From "In Touch Zhejiang" magazine, December 2005/January 2006

Chronobiology: not a Swiss watch

Winter is fast on its way, with the days getting colder and the nights getting longer. Christmas and New Year will soon be upon us and it’ll be time again to make merry with family and friends. ‘Tis the season to be jolly. Right?
Well, that’s what they say. But many people suffer from depression this time of year. Partly it’s social- feeling lonely while others are celebrating with family and friends, and of course, many foreigners living here in China will be missing their families. But there’s a physical component as well- SAD.
Seasonal Affective Disorder, SAD, is a form of depression that occurs primarily during winter months as a result of the shorter days and subsequent decreased sun exposure wreaking havoc on the body’s circadian rhythm. What is going on here and is there anything to be done about it?
The human body, like plants and most other life on Earth, is affected by the cycles of light and dark that comprise Earth’s 24-hour day. These biological effects are called circadian rhythms (circa, about + die, day) and play a vital role in virtually all life on Earth. In humans, bright light (until recently only found during daytime hours) causes a tiny gland in the base of the brain, the pineal, to turn off, while darkness turns it on. Thus, in the evening, when it gets dark, the pineal switches on and begins to produce melatonin out of the melatonin precursor serotonin. Melatonin levels then increase and serotonin levels decrease (because serotonin is being turned into melatonin). Melatonin causes one to feel sleepy and shuts down certain metabolic processes, notably those of the digestive and reproductive systems, so the body can carry out its rejuvenatory functions during sleep. In the morning, bright light from the sun shuts the pineal off, melatonin levels decrease, serotonin levels increase (it’s no longer being made into melatonin) and we feel vibrant and awake. This is the physiological basis of the circadian rhythm in humans.
Winter’s shorter days mean less sunlight and this means the pineal gland is on more of the time, making melatonin out of serotonin. This in turn leads to decreased serotonin levels- the suspected cause of SAD. Of course, the further from the equator the shorter the days, which explains why SAD occurrence increases with distance from the equator. So what can you do to keep your biological clock ticking properly?
The first thing, and for some of you this will be worse than when I suggested not eating ice cream, is go to sleep early and get up early. This is the way humans evolved and there’s no getting away from it- it’s built in to our physiology and going against it disturbs the all-important circadian rhythm. It’s no coincidence that all over the world you will find the equivalent of the saying, “Early to bed, early to rise, makes a man healthy, wealthy and wise.” Staying up late deprives the body of the best sleeping hours in the night, and so another saying goes, “An hour of sleep before midnight is worth two after.”
Furthermore, staying up late almost always means sleeping in late. This denies the body the opportunity to fully shutdown pineal production of melatonin during the day, which is achieved most effectively by exposure to bright morning light. Thus melatonin levels are higher and serotonin levels lower than they should be during the day, leading to depression, fatigue, loss of appetite, and decreased reproductive function and libido (more on that next month). Regardless if one suffers from depression or not, it’s always best to maintain this sort of sleeping schedule. However, when truly suffering depression a healthy sleep schedule is critical if a natural approach to recovery is desired.
Ideally, one should be in bed by 9pm, but before 10pm is acceptable. Wake around 5-7am and immediately open all the curtains in the house to let the light in. Then expose yourself, to the light that is, sunning your face (close your eyes and face the sun) for a few minutes. If there’s insufficient natural light one can use artificial light to achieve the same effect.
Secondly, eat a diet rich in tryptophan. Tryptophan, one of the “essential” amino acids, is a precursor of serotonin, so a deficiency in the diet will lead to decreased serotonin. Some examples of tryptophan-rich foods are: seaweed, soy products (tofu, soy milk, etc.), bananas, dates, figs, peanuts, almonds, pecans, sesame seeds, legumes, fish, meat and dairy products. Note, tryptophan is better absorbed in the brain when consumed as part of a high carbohydrate meal, so super-size some fries with your order.
Thirdly, get sufficient exercise. Exercise is crucial to maintain good health and has been shown to help with depression. Do whatever you enjoy- working out in a gym, hiking, biking, swimming, yoga, martial arts, etc. Yoga and martial arts are particularly recommended as they include “internal” practices that help regulate and harmonize the
physiology.
Finally, if lifestyle and dietary changes are not enough, a visit to the doctor may be in order. Chinese medicine quite effectively treats depression, regardless of the cause, but for severe cases it may be necessary to integrate with western medicine (the psychiatric pharmaceuticals are strong and fast acting) and psychological counseling. In those cases, continued use of Chinese medicine can help reduce the need for and alleviate the side effects of the pharmaceuticals and speed up the overall recovery. In more moderate cases, Chinese medicine alone may suffice.
Acupuncture, the effects of which can often be felt immediately with many patients reporting a marked sense of wellbeing after treatment, helps regulate the circadian rhythm, calms the mind, elevates mood and also treats many of the accompanying symptoms of depression such as fatigue, loss of appetite, insomnia, etc. Chinese herbs are typically prescribed in addition to acupuncture or as the sole form of treatment in cases where the patient doesn’t want acupuncture. Diet and lifestyle counseling are important components and each patient receives advice tailored to their particular condition.
In all cases, whatever modality of Chinese medicine is used, treatment is tailored to the individual’s condition and does more than just treat the depression. CM views the body as an organic whole, so treatment is not aimed at symptoms per se, but at harmonizing the body’s physiology in general. This in turn leads to reduction of most or all of a patient’s various symptoms, seemingly related or not, and not just relief from the chief complaint (depression, in this case) for which the patient came to the clinic seeking treatment. Side effects are few, if any, and virtually never as severe as those from psychiatric meds.
Everyone can benefit from following the above lifestyle recommendations, and with that alone some will stave off any effects of SAD they may have otherwise incurred. But if you or someone you know is suffering from a bout of winter-blues, or a more severe form of depression, it’s worth considering consultation with a Chinese medicine physician. Here’s wishing you all a cheerful holiday and a happy new year!

Copyright© 2005 Greg A. Livingston