For years, Sarah Browne couldn't figure out why, when winter started, she'd "turn into a slug."

Living in Wisconsin at the time, Browne said the cold temperatures, heavy snow and fewer hours of sunlight would prevent her from leaving the house.

"I couldn't get out of bed, I wouldn't want to talk to anyone, I'd have crying spells. It was like my brain was wrapped in cotton batting," says Browne.

But then when the sun returned for a few days, or in the spring, Browne says she returned to her cheerful self. At first Browne attributed her malaise to the hassles of being a working mom and living amidst lots of snow, but her therapist started seeing a pattern.

"She remembered an uncharacteristically spring-like day a few days before and asked how I'd felt on that day. It had been an awesome day for me," Browne says. "She kept running through days that were sunny; it was really a process of elimination."

The 40-something media consultant was diagnosed by her doctor with seasonal affective disorder, a form of depression that goes well beyond just the "winter blues." The symptoms and effects are similar to depression but only reveal themselves in the fall and winter months.

"You'll start slowing down, have difficulty waking up, difficulty concentrating, you'll start craving sweets and starches," says psychiatrist and SAD expert Dr. Norman Rosenthal, author of "Winter Blues," one of the first books to describe seasonal affective disorder.

"You'll notice I didn't mention depression," adds Rosenthal. "The mood thing is quite a late development in the sequence, so it's important for people to keep an eye out for these early signs so it doesn't develop into depression."

According to Mental Health America, women suffer from SAD three times more often than men, as do those in colder climates and people who work for extended periods without sunlight or work the night shift.

Sometimes just a change of scenery can work wonders.

Browne, who has since moved to the much sunnier Carmel Valley, Calif., recalls a work flight she used to regularly take from Chicago to Phoenix. "When I'd get off the plane I would transfer into a different human being to the point that people would actually notice and comment."

Treating SAD often combines a routine of light therapy, exercise and Vitamin D; more severe sufferers may be prescribed an antidepressant. But there are many natural remedies that can help alleviate SAD -whether you suffer from the condition or are experiencing general winter blues.

The number 1 therapy most doctors recommend for SAD is exposure to sunlight or full-spectrum light (which simulates bright sunlight).

"Ideally, even in the cold, you should try to find a way to get outside -even if it's snowshoeing," says Dr. Mark Hyman, author of "The Ultramind Solution," who has treated patients for SAD in his New York practice. Visiting a brightly lit garden store or a public atrium filed with light and live greenery can help as well.

Another way to simulate the sun's benefits is to take a regular dose of Vitamin D. Mary Sahs, a 62-year-old Michigan-based Naturopath, says she has suffered SAD for 30 years.

"This is my first winter to try a vitamin D supplement and it made a significant difference in my mood," says Sahs.

"To me exercise is the salvation," says Browne, "But I need to exercise to the point of sweating."

A study by the British Journal of Sports Medicine found that just 20 minutes of sustained, vigorous exercise a week can help reduce depression. Walking around the block, scrubbing the kitchen, dancing to your favourite songs -as long as it induces breathlessness -can elevate your endorphins and up your mood.

Some doctors say that their SAD patients have a particular taste for carbohydrates. Opt for healthier carbs like vegetables, whole grains, and fruits which will help keep you energized.

Dr. Janet Taylor, a mental health community expert on BeWell.com,notes the importance of social interaction.

"You might be inclined to be socially isolated, but interacting with people, friends and family can really help create a support network," she says.

Margit Detweiler - Associated Press