spaziatore

Gettings Back In Sync:Tips On Overcoming Jet Lag And SAD

spaziatore
spaziatore
spaziatore
spaziatore
layout...
layout...
layout...
layout...
spaziatore
spaziatore
spaziatore
spaziatore
Our circadian rhythm is the day/night cycle that regulates our major life- sustaining activities, including when we sleep, when we wake, and when we eat. Our body is governed by dozens of interrelated cycles produced by "internal clocks" which work together to synchronize us to the world around us. Internal rhythms control and coordinate our production of enzymes and hormones, which in turn control hunger, mood, body temperature, and energy level.The pineal gland is the key to maintaining the normal functioning of our internal clocks. It works in sync with another body clock, the superachiasmatic nuclei, a cluster of nerve cells situated in another key center of the brain, the hypothalamus. Each day, light that passes through the eye sets the timing mechanism of the pineal gland. At night, the pineal gland interacts with the suprachiasmatic nucleus, sending messages alerting our body that it is dark. The pineal gland, aware of darkness, begins to secrete melatonin. The fluctuation in melatonin regulates the day/night cycles. Other hormone working in sync with melatonin control our body´s other rhythms. Light  suppresses melatonin production; therefore, the duration of daylight, and even seasonal changes in day length, can affect the ebb and flow of melatonin.At times, our natural body cycles may be disrupted. Traveling across time zones, for example, can cause jet lag, a common complaint that is triggered by a disturbance in day/night cycles. Seasonal affective disorder (SAD) is another common problem involving a disruption of circadian cycles that occurs in temperate climates during the winter. People with SAD are sensitive to the lengthened periods of darkness in winter, which can alter their melatonin cycling, and create psychological and physical problems associated with depression. In this chapter, I will discuss how and why we fall out of sync, and what to do to get back on track.

spaziatore
spaziatore
spaziatore
spaziatore
Jet lag

Jet lag is a recent phenomenon. At the turn of the century, the mere suggestion that we could zoom across time zones faster than our bodies could adjust to the time change would have seemed like a scenario straight out of Jules Verne. Now that jets have replaced trains and cruise ships as the most common mode of long- distance travel, skipping time zones has become commonplace. So has jet lag. And as any frequent flyer will tell you, jet lag can be hell.It's interesting to note that migrating animals, many of which trek tens of thousands of miles each year, are careful to stay within their time zones. Perhaps they intuitively know that crossing time zones can wreak havoc on their bodies, and the same is true for humans. If you've ever stayed up all night cramming for a final exam or completing a special project at work, you know how confused and disoriented you feel after even one sleepless night. The next day, you may have difficulty remembering things, feel hungry at inappropriate times, have difficulty regulating your body temperature, be short- tempered, and in general, feel off balance. If you don't sleep when your body expects to sleep, wake when your body expects to wake, and eat when your body expects to eat, you can throw all of your body systems out of kilter. This is precisely what happens in the case of jet lag. When we travel cross- country or across oceans to another continent, it can take several days for our bodies to adjust to the new schedule. In fact, the rule of thumb is that it takes the body a full twenty- four hours to recover for every time zone between New York and London, you will need an average five days to recover. Jet lag can be particularly hard on business people who need to arrive at their destination fresh and able to think clearly, and on vacationers who don't want to spend several days of their holiday feeling out of sorts.Since the 1980s, scientists have begun to take a serious look at the causes and possible treatments for jet lag. My colleague Josephine Arendt at the University of Surrey in Guildford, England, has pioneered many of these early studies. Dr Arendt was one of the first researchers to explore the use of melatonin as a means to prevent the symptoms of jet lag. Familiar with melatonin's role in regulating sleep/wake cycles, Dr. Arendt reasoned that melatonin should be able to reset the body's biological clock to help it adupt more quickly to a new time zone. After hundreds of experiments on human subjects, Dr. Arendt's research strongly suggests that people who take melatonin suffer far fewer symptoms of jet lag that those who don't and bounce back faster after long trips. Similar studies by other researchers confirm Dr. Arendt's results.Word spread rapidly of melatonin's positive effect on jet lag among frequent fliers. Publications for The Wall Street Journal to Vogue magazine to Business Week have focused on this particular use for melatonin, and today countless numbers of people use melatonin to prevent jet lag. I travel a great deal myself, and find that melatonin does the trick for me. I have been using it myself for twenty years.When you travel across time zones, take 3 mg to 5 mg of melatonin prior to bedtime once you are in your new destination. If you wake up in the middle of the night and are unable to fall back to sleep on your own, take another 3 mg to 5 mg to make yourself drowsy. Continue to take melatonin at night until you have full reset your body clock (which usually takes about four days). When you return home, readjust your body clock by taking 3 mg to 5 mg of melatonin before your normal bedtime. Most people find that by following this simple regimen they no longer experience the symptoms normally associated with crossing time zones. In addition to taking melatonin, here are some other simple things you can do to avoid jet lag:
  • Drink plenty of fluids while in the air to replace the fluid that are lost due to high altitude and changes in air pressure.
  • Avoid alcoholic beverages, as they can further disturb your already disrupted sleep cycles by interfering with your melatonin cycling.
  • Avoid coffee and caffeinated beverages such as colas, which can also interfere with sleep and contribute to dehydration.
  • Try to get enough exercise in your new destination. Often, when we're traveling, we don't walk or exercise as much as we do at home. The lack of activity can also contribute to sleepless night.
  • Take your meals at local time when you arrive at your destination. Digestion also helps the brain to accelerate its adaptation. 

spaziatore
torna in cima back top
spaziatore
spaziatore
spaziatore
spaziatore
Winter Depression

SAD is an acronym for seasonal affective disorder, a form of mood disorder that is triggered by the change of season, or perhaps more specifically, by the shortened days of fall and winter. Beginning from as early as September and lasting through March in the Northern Hemisphere. SAD victims are unable to adjust their body rhythms to the decreased exposure to daylight, becoming physiologically and ultimately emotionally, distressed and out of sync. Many experts now believe that the depressive symptoms associated with SAD are due to a shift in the circadian rhythm caused by a form of biological malfunctioning that occurs in response to the shorter and darker days of fall and winter. Since it is the pineal gland that is responsive to light, and its secretion of melatonin a key factor in the regulation of the circadian and related cycles, SAD research is now concentrating on the critical interplay among light, melatonin, and other fluctuating rhythms that regulate body chemicals.SAD strikes about 1% of the population, and is three times more likely to affect women than men. This comes as no surprise to us. Women's lives are more governed by biological cycles( such as the menstrual cycle) than are men's, and therefore are more likely to be vulnerable to the negative effects of a disruption in their biological rhythms. Although as far back as Hippocrates' time physicians have observed a seasonal change in mood, SAD was not officially recognized as a mood disorder until the early 1980s. Dr. Normal E. Rosenthal, a researcher with the National Institutes of Health, was the first to identify SAD and establish a link between a particular pattern of behavior and the onset of winter. According to the Diagnostic and Statistical Manual of Mental Disorders, the official guide to psychiatric disorders, there are some specific criteria for a seasonal pattern disorder.
  • There is a regular relationship between the onset of major depressive episodes and a particular time of the year.
  • The individual experiences a full remission or release from depression at a characteristic time of the year.
  • In the last two years, two major depressive episodes have occurred that demonstrate the relationship between the episode and the season, with no episodes having occurred outside of that time.
  • Seasonal major depressive episode outnumber the nonseasonal episodes over the individual's lifetime.

One of the most predominant features of SAD is a seasonal change in eating habits, usually seen as an increase in appetite that prompts a craving for carbohydrates. Typically, most of us do experience a change of diet during the colder months, eating more hot dishes, such as noodles or chili, and cutting back on salads and fruits because of the limited variety of available fresh produce. This doesn't sound particularly extreme. But for SAD patients, the dietary changes are more specifically related to mood. They report an increased intake of pasta, bread, pastry, potatoes, chips, chocolate and candy during the winter months. Their intake of caffeinated beverages also rises substantially. When asked why they chose these foods, hunger was never the driving force, but rather the selection was consciously made to combat tension, anxiety, or mental fatigue. After eating, in face, the majority of SAD sufferers reported feeling calm and clearheaded. There is a physiological basic for this. Carbohydrate- rich food appears to accelerate the production of serotonin, a neurotransmitter produced by the pineal gland that carries signals across the gaps between brain cells. Serotonin is also a precursor to melatonin, which means that it is converted to melatonin as the body needs it. Serotonin is believed to play an important role in alleviating some forms of depression and is the key mediator affected by Prozac, a popular and effective antidepressant.Along with carbohydrate cravings, there are a number of other key symptoms of SAD. Between 1981 and 1985, the National Institute of Mental Health surveyed over fifteen hundred patients with SAD and developed a statistical profile of the disorder. Among the findings:
  • 96% of SAD patients reported decreased activity in winter.
  • 946% stated that interpersonal problems- relationships with spouses, lovers, family members, fiends, and coworkers- occurred during these months.
  • 96% noted feeling of sadness, 84% experienced anxiety, and 79% reported increased irritability during the winter months.
  • Difficulties at work were mentioned by 88%
  • An increase in appetite and an overall change in body weight were noted. More than seven out of ten patients experienced an increase in weight.
  • More that six out of ten patients reported their sexual drive had dropped.
  • Some patients found that their symptoms of depression improved dramatically as they traveled closer to the equator, where the amount of night and day is equal.
While some symptoms of SAD are found in other forms of depression, the particular combination of lethargy, anxiety, irritability, and dietary changes matched up against the seasonal changes present a specific disorder.It is clear that SAD is caused by the disruption in the cycling of hormones and body chemicals that govern the circadian rhythm, to which the exposure to light is key. Exactly how or why this interruption occurs in some people and not in others is still under investigation.As we mentioned earlier, most of our bodily functions, including physical activity, sleep and food consummation, water intake, and body temperature operate on the circadian rhythm cycle. So, too, do the levels and cycling of crucial hormones and enzymes, which can profoundly affect mood. The control of these rhythms is in large measure a function of the timing and duration of our exposure to bright light. Researchers are now exploring the relationship between symptoms of depression as they are connected to fluctuations in body chemicals, and most particularly melatonin.

spaziatore
torna in cima back top
spaziatore
spaziatore
spaziatore
spaziatore
The Role Of Melatonin

Although the cause of SAD is not known, research so far suggests that SAD is triggered by a seasonal disruption in the cycling of melatonin, which throws the circadian rhythms off balance. In the majority of patients with SAD, melatonin does not fluctuate normally throughout the night. Under normal conditions, melatonin should peak at around 2 a.m. and then begin to fall. Studies have found that in SAD patients, however, melatonin levels remain high for about two hours longer than normal, and then begin to drop.It has been well documented that when melatonin levels are abnormal, either too high or too low, it can result in symptoms related to psychological disorder. For example, recent research has shown than melatonin levels are abnormally increased in people with manic disorder (subject to extreme mood swings), and yet are abnormally low in people with some kinds of depression. There is in fact a "low melatonin syndrome" in depression. The syndrome is characterized by low melatonin levels and disturbed circadian rhythms governing the production of stress hormones.Evidence does seem to suggest, however, that erratic secretion of melatonin is only one mechanism that produces the main symptoms of SAD. At this point it isn't clear whether melatonin is directly involved in causing SAD or whether abnormalities in melatonin secretion are simply a by- product or a marker of the illness. 
spaziatore
torna in cima back top
spaziatore
spaziatore
spaziatore
spaziatore
The Therapeutic Role Of Light

Researchers have learned that the farther north the area (in the Northern Hemisphere), the higher the incidence of SAD. In fact, latitude, the distance from the equator, is found to be the most important geographical element in determining the severity of the disorder. One recent study found that 25% of the population in northerly latitudes is affected by at least some of the SAD symptoms. This is especially true of weight gain and excessive daytime fatigue. Also, farther north,  where the darker days of winter begin earlier, SAD symptoms appear earlier and remit later in the year than they do in climates closer to the equator, where the seasonal light remains constant. In the northeast section of the United States, symptoms usually appear in late October or November and begin to remit in February or March. In contrast, the farther south toward the equator you go, the depressive episodes begin later and remit earlier.The issue of course with latitude has to do with the way sunlight strikes the earth. The farther north one travels the more diffuses the sunlight. The less sunlight the higher the rate of SAD becomes.A survey conducted by the newspaper USA Today revealed, not surprisingly, that states with higher northern latitude, a greater number of cloudy days, and generally lower temperatures reported the highest incidence of SAD. Some studies show that Northerners are ten times more likely than others to develop a case of SAD. Sharp changes in geography can even exercise significant influence over the triggering of SAD within very short periods of time. SAD patients report upon leaving a winter region and traveling to Florida that within days their mood lifts significantly.Upon returning to their home, they are plunged back into a depression within a matter of days.For people who are hypersensitive to changes in light, travel can disrupt the critical balance of their circadian cycles.The effect of light on mood has long been recognized by the medical profession but it wasn't until 1980, however, that light therapy became a recognized technique. Dr. Norman Rosenthal (the researcher who first identified SAD) was aware that melatonin produces seasonal changes the behavior of animals. He began to consider the possibility that melatonin might play a significant role both at the onset and in the severity of the disorder.Dr. Rosenthal explored what would happen if patients with SAD were exposed to bright light during depressive episodes. He found that the impact of light, both in terms of the speed and completeness with which it relieves SAD symptoms, was dramatic.A persuasive explanation for the profound decrease or elimination of SAD symptoms with exposure to light is that it helps to reset the biological clock that governs the secretion of melatonin. Research has also shown that for those SAD sufferers who have melatonin rhythms that for those SAD sufferers who have melatonin rhythms that are delayed as compared to normal patients, bright light advances the time of onset of melatonin secretion.Other researchers had similar results. Peter S. Mueller, a psychiatrist at the National Institute of Mental Health, reviewed in the early 1980s the emotional and geographical history of a twenty- nine- year- old woman he had been treating for cyclic bouts of winter depression. He noted that the farther north she traveled, the earlier the onset of depression and the longer she stayed depression into spring. That this was indeed a pattern was supported by the fact that when she journeyed to Jamaica during the winter months her depression disappeared within a couple of days of arrival. Mueller postulated that sunlight might be contributing in some way to the woman's depression and decided to experiment with light therapy. Light, he knew, has two effects on melatonin rhythms. It can reestablish the melatonin rhythm (day- time, through the use of light, can artificially be reversed with night) and it can suppress melatonin secretion entirely, (if periods are eliminated).On consecutive mornings he exposed the patient to 2,500 lux of supplemental full- spectrum light (1 lux is equal to the light emitted by one candle). The patient recovered from her depression within a few days. Through the use of light, Dr. Mueller had found a way to reset the woman's circadian cycle.Michael Termon of Columbia University has found that exposing SAD patients to 2,500 lux for two hours in the morning brings complete remission from both depression and carbohydrate craving in roughly half of SAD sufferers, and usually after only a few days of treatment. Dr. Termon also thought in may be possible to enhance the efficacy of treatment by increasing the amount of time patients are exposed to light or by increasing its intensity. Dr. Termon's group has recently developed a new computerized device that SAD patients can use at home that simulates natural light.Due to the large number of SAD sufferers, there are numerous centers springing up around the country that offer bright light therapy. For information on where to find a physician near you who specializes in the treatment of SAD, contact the psychiatric department of your local hospital of SAD, contact the psychiatric department of your local hospital or medical school.SAD and jet lag are examples of what happens when our naturally cycle are disturbed. When our bodies are working well, we are unaware of our circadian rhythms and the extent to which we are still under the influence of nature's biological clock. When our circadian cycles are disrupted, however, we feel the full force of nature's influence or our lives. We feel out of sync and out of touch with the rest of the world. It is then we most intensely feel the profound role that these natural cycles play our lives.
spaziatore
torna in cima back top
spaziatore

Disclaimer: The information presented herein strictly reflects the opinion of Prof. Walter Pierpaoli and is intended to provide information and for educational purposes. The information herein intends to support, and not replace, the existing relationship between a patient/visitor of this website and his/her referring physician and, in no case, can it be considered a diagnosis or used as an alternative to a medical examination. Prof. Pierpaoli undertakes no responsibility for any health consequences of any person who reads and follows the information contained on this site. All readers of the contents on this website, especially those who take prescription or over-the-counter drugs, should consult their physicians before beginning any nutritional or supplemental program or prior to making lifestyle changes. The contents herein are in compliance with the guidelines relevant to the application of arts. 55, 56 and 57 of the new Code of Medical Ethics and are intended for the general public.