By Matthew Solan, Natural Solutions

For 12 years Helena Davis’ life resembled a light switch. When daylight-saving time arrived in spring, it flipped on–she felt energetic, focused, and active. In winter, however, it switched off. She struggled to do the simplest household chores. Her weight ballooned. She could go to work and function at some level, she says, but it was obvious that something was wrong. “All winter I felt like a slug moving around in peanut butter,” says Davis, now 64.

She finally realized that her mood change coincided with her move to upstate New York, an area with few sunny days. A visit to her doctor filled in the diagnosis: Davis was one of 10 million to 25 million Americans, 75 percent of whom are women, who suffer from a subtype of depression called seasonal affective disorder (SAD).

You’ve no doubt heard of SAD. Also called “winter blues,” it often gets mistaken for clinical depression as the two share many symptoms–sadness, anxiety, lethargy, lack of sleep, diminished sex drive, and increased appetite. The difference lies in their duration and severity, according to Norman Rosenthal, MD, author of Winter Blues: Everything You Need to Know to Beat Seasonal Affective Disorder (The Guilford Press, 2006). SAD typically strikes around September or October and then fades away in March and April. (Depression on the other hand can occur year-round.) Merely troublesome and potentially disruptive at first, SAD can be controlled if you take appropriate action, but “left unchecked, the changes in mood and behavior can become so powerful they can create significant problems in your life and may manifest into year-round major depression if not addressed,” says Rosenthal.

Light therapy
The primary cause of SAD is light deprivation, so light therapy ranks as the first line of defense. Light boxes contain white fluorescent bulbs behind a plastic UV filter, and regular use can reset your body clock and increase serotonin. Effective light boxes generate 10,000 lux (a measurement of intensity); to put that therapeutic amount in perspective, traditional lighting produces 300 to 500 lux, and the sun produces more than 100,000 lux on a bright summer day.

Rosenthal recommends using light therapy for about 20 minutes a day at first, ideally in the morning. How early depends on the individual’s body clock, says Michael Terman, PhD, who heads the Center for Light Treatment and Biological Rhythms at Columbia Presbyterian Medical Center in New York.

If you suffer from SAD, try placing a light box 1 to 3 feet away while you eat, read, go through your mail, or meditate. If your symptoms remain unchanged, increase your treatment to 45 minutes a day, says Rosenthal. Reevaluate your symptoms on a weekly basis and make adjustments. “You should feel the effects within two to four days,” says Rosenthal. “Almost everyone should feel the benefits within two weeks.” (Find light boxes at lightforhealth.com or litebook.com.) Brighten up your living and work space with full-spectrum light bulbs that closely match natural daylight.

Diet and exercise
Dietary changes also can ease SAD symptoms, says Chris Krumm, ND, LAc, of the Bastyr Center for Natural Health, near Seattle. For breakfast, Krumm advocates a high-protein meal to boost intake of tyrosine. “Consuming this amino acid in the morning helps boost your energy throughout the day,” he says. For dinner, Krumm suggests less protein and more carbohydrates like whole grains to help the brain synthesize serotonin. “In addition to improving your mood, increased serotonin may help people sleep better,” he says.

You may want to add more fish to your diet, too, especially cold water types like mackerel and salmon that are rich in omega-3 fatty acids. People with depression often have low levels of omega 3s. A 2001 study found a correlation between increased fish consumption and decreased incidence of SAD in Iceland.

Davis has found that staying active in winter helps her feel less lethargic. She’s chosen a treadmill inside a brightly lit gym, but don’t be afraid to head outside. On bright afternoons, go for a long walk or run. Got more time? Climb on a bike or break out the skis. “You’ll get your required light exposure and also some exercise, which can help alleviate stress that may contribute to SAD-related depression,” says Rosenthal. Research in BMC Psychiatry found the combination of bright light exposure and aerobics reduced many depressive symptoms, especially those related to insomnia and other sleep problems.

Next: Sweet dreams and SAD symptoms