (beverages, medicaments, drug, energy tablets, capsules and drinks, diet aids / pills). Because of that patient possibly may not know products (other than coffee) that consist caffeine – all is in physician's hand to make a good interview. And a good interview will be a source of appropriate and useful information, so important in further treatment.
Caffeine intoxication and overdose
- nervousness / excitement,
- and restlessness / insomnia,
- periods of inexhaustibility,
- flushed face,
- psychomotor agitation and muscle twitching,
- increased production of urine,
- digestive track disturbances,
- tachycardia or cardiac arrhythmia,
- pounding sound,
- rambling flow of speech.
Caffeine intoxication occurs when a large dose of caffeine was taken at once – usually 250 mg or more for abusers and even 100 mg for those who do not drink coffee regularly or never did before (difference occurs because of tolerance mechanism which develops in organisms of people who use or abuse caffeine, as I've mentioned before). Single intoxication incident is of course much more possible among people who do not use caffeine chronically, but syndromes of abuse, which I've listed above, may also occur when intake of smaller doses of caffeine is regular and goes on long time. Intoxication may last for few hours. However, apart from physical signs, we have on the other hand, some effects due to psychoactivity of caffeine. This molecule is an antagonist acting in the adenosine receptor, thus produces some physiological effects like:
- decreasing spontaneous electrical activity in brain,
- inhibiting neurotransmitter release in brain,
- decreasing spontaneous and operant motor activity,
- dilating central vasculature,
- producing antidiuresis,
- inhibiting renin release, gastric secretion and lipolysis.
Although fatal caffeine overdose is a quite rare incident and requires extremely large dose to be intaken – over 5 g of caffeine – there are some evidences of deaths due to caffeine overdose. Kerrigan and Lindsey reports such incidents in their article published in 2005. First case was 39-year-old female found outside a restaurant and the second one: 29-year-old male who had taken from his family home a bottle of caffeine pills the day before and misused it. Authors underline, however, that there was an incident of successful recovery after ingestion of 30 g of caffeine. They conclude:
Fatal caffeine overdose is relatively uncommon. However, we report two cases: one, which may have resulted from misidentification of the drug and another that appears to involve misuse of a dietary supplement. In both cases, the cause of death was attributed to caffeine intoxication and the manner of death was accident.[2]
Caffeine dependency
Caffeine dependency may develop when caffeine consumption is chronic and long in time, i.e. caffeine addiction develops. Due to the habits of modern world most of us are in risk of this disorder. Tolerance to caffeine develops fast and evidences of caffeine addiction, both of psychological and physical (physiological) nature, arise soon. Main feature of caffeine dependency is inability to quit caffeine consumption habit, experienced by majority of investigated patients. The consequence among caffeine-dependent people are negative caffeine withdrawal syndromes which arise when appropriate dose of caffeine was not provided to organism.
Consumption of caffeine (in any form, though mainly coffee and energy drinks) is a stable habit or every-day ceremony in many cultures. According to scientific investigations regular coffee drinking very often occurs simultaneously with tobacco smoking and or alcohol drinking. Swanson et al. (1994) noticed that cigarette smokers use more caffeine that others. Interestingly, some research suggest that our fondness to caffeine has its origins in our genes (Kendler, Prescott, 1999).
Symptoms of caffeine dependency are equal to those observed during intoxication and caffeine withdrawal.
Caffeine withdrawal
Caffeine withdrawal recognition depends on interview with patient to get to know if caffeine addiction was present in his/her life before and if abrupt reduction of caffeine use has happened one time. Generally speaking recognition may be hard because most people do not think about caffeine abuse as about a disease. However, withdrawal symptoms may occur most intensively between 12 to 48 hours after the latest caffeine use and sings, listed below, may last from 2 to 7 days:
- headache,
- anxiety and irritability,
- nausea or vomiting,
- fatigue and sluggishness,
- sleepiness, drowsiness,
- difficulty concentrating and work difficulty,
- depression,
- muscle aches.
Caffeine addiction treatment
Treatment of caffeine addiction is all about psychological therapy and aid. There's no medical help and medicaments for caffeine abuse.
References
[1] Daly JW, Fredholm BB; Caffeine – an atypical drug of dependence, Drug and Alcohol Dependence, 1998, 51, 199
[2] Kerrigan S, Lindsey T; Fatal caffeine overdose: Two case reports, Forensic Science International, 2005, 153, 67
