And for some, the sojourn into darkness means a journey into the throes of Seasonal Affective Disorder, a form of depression believed to be caused by a lack of sunlight.

"It seems like every winter I sleep more and more, and the blahs get worse and worse," said Juneau resident Shelly Wintergren while shopping with her cousin, Anne Parmentier, at Fred Meyer.

"It's bad enough down where I'm from," said Parmentier, who was visiting her cousin from Portland, Ore. "I don't know how Juneau people do it."

Do it, we must. For as inhabitants of an overcast rain forest above 58 degrees latitude, we live in one of the darkest places in the country.

Dr. Robert Schults, a Juneau psychiatrist, has heard anecdotal claims that SAD is more prevalent in Juneau than Anchorage due to our town's "varying amount of daylight."

"I see it beginning in August, when there's that shift in the sunlight," Schults said.

When it's dark outside, some Juneau residents become more sedentary and speak of "cabin fever." Everyone is different when it comes to surviving the winter. And many start to crave light - any light.

Light boxes, with a row of bulbs that produce a range of 10,000 lux, are thought to be an effective way to combat SAD, according to the National Institutes of Health. The 10,000 lux field is bright enough to stimulate the eye's photoreceptors, produce serotonin in the brain and decrease our amount of melatonin, a hormone that causes us to sleep.

A few years ago, there was a lot of publicity about so-called "full-spectrum" lights. But data has shown their importance may be over-hyped.

"I have seen a lot of evidence that you don't need the full spectrum," Schults said.

A decent 10,000 lux light box will cost you roughly $250 and up. You can find them at South East Alaska Medical Suppliers at 5636 Glacier Highway, or online.

SEAMS sells about six to eight light boxes a year, employee Wilber Sangster said.

"That's not too bad," he said. "Places where there's more darkness than we get here - they're definitely going to need these particular lights."

The store offers two models: One that's about 12 to 14 inches tall and comes with a timer, and another that's a wider floor box.

"They're pretty spendy, but they do the job," Sangster said.

"It's not the size, but how it works for you," he said. "You get a small one; you're just a little closer. Get a medium-size one; you can be further out. A bigger one, and you can be much further out."

Most doctors recommend standing 18 to 24 inches away from the light for 30 to 60 minutes a day, Schults said.

"A lot of people say, 'How am I going to build enough time in my day for using the lights?'" he said. "It's helpful if they can do it while they're doing their chores or things like that during their home routine.

"If they spend too much time in front of the light, they can have trouble with sleep," he said. "And actually, it's not too uncommon that people who have the winter blues get a little too excited come June and do risky things that they might later regret."

At the University of Alaska Southeast, SAD is a common enough problem that the disorder has its own page in the student housing handbook (www.uas.alaska.edu/housing).

The UAS Student Resource Center has six lights that it loans out to students. There's also a light set up at the university library and another inside the student housing lodge.

"They are effective," said Colleen Stansbury, a physician's assistant at UAS. "The problem is that the lights are more effective if you use them consistently ... Really, one should start in September. But we start people at any time."

Stansbury said most students from up north are pretty aware of SAD.

"They're aware of exercising more and even if there's just an hour of bright light during the day you get out in it," she said.

It's the students from Down South, places such as California and Arizona, who are caught off guard, Stansbury said. Suddenly it's December, they can't get out of bed, they've lost their drive and they've gained 10 pounds.

"These are students that don't have any prior history of depression, and they are affected by the light," Stansbury said. "It takes several months."

Stansbury doesn't suffer from depression, but she started to feel "light deprived" during Juneau's gloomy summer of 2006. She contemplated building her own light box, heading into the fall.

"They're essentially a fluorescent light ballast, but the lights are expensive," she said. "It probably costs about the same if you make your own, as opposed to buying one."

Stansbury settled on ordering one online. It hangs in her office above her desk. When she does paperwork in the morning, it shines down on her.

"I feel like a little plant under my grow light," she said. "And it's the same theory. We are creatures of light."

Korry Keeker / Juneau Empire   Seeing the light: Wilber Sangster, an employee at South East Alaska Medical Supplies, displays one of the store's SAD lights.

Seasonal Affective Disorder is a form of depression that was first diagnosed in 1984 by Dr. Norman Rosenthal. The disorder is thought to be caused by the lack of sun in the autumn and winter.

The National Institutes of Health estimates that approximately 37 million Americans experience some sort of prolonged gloominess or depression during the dark winter months.

A 1990 psychiatry report, "Prevalence of Seasonal Affective Disorder at Four Latitudes," claims that 8.9 percent of Alaskans suffer from SAD, and 24.9 percent experience a mild form that's not severe enough for a formal diagnosis.

Statistically, depression is a difficult disorder to quantify. There's no virus that shows up in a lab sample. And some people's SAD may be another's "winter blahs."

For those reasons, the Division of Public Health in the Department of Health and Social Services does not have statistics on the number of Alaskans with SAD.

"There are a number of diseases that are reportable by health care providers and laboratories," said Donna Fearey, a nurse with the Division of Public Health and Epidemiology. "But Seasonal Affective Disorder is not one that we have any handle on."

• Korry Keeker can be reached at 523-2268 or korry.keeker@juneauempire.com.