If you find your mood being affected by winter’s shortening days, there is no reason to remain in the dark any longer. The truth is you’re not alone.
About 15 per cent of the population notice feeling worse during the winter compared to summertime, and about one per cent of the Canadian population suffers from Seasonal Affective Disorder (SAD), a type of depression where people are depressed during the wintertime but well during the summer.
“We don’t know any of the causes for depression,” said Dr. Raymond Lam, a UBC professor and psychiatrist at the Djavad Mowafaghian Centre for Brain Health.
But there are two theories for what causes SAD in particular. The main theory is related to the disturbance of the biological clock. Shorter days create a “sort of jet lag where your internal clock is out of sync with the external environment,” said Lam.
Exposure to bright light, he said, is the strongest synchronizer of the internal clock. The effect of this exposure is regulated through the eyes — light travels from the retina, the back of the eye, to the biological clock in your brain. Basically, if it’s summertime, your eyes know about it.
The second theory has to do with the fact that light exposure increases production of chemicals in your brain thought to be disturbed in depression, like serotonin, dopamine and noradrenaline. Lam insisted, however, that these theories are not necessarily mutually exclusive. The causes may be a combination of both.
Research conducted by Lam has shown that exposure to bright light can effectively treat both SAD and the “Winter Blahs,” a term used for less severe seasonal mood fluctuations. The light, however, must be at least 10 times as bright as the brightest office lighting, according to Lam. So turning your bedside lamp on won’t quite do the trick.
Instead, Lam and other scientists recommend Light Box Therapy, in which individuals are exposed to 5,000 to 10,000 lux (the unit used to measure illumination) of light from a special lamp for 30 minutes every day. To give you an idea of what that exactly means, a typical overcast Vancouver day emits 1,000 to 2,000 lux, and the brightest sunlight emits up to 120,000.
This is a well-established treatment that has been used for over 30 years, said Lam. The best time to do it is right when you wake up and before it becomes light outside (in theory, those are supposed to happen at the same time). You don’t have to be looking directly at the lamp, he said — you can be eating, reading, even on your computer or tablet. You just have to be awake because your eyes have to be open for the light to have the proper effect.
Lam cautioned that it is important to self-screen and consult your family doctor if you think you are experiencing symptoms of SAD, some of which include oversleeping, overeating, carbohydrate craving, weight gain, problems with fatigue and loss of energy during wintertime. Additionally, those with retinal diseases and bipolar disorder should talk to their doctor before using a light therapy lamp. If your symptoms are more along the lines of Winter Blahs, however, Lam said it’s “okay to try out the lights on your own.”
As the hours of daylight decrease and the hours of studying increase, it is important to monitor factors that can affect your mood and how they can be treated. Keep your eyes open. Some light might get in.
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