We all get the winter blahs from time to time. For some people, though, it's more than just a little blue mood. By some estimates, as much as 10 to 20 percent of the population may suffer from mild to moderate forms of Seasonal Affective Disorder or "winter depression."

Depression is a serious concern in senior healthcare, as it can have a greater impact on the mental health of older adults than it does for the general population. And seniors are at particular risk of developing depression— almost 1 in 7 people over the age of 65 are thought to exhibit the signs of clinical depression, according to mental health experts.

What is Seasonal Affective Disorder?

Seasonal Affective Disorder (SAD) is complex of symptoms, including depression and unpredictable mood swings, which occur when ambient light levels diminish during the winter and fall as the sun moves progressively lower in the sky. The depression and mood swings are often associated with a dip in the serum blood level of serotonin, a neurotransmitter that helps to regulate mood, and melatonin, a serotonin-derived neurotransmitter that regulates sleep patterns.

Mammals (including humans) have an area of the brain called the pineal gland, which regulates the production of melatonin. Some researchers believe that this region of the brain is able to detect small changes in ambient light and sun angle over time, and thus upregulate or downregulate the brain's serotonin and melatonin production.

Since melatonin is only produced in low light, in the winter the human pineal gland may use more free serotonin to create more melatonin, thus reducing the body's overall serotonin level. Low serotonin has long been suspected as a cause of clinical depression. In fact, some antidepressant drugs work by preventing brain cells from reabsorbing serotonin, thus increasing the level of free serotonin which, in turn, elevates mood.

Some researchers believe that people who suffer SAD may simply have an overly active pineal gland, or may produce less serotonin on average than a person without the condition. Either way, it is a serious, life-affecting problem for many people. Seniors with SAD may get hit particularly hard, as they are often less active and stay indoors (where light levels are lower) more than younger people.

What you can do to beat the winter blues.

The keys to feeling better are getting more light and more exercise. Although you can't increase the amount of sunlight available outside, you can take steps to brighten up your home's interior or to get more sunlight while the sun is up.

If the weather isn't too cold or icy, or if you can dress appropriately for it, get outside and take a stroll for 20-30 minutes twice a day. If you can't get out, draw up the blinds and open shutters over windows to allow more ambient sunlight into your home.

If you have a fireplace, use it. Sitting in front of an evening fire on cold, dark winter nights may help to keep your melatonin production normalized. In fact, the holiday tradition of lighting the Yule log (which later evolved into the lighting of candles and hanging of Christmas lights), which occurs near the winter solstice (the shortest day of the year in the Northern hemisphere), probably originated as a way to combat the winter blues and cheer up the residents of Northern Europe during the darkest winter days.

If that doesn't help, there are special light therapy devices that SAD sufferers can buy and use to try and reduce symptoms.

Serotonin reuptake-inhibiting medicines (SSRIs) like Prozac and Zoloft can also be helpful in breaking severe depressive cycles, but these must be carefully monitored by a doctor.

You cannot simply start and stop them at will, however. They take several weeks to build to effective levels. You must also wean off them gradually, or risk life-threatening serotonin syndrome.

Moderate exercise increases serum serotonin and also triggers the production of the pain-relieving hormone dopamine.

Joining a gym or the YMCA and beginning a regular indoor exercise program can help to reduce the symptoms of depression and even alleviate some chronic pain. Not only can a senior combat the winter blues, he or she can increase his overall wellness and strength, just by getting more active!