sad is known as a kind of feeling, but here I meant something else. it's a kind of illness that I never thought I would suffer, until I spend the winter in Germany. anyway, more or less. just look around and you will not see green plants and the daylight is soooooooo few, to make me just want to isolate myself from the outside circumstance, it won't make me feel better, however it will also not make things worse. and here I just find the word "sad" could sooooo precisely describe the experience of SAD.

What is SAD?
SAD (Seasonal Affective Disorder) is a type of winter depression which affects millions of people every winter between September and April, in particular during December, January and February. SAD is caused by a biochemical imbalance in the hypothalamus due to the shortening of daylight hours and the lack of sunlight in winter. For many people SAD is a seriously disabling illness, preventing them from functioning normally without continuous medical treatment. For others, it is a milder condition, causing discomfort, referred to as sub-syndromal SAD or winter blues. There is also a rare reverse form of SAD, known as summer SAD, where symptoms occur each summer and remit in winter.
Symptoms
a desire to oversleep and difficulty staying awake, but in some cases, disturbed sleep and early morning wakening;
feeling fatigue and an inability to carry out normal routine;
a craving for carbohydrates and sweet foods, usually resulting in weight gain;
feelings of misery, guilt and loss of self-esteem, sometimes hopelessness and despair, sometimes apathy and loss of feelings;
an irritability and desire to avoid social contact;
a tension and inability to tolerate stress;
a decreased interest in sex and physical contact
and in some sufferers, extremes of mood and short periods of hypomania (overactivity) in spring and autumn.
SAD symptoms usually reoccur regularly each winter, starting between September and November and continuing until March or April; a diagnosis can be made after 2 or more consecutive winters of symptoms. In sub-syndromal SAD, symptoms such as tiredness, lethargy, sleep and eating problems occur, but depression and anxiety are absent or mild.

SAD symptoms disappear in spring, either suddenly with a few weeks of hypomania/hyperactivity, or gradually, depending on the intensity of sunlight in the spring/early summer. In summer SAD, symptoms may be related to excessive heat rather than light and may include irritability and lethargy rather than oversleeping and overeating.

SAD may begin at any age, but the main age of onset is 18-30. It occurs throughout the northern and southern hemispheres but is rare in those living within 30 degrees of the Equator, where daylight hours are long, constant and extremely bright.

Treatments
Light therapy has been proven effective in over 80% of diagnosed cases, with exposure from 30 minutes to several hours per day to very bright light, at least 10 times the intensity of ordinary domestic lighting. Ordinary light bulbs and fittings are not strong enough. Whereas the average home or office lighting deliver an intensity of 200-500 lux, the minimum dose necessary to treat SAD is 2500 lux. Some light units deliver up to 10,000 lux, which can shorten treatment time.
Light treatment should be used daily in winter, starting in early autumn when the first symptoms appear. It consists of sitting 2-3 feet away from a specially designed light box, wearing a Light Visor, or waking up to dawn simulator. Allow the light to shine on the eyes. While getting your light treatment carry out normal duties; eating, writing, reading, etc. It is not necessary to stare at the light during the session, but keep in mind that the more photons that reach the retina, the faster the session will be.
Treatment is usually effective within 3-4 days and the effect continues provided it is used every day. Sun glasses, tinted lenses, or any device which blocks the light to the Retina of the eye, should not be worn. Daily exposure to as much natural daylight as possible can be of help.

When it comes time to shop for a light unit, be a smart consumer and shop around. Weigh the pros and cons of the different products and different companies. Product economy is one factor, but product quality and company service are even more important. All reputable companies will offer a return system if the light doesn't work for you.

Traditional antidepressant drugs such as tricyclics are not usually helpful for SAD as they may exacerbate sleepiness and lethargy. The non-sedative SSRI drugs such as paroxetine (Seroxat), sertraline(Lustral) and fluoxetine (Prozac) are effective in helping the depressive symptoms of SAD and combine well with light therapy. Other psychotropic drugs (i.e. lithium, benzodiazepines) have not proven very useful in the treatment of SAD.

Psychotherapy, counseling or any similar therapy which helps the person with SAD to relax, accept their illness and cope with its limitations can be useful.

Who is NOSAD?
The National Organization for Seasonal Affective Disorder (NOSAD) is a small non-profit organization dedicated to helping people affected by SAD find support and treatment for their illness.
Links
The Society for Light Treatment and Biological Rhythms (research group) www.sltbr.org
The Circadian Lighting Association (manufacturers' trade association) have a code of practice to protect customer's interests on www.claorg.org
SAD was first described by Dr Norman Rosenthal working at The National Institute of Mental Health (he actually named the illness), his own site is on www.normanrosenthal.com

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