Light therapy
How light can help
Light therapy
Now we know that light influences our biological clock, our alertness and our hormone system, we can use light to decrease or even cure disturbance of the biological clock, alertness and hormone system. Light therapy is the general name for such treatments. It is clear that light therapy for the treatment of jetlag will differ from light therapy for the treatment alertness problems.
Light and winter depression
Mood problems during autumn, winter and early spring trouble many people every year. More than 1.2 million people in the Netherlands suffer more or less from these problems. Approximately 450.000 of them suffer from winter depression. It occurs in all layers of society; race, skin colour or social status play no role at all. Particularly women in the range of 13-55 years have a larger sensitivity to develop winter depression. Luckily an effective therapy has been developed that helps most people: light therapy.
Winter depression
The mood complaints during autumn, winter and early spring can be divided into classes of severity: winter depression (Seasonal Affective Disorder SAD) and the milder winter blues (Subsyndromal Seasonal Affective Disorder S-SAD). The treatment of winter depression has to be treated by a doctor.
Most common symptoms are:
- melancholy, low sprits, depression
- long sleep, sometimes more than 14 hours a day
- eating much, especially food with carbonhydrates
- gaining weight
- irritability
- tiredness
- withdrawing behaviour
The complaints have to occur for a minimum two consecutive years to call it winter depression. The symptoms mostly start during autumn, worsen in winter and disappear during spring.
Winter blues
The roughly 1 million people in the Netherlands with winter blues are (according the current criteria) not ill, but have complaints. The complaints are comparable to those of winter depression, but less serious. Symptoms like melancholy, low sprits or depression do often not occur in winter blues.
Causes of winter depression and winter blues
The cause of winter depression and winter blues is unknown. Because winter depression occurs when there is not much daylight and because the symptoms often decrease with light therapy, it is supposed that the disorder arises in reaction on the decrease of the amount of light in autumn and winter. Many studies are being performed to find the causes for this. Causes are looked for in the retina, in the biological clock, molecules, hormone system and the interactions between cells. For the time being some cause can be excluded. E.g. it is not very likely that the hormone melatonin plays a significant role: neither taking extra melatonin nor the withdrawal of self produced melatonin has a noticeable influence on the symptoms of winter depression. The research to find the influence of the biological clock on winter depression has not yet shown clear results. It is not sure that the biological clock is part of the causes of winter depression.
Light therapy
Although it is not known exactly why it is beneficial, it has been scientifically shown that light therapy is effectively diminishing the complaints of winter depression for many patients. Light therapy is a relatively new treatment within health care and home care. It concerns a course of cure in which bright light, without UV, is applied via the eye. The advantage of light therapy lies in the fact that the method is effective and easy to undergo for most people with winter depression and winter blues. It is not addictive and it is a very safe treatment. In general the doctor will prescribe a course of cure of 5 or 10 days light therapy, mostly during the morning. You have to sit during ½ to 2 hours (depending on the light intensity) in front of a light therapy device, in such a way that the light shines into your eyes. You can read, watch TV or work at the computer during the treatment, if only the light can reach you eyes. Your doctor can choose for a longer or shorter treatment or a larger or smaller distance to the device. This is dependent on the seriousness of the complaints, the sensitivity of the eyes and the use of medication.
Side effects
Light therapy has few side effects that occur seldom. Nevertheless it is useful to give them here. The most important side effects are:
- headache
- tired, dry or watery eyes
- redness of the face
- dizziness
In general the side effects disappear after a few days.
When not to use light therapy
Light therapy is a safe method. It is advisable to see an eye doctor before starting light therapy if one also uses medicines or has an eye illness. Medicines that cause an enhanced sensitivity of the eye are better not combined with light therapy. People with a manic-depressive disorder can only use light therapy if they are observed and supported very carefully because of the risk of getting a manic period. Ask always your doctor if you have questions.
More information
Light therapy is used in approximately 90 (psychiatric) clinics and RIAGG’s in the Netherlands. SOLG has the addresses. People with winter blues can buy a light therapy device for home use in a home care shop, a medical shop or pharmacy. It is advised to ask your family doctor before starting the treatment. If you have a winter depression diagnosed by a psychiatrist, after a first treatment in a clinic, after consideration with the doctor, you can also by a device. More and more medical insurance companies refund the costs of a device for home use in such cases.
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