The light at the end of the winter tunnel

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.

Side-effects

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 nausea^11-13. 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.

Where can I buy a lamp?

Most pharmacies, department stores and orthopaedic suppliers sell phototherapy lamps. It is important to choose a lamp according to certain criteria:

• It must emit 10,000 lux in light intensity;
• It must have a UV filter (which is in fact a hard plastic membrane);
• It must emit a large ray of light to remain effective if you move (beware of portable lamps that you can hold in your hands);

White light is recommended because it is harmless, unlike the blue light (you should avoid the lamps that use light-emitting diodes because certain studies have shown that they could harm the retina^15,17-19).

You can expect to pay around $200 for a safe phototherapy lamp. However, in the past few years, some insurances companies have begun covering some fees when you have a doctor prescription. In the long run, it was demonstrated that this method is cheaper than antidepressants.

What about the kids?

It is proven that children and teenagers can also suffer from SAD and phototherapy can be beneficial to them²⁰. Similarly, in adolescence the internal rhythms of waking and sleeping are shifted. As you probably noticed, getting up requires huge amounts of energy and they prefer to liv by night. This discrepancy can be explained by a later production of melatonin, a neurotransmitter, secreted at night by a part of our brain, the pituitary gland. It is the melatonin that brings the first signs of tiredness after the evening news, for example. It has been proven that being exposed to an intense light suppresses the production of melatonin ²¹. Thus, to regulate the secretion of melatonin, phototherapy can be used and helps to improve the quality of sleep and reduce the irritability of our teens.

There also is a new device, the dawn simulator that reproduces the sunrise in our bedroom. It is an alarm clock equipped with a lamp that gradually lights up 30 minutes before the time you want to wake up. That way, you can wake up naturally and gently. The results are encouraging for the moment and show that the quality of sleep would be improved in some people²². This device seems to help parents get children and teenagers out of bed more easily, when it was a problem. For people affected by SAD, its effectiveness is possible but studies are rare compared with the main treatment: phototherapy.

Other strategies

Because light therapy is not effective for all users and because its effectiveness can be limited for some, there are other alternative treatments that can help you cure your seasonal syndrome.

Thus, even if light therapy leaves you with a feeling of remaining fatigue and distress, don’t hesitate to first consult your doctor. It is also possible to consult a psychologist to help you through this. Remember that there are many approaches and schools of thought in psychology. The approach that I suggest is the cognitive-behavioural treatment that focuses on changing thoughts and inappropriate behaviours. It is a practical technique that has proven effective for treating anxiety and mood disorders, among others^23,24. So you don’t risk being in therapy for ten years!

You can visit the Ordre des Psychologues du Québec to take a look at the different approaches and find psychologists in your area.

Physical activity is another strategy to try since it has been proven that it could reduce depressive and anxious symptoms²⁵. Enjoy the beautiful winter days and choose a sport that you will enjoy alone, with your family or with your friends. You will feel energized!

Finally, there is medication. Even if it is the last resort to treat SAD, medication can be justified for a short period. Lately, the U.S. Food and Drug Administration mentioned that Bupropion (Wellbutrin) is the best antidepressant to treat SAD symptoms²⁶. Ask your doctor.

Thus, light therapy is a natural treatment that has proven its effectiveness for over 20 years to treat SAD. So, brighten your winter!

Inspiring readings

• (IN FRENCH) Du soleil plein la tête : Démystifier le trouble affectif saisonnier et ses traitements. Marie-Pier Lavoie en collaboration avec Gérard Pons. Éditions Quebecor. 2009
• "Winter Blues - Everything You need to Know to Beat Seasonal Affective Disorder" by Dr Norman Rosenthal
• (IN FRENCH) Information about SAD and its treatments
• Light therapy products
• Ordre des Psychologues du Québec : to find out more about the different approaches and to find a psychologist near you