You are feeling tired, you lost your appetite, you are more irritable and you wish you could hibernate all winter? Unfortunately, you’re not alone! In fact, 3% of the population will suffer from a type of depression that will reoccur every year with the onset of winter and that will disappear naturally in spring called seasonal depression, winter depression or seasonal affective disorder (SAD). At a milder level, 20% of the population will experience the same symptoms without being too bothered by them.
If you are pregnant or if you just gave birth, it is also possible to suffer from this seasonal syndrome. You know that using antidepressants could harm your foetus or your breastfed newborn but don’t throw in the towel because there is a solution that could certainly brighten your winter: light therapy!
A phenomenon that has long been known
Although for decades, even for centuries, we have known that light had an impact on our mood, it is only in the Eighties that light therapy became a field of scientific studies. Thanks to the first clinical study of light therapy and SAD led by Dr. Norman Rosenthal, hundreds of studies have also been able to demonstrate the benefits of phototherapy to treat seasonal depression.
In addition to being the best SAD treatment, other studies have also shown the benefits of light therapy on other issues such as post-partum depression2, PMS3, sleep disorders4, shift work sleep disorder (SWSD)5 and jetlag6.
In fact, light therapy seems to affect some brain chemicals called “neurotransmitters”, which increase energy, improve the mood and decrease appetite and the need for sleep. The biological mechanism of light therapy is not yet well understood by scientists.
Instructions – Where to find it
This treatment is relatively simple. Specifically, it only requires a morning exposure (ideally at the same time every day) to a controlled source of light for 20 to 30 minutes.
The lamp must emit a light intensity of 10,000 lux. By comparison, a well-lit office can emit 300 lux, a cloudy day is 2,000 lux and a beautiful and sunny summer day supplies around 100,000 lux. The clinically recognized standard is an exposure to 10,000 lux, at eye level, at a distance of about 50 centimeters for 30 minutes 7,8.
In addition to high light intensity, the light therapy lamps emit a specific spectrum and are equipped with an ultraviolet (UV) filter so you don’t have to worry about getting a tan. It is also important to know that the therapeutic effect of the light goes through the eyes, not the skin. Therefore, unlike when bronzing, it is essential to keep your eyes open in phototherapy. Even if it is not necessary, it is not harmful to stare at the fluorescent tubes. However, I suggest doing something more stimulating during your treatment like reading, eating breakfast, watching television, reading emails or simply relaxing as long as you are 50 centimeters away from the lamp. Don’t forget that your face must be bathing in the light and your eyes must remain open. After one to two weeks of regular use, you will notice an increase in your energy and well-being, just like 80% of the other users9.
The results did not show any ocular changes after short, middle or long-term phototherapy treatment10.
The side-effects of light therapy are rare and mild, especially when compared with the use of antidepressants but some people may experience headaches, insomnia, dry eyes, restlessness and nausea11-13. If it happens to you, decrease the duration of your treatment and gradually increase it again to reach the recommended time of 30 minutes.
In terms on cons-indication to the use of light therapy, experts agree that people who suffer from retinitis pigmentosa, glaucoma, cataracts and other diseases affecting the retina (e.g. diabetes) should avoid light therapy 14,15. People who are using medications that induce photosensitivity, such as lithium16, should not consider using phototherapy either.