When I started to work on the article, exploring causal relationship between coffee and depression, I was not quite sure what category this post will belong: to the depression causes, or to the depression cures. There is no doubt, that there should be some link between these two. To my surprise, the amount of studies trying to examine the relationship is quite limited, and the results, and following recommendations are quite controversial. Following the detailed review of all the materials, I decided to place the post in the cure category, and I will try to explain this decision.
How Coffee Works on your Body and Mind?
When you drink coffee, or any other caffeinated drink, as a matter of fact, whether it's a soft drink, caffeinated tea or energy drink – the caffeine uptake will put your body on the special internal rollercoaster. Upon consumption, caffeine begins its effects by initiating uncontrolled neuron firing in your brain. This excess neuron activity triggers your pituitary gland to secrete a hormone that tells your adrenal glands to produce adrenalin. Therefore, caffeine puts your body in this "fight-or-flight" state, which might not be quite necessary for you risk-free daily job at your computer desk. And there is a payout coming later. When this adrenal high wears off, you feel more fatigue, irritability, headache or confusion.
Stephen Cherniske in his book, Caffeine Blues explains your body's "perspective" of this constant state: "Imagine you lived in a country that was always under threat of attack. No matter where you went, there was a perpetual state of alert. Not only that, but your defenses were constantly being depleted and weakened. Does that sound stressful? Caffeine produces the same effect on your body, like fighting a war on multiple fronts at the same time." Cherniske calls your body's constant state of alert "caffeinism," which is characterized by fatigue, anxiety, mood swings, sleep disturbance, irritability and depression.
A dosage of 50 to 100 mg caffeine, the amount in one cup of coffee, will produce a temporary increase in mental clarity and energy levels while simultaneously reducing drowsiness. It also improves muscular-coordinated work activity, such as typing. Through its CNS stimulation, caffeine increases brain activity; however, it also stimulates the cardiovascular system, raising blood pressure and heart rate. It generally speeds up our body by increasing our basal metabolic rate (BMR), which burns more calories.
Can Caffeine Cause Depression?
After reviewing the coffee effect on the body, it would seem more likely, that caffeine would cause anxiety rather than depression – which is true for some people. On the other hand, there is a possibility that caffeine makes the symptoms of depression worse in several ways. One way is by increasing levels of the stress hormone cortisol – a hormone produced by the adrenal gland that’s associated with feelings of depression.
Other consideration should be taken in an account. Caffeine usually increases energy levels and boosts alertness initially, but this is followed several hours later by a “crash” where a person feels fatigued and wiped out. In a person who’s already depressed, this can make the symptoms worse – or lead to a cycle of drinking caffeine all day just to stay functional. Caffeine also causes rapid fluctuations in blood sugar levels which can worsen the symptoms of depression.
Validity of these warnings has been confirmed by research results, completed in Kansas State University, checking the hypotheses that drinking caffeinated coffee can lead to feelings of depression. Commenting on the study results, scientists explained that caffeine only increases energy temporarily. When caffeine is consumed, it begins to lower the level of sugar in the body's blood supply. About 4 hours after drinking the coffee, the body experiences significantly low blood sugar levels, which causes feelings of depression and fatigue.
And finally multiple studies have proven that stopping abruptly caffeine consumption can worsen depression if you regularly consumed it before, remaining regular withdrawal symptoms in the process of cleansing from other drugs as nicotine, for example. Quitting caffeine can also cause other signs and symptoms such as headaches, fatigue and irritability.
Coffee as Mild Antidepressant
To be fair, we should also present another side of a story. Several recent studies have shown that coffee may function as an antidepressant, acting on the central nervous system and has mild antidepressant effects.
Coffee and Depression studies have found that drinking coffee reduced the rate of suicide in the large demographic populations observed.
The first study that raised the topic of coffee as an antidepressant was done in 1993. In this study, which included the relationship between Coffee and Depression, Kaiser Permanente Medical Care Program studied 128,934 nurses and found that coffee drinkers were significantly less likely to commit suicide than nondrinkers. This Nurse’s Health Study did not go so far as to establish a causal relationship between coffee drinking and the drop in the suicide rate as far as coffee and depression goes. The study stated that it could be that the coffee itself had little to do with it, but that people who drink coffee share other characteristics that make them less likely to commit suicide.
A second study on coffee including this relationship confirmed these controversial findings and went farther as to state that it was the coffee that dropped the suicide rate. This study was especially noteworthy, as it was large-scale and adjusted for a wide range of other factors.
Published in the Archives of Internal Medicine in 1996, the study followed more than 86,000 registered nurses in the United States between 34 and 59 years of age for ten years. Dr. Ichiro Kawachi, an epidemiologist at Harvard Medical School who led this study, looked at the data from the Kaiser study hoping to dispute their findings. Instead of what he expected to find, he confirmed the original study’s results with his own: using coffee as an antidepressant reduced the suicide rate in these nurses.
Dr. Kawachi discovered that the nurses he studied who drank two to three cups of coffee a day were one-third less likely to commit suicide as those who didn't drink any. The nurses who drank more than four cups of coffee a day were 58% less likely to commit suicide than their colleagues who drank less. This study of female nurses found eleven suicides among those who drank two to three cups of caffeinated coffee per day, compared with twenty-one cases among those who said they almost never drank coffee.
Dr. Kawachi suggested that whether it is the caffeine or some other coffee ingredient, coffee does seem to have at least a mild antidepressant effect. The caffeine in coffee may have mood-elevating actions through effects on neurotransmitters such as dopamine and acetylcholine.
Summary
1. Moderate amount of the caffeinated drinks consumption may have slight positive effect on the depressive symptoms appearance, especially for people performing the stressful and complicated job functions. Mild antidepressant and stimulating effect helps the body to “wake up” and got to work. Moderation is a key, since excessive amount of the daily dose of caffeine may cause the body to get “over burnt”, draining physical and emotional energy out.
2. The Mayo Clinic suggested that there is still no substantial link been found connecting directly caffeine and depression. Instead, the depression may be linked to a lack of sleep related to caffeine. Having a good night sleep is very important, so do not drink coffee or any other caffeinated drinks in the evening. It is recommended to confine your coffee drinking to before noon as a general rule.
3. Depression symptoms may occur as a result of caffeine withdrawal, especially among people who consume caffeine regularly. An individual withdrawing from caffeine because of a chronic toxic overdose may experience symptoms of withdrawal including headache, nausea, nervousness, reduced alertness and depressed mood. These symptoms are most acute during the first 20-48 hours, but they may persist for as long as 7 days. Discontinuation of caffeine at even a moderate intake can lead to these symptoms.
4. While proven link between caffeine and depression has to be discovered yet, scientists claim that there should be no relations between decaffeinated coffee and depression symptoms, focusing on caffeine as the primary troublemaker.
5. And final, but very important point: if you drink coffee, at least do not feel guilty about that!
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