How Light Therapy Helps Minnesotans Over Winter

MINNEAPOLIS (WCCO) -- As Minnesota makes its way through the darkest part of the year, people who endure it have to get creative with ways to fight the fatigue often associated with seasonal affective disorder.

Some take vitamin D supplements, some get light therapy boxes, some do both.

Vitamin D supplements can help a person's body when it lacks direct exposure to sunlight.

Therapy lamps can help that person's mind. Research from the Mayo Clinic suggests the light boxes work in its attempt to adjust its users' circadian rhythm.

The reason why, according to Dr. Craig Sawchuk, goes back to how seasonal affective disorder is defined. He says despite its acronym, it doesn't necessarily make people feel sad, rather, they tend to feel unmotivated.

"So it's more of a flattening of their aspect," Sawchuk, with the Mayo Clinic, said. "They tend to oversleep, get a lot of carbohydrate cravings, and a lot of withdrawal, too."

He says darkness tends to bring melatonin levels up, which makes people sleepier, and brings serotonin down. Serotonin keeps the mood in check, among other things.

"So this is the idea, that once it's exposed to bright light, that helps the melatonin get settled back down again, and hopefully that helps to charge up production of serotonin as well," Sawchuk said.

He says the key is to use the light within an hour of waking up for 20-30 minutes. Sawchuk recommends light boxes of 10,000 lux or brighter, as those are the most efficient. Less bright lamps will still work, but he says they will generally take longer to give the full effects.