Light therapy: what is it? | JDM

Gray weather, loss of sunshine and lack of energy: while many Quebecers are starting to feel the effects of seasonal depression, some experts recommend turning to light therapy to combat gloom.

Seasonal depression, or seasonal affective disorder (SAD), affects around 20% of the population to varying degrees, according to data from Quebec’s chief scientist.

Here’s everything you need to know about light therapy, a natural way to combat the symptoms of seasonal depression.

What is light therapy?

A very first study carried out by an American psychiatrist in 1984 established a direct link between lack of light and depression.

Indeed, brightness would have an impact on the human biological clock, as well as on the production of certain hormones, including melatonin and serotonin, which respectively regulate sleep and mood, we can read on the scientist’s website in chief of Quebec.

Thus, light therapy is a form of therapy during which the patient is exposed to an intense light source, designed to reproduce the effect of the sun, in order to stimulate the production of these hormones and regulate the circadian cycle.

The effectiveness rate of light therapy would be similar to that of antidepressants, we can read, while it would improve mood in 60% of patients, according to psychologist Marie-Pier Lavoie, specializing in SAD.

The advantage of this therapy is that it has proven effective in many patients without requiring the use of medications, such as antidepressants.

What type of light should I use for light therapy?

It is recommended to use white light of 10,000 lux, avoiding bluish LED-type lights which can damage the retina in the long term, continued the psychologist, cited by the chief scientist.

A lux is a unit that measures the amount of light produced by an object over an area of ​​one square meter. The higher the luminous flux, the more light the surface will receive.

When should you start light therapy?

Ideally, light therapy should be started even before symptoms appear, either at the end of August or mid-September, or even at the end of the summer vacation, Marie-Pier Lavoie told the Journal last year.

Light therapy sessions should preferably be held as early as possible in the morning, for example while having lunch or upon arriving at the office, and continue until spring, with the aim of the daylight saving time change, which will be held in the night of March 8 to 9, 2025.

Some lamps also have a gradual wake-up option, which copies the effects of a sunrise to help regulate your circadian rhythm.

How long per light therapy session?

With a light of 10,000 lux, it is recommended to hold sessions of 30 minutes per day to feel the benefits of light therapy.

On the other hand, if the lamp you have is less powerful, for example 5000 lux, you would have to expose yourself longer, for 60 minutes, to obtain the same results, according to the chief scientist of Quebec.

As an indicator, the intensity of light on a cloudy day is around 2000 lux, while that on a sunny day, 100,000 lux.

In spring, when natural light returns to the horizon, it is advisable to gradually reduce your sessions from 30 to 15 minutes, or to use it only every other day, to ensure that morale holds up before to stop using it.

How far should you place your light therapy lamp?

The lamp should be positioned between 40 and 50 centimeters from the face, making sure not to look directly at the lamp so as not to damage your eyes.

The latter can be placed on the table in the room during breakfast, on the desk next to your computer during work or near an exercise machine, such as a treadmill or stationary bike, during a morning sports session.

Keep your eyes open or close them?

To achieve the desired effect, it is not the face itself that must receive the light, but rather the retina, so it is essential to keep the eyes open during light therapy sessions – making sure once do not look at the lamp directly.

How long before you feel the effects?

One to two weeks is generally sufficient to establish whether light therapy is working for the patient, according to the psychologist.

On the other hand, if the encouraging results are felt quickly, the same goes for the symptoms of seasonal depression, which can come back full force after just a few days without using the lamp.

However, light therapy should not replace a healthy diet and physical activity: two other elements that greatly help combat seasonal depression.

Are there any harmful effects of light therapy?

If overdone, light therapy can cause symptoms similar to coffee use, either agitation or insomnia, the psychologist told the Journal.

In certain rare cases, it can also cause some side effects, such as headaches, nausea or irritability, but these inconveniences would be short-lived, according to Quebec’s chief scientist.

Those suffering from eye problems should also consult a healthcare professional before attempting this therapy, according to Brunet’s website.

Is working facing the window enough?

Sitting in front of your window to take a bath in natural light is not enough to recreate the effect of a light therapy lamp on the body, estimated Marie-Pier Lavoie.

According to him, a well-lit room would diffuse around 200 lux, while a lamp designed for this purpose generally reaches 10,000 lux.