By Ileiren Byles
Staff Writer

One could be forgiven for not noticing the days getting longer.  While Dec. 21 marked the shortest day of the year and the gradual procession towards more daylight, St. Albert residents can still only glimpse the sun for about seven hours a day - less if they're stuck in an office for the majority of daylight hours. That dearth of natural sunlight has more of an effect on our bodies and state of mind than we realize.

Beyond the winter blues, the more severe Seasonal Affective Disorder (SAD) is thought to affect almost five per cent of the population, said Robin Harris.

"It's a common thing. Our bodies were really designed to use light as a clue for its sleep cycles," said the spokesperson for Litebook, a Medicine Hat company that produces hand-held devices to combat SAD. "The last stats said 25 per cent of the North American population suffers from winter blues and five per cent from SAD. A lot of us just feel blah in the winter, but more and more doctors are actually prescribing light therapy for more extreme cases."

According to the Mood Disorder Society of Canada, studies report women are eight times more likely to suffer from SAD. Seasonal depression often first appears when people are in their 20s and 30s and the prevalence of SAD increases until the mid-50s, when the rates begins to decline.

The symptoms of SAD do differ from clinical depression and include:

• Low mood, reduced interest in normally pleasurable activities, decreased concentration;
• Oversleeping (often an increase of four hours or more each day);
• Low energy and fatigue;
• Intense craving for carbohydrates;
• Weight gain and carbohydrate/sweets craving;
• Withdrawal from social contacts;
• Depression.

Although no one's nailed down for sure what causes SAD, many researchers believe it may have to do with a function of sunlight that switches off the production of a hormone called melatonin. 

"Melatonin is what your body produces to help you sleep," said Harris.

"Usually, a good dose of light in the morning will stop your body from producing it. But if you're getting to work before there's any light in the sky, it's possible you'll keep producing melatonin throughout the day and that's going to leave you sleepy and listless. The other thing the light does is stimulate the production of serotonin, the body's natural feel-good hormone."

The fluorescent lights that grace most offices just aren't sufficient to stimulate the hormonal balance in some people, said Harris.

"It's a hard thing for a lot of people to intellectually understand," she said. "Even though it seems like the light in your office is so bright, it's not strong enough. It's still like 100 times less than what you need."

The Litebook and other products like it emit a wavelength of light optimal for melatonin suppression - without harmful UV rays.

"The best time to use it is first thing in the morning. You want to shut off that melatonin and that will give you a lift throughout the day,"
said Harris. "And some people also believe it makes you more sensitive to the melatonin at night, so you sleep better."

Although some doctors have been prescribing light therapy for SAD cases, a lot of people are buying the $259 devices just to boost their mood through winter, said Harris.

"People are just looking for ways to feel better," she said. "It's just something that gets incorporated into their day, like taking vitamins or drinking enough water."

ibyles@stalbert.greatwest.ca