Everyone sees it, when the good weather arrives, morale picks up again, while with a winter that drags on a little or seems longer due to the Covid-19 pandemic, many people experience blues. qualified by specialists as seasonal affective disorder syndrome (SAD for Seasonal Affective Disorder ). In addition to the worries of daily life, the lack of solar luminosity comes on top and mainly affects the moral well-being of the elderly, the sick and women. Light therapy can help deal with this seasonal depression, respecting a specific framework.
Without sunlight, light therapy is based on the use of a lamp reproducing the natural light of the star, in front of which the person is exposed. No question of taking your desk lamp or a powerful garden spotlight, even if their led bulbs give off a white light, the closest to natural daylight.
The major difference with daylight lies in the light spectrum, which does not contain ultraviolet rays, which are well known to be harmful to the skin and eyes. The illuminance is expressed in lux:for example, outdoors, when the sun is at its zenith in summer, it will be 120,000 lux while a cloudy to very cloudy sky can cause it to drop below 10,000 lux. . As in addition, the days are short in winter and we live more indoors, exposure to bright sunlight is insufficient and our internal balance suffers. The most frequent manifestations are found in fatigue, lack of tone, weakness, sadness, gloom.
The scientific team of the American psychiatrist, Dr. Norman E. Rosenthal, defined SAD in 1984 by providing light therapy as a remedy. Years passed and research deepened until in 2006, light therapy was officially recognized by the American Psychological Association as an effective first-line treatment for seasonal depression and certain sleep disorders.
In September 2019, French researchers from Bichat-Beaujon Hospital in Paris and Strasbourg University Hospital published a study in Sleep Medicine Reviews , showing that light therapy brought a very clear benefit in people with seasonal depression which could be of the same level as antidepressants, even adding that the combination of the two treatments would increase the effectiveness which would be observed more quickly.
Since light therapy replaces sunlight, it will play on our biological rhythms, on our secretions of melatonin, often called the sleep hormone because it is the great organizer of our chronobiological rhythms, and on our level of serotonin, neurotransmitter, known as the happiness hormone.
In addition to seasonal depression, the effectiveness of light therapy is also verified on standard or chronic depression.
Regarding the depression surrounding childbirth (before and after), light therapy can only improve the mood and morale of the mother, who is reluctant to take antidepressants which would act on the baby, especially if she breastfeeds afterwards.
By regulating the biological clock more favorably, states of chronic fatigue will thus be improved thanks to light therapy, which will also remedy sleep disorders and insomnia, very common in seniors who often tend to fall asleep early and wake up. early or have a choppy sleep.
A person with Alzheimer's disease who would have recourse to light therapy at the beginning of the disease, could thus delay the degeneration of the cells which give rhythm to the biological clock.
Apathy, lack of concentration, eating disorders or annoyance caused by jet lag can be improved by light therapy. It's worth a try if it helps not to increase or even decrease antidepressants. In addition, dependent elderly people who rarely go outside may find this technique a way to maintain a better sleep-wake balance and a more positive mood!
Daily exposure to a maximum of 30cm from a 10,000 lux light therapy lamp, for 30 minutes in the morning, for example after taking a shower and drinking coffee, can be recommended from September to April. If your lamp diffuses 5000 lux, you will need to expose yourself for 1 hour for the same contribution. You can continue your activities during the exposure, as long as your face receives good lighting:reading, breakfast, television, office work...
In general, the benefits are felt within a month. Temporary side effects may appear (visual fatigue, headaches, nausea) which are often a sign that the acclimatization period was too rapid.
Be careful, some diseases such as AMD are not compatible with light therapy:it is better to ask your doctor for advice beforehand.
Specialists advise choosing a lamp with a white light intensity of 10,000 lux including UVA and UVB filtration. The cost varies from 70€ to more than 200€ depending on the ergonomic characteristics, size, intensity adjustment, etc. Make sure it has European CE medical device certification (93/42/EEC) and is easy to handle and use.
