At this time of the year, a lot of us joke about having what is known as, "Seasonal Affective Disorder." Stress from the holidays and the annual push to accomplish aggressive goals prior to the end of the calendar year become a popular topic for discussion around the water cooler.

The fact is, SAD is real and science continues to reveal more each year about this "change of mood" many of us experience when a "change of season" occurs. SAD was first used in a paper written by Norman Rosenthal in 1984. It is now classified as a mood disorder "subset" in which people who have normal mental health throughout most of the year experience depressive symptoms in the winter or summer – and yes, it happens when the weather's nice. Experts were initially skeptical about this condition, but its prevalence in the U.S. ranges from 1.4 percent in Florida to right at 10 percent in Alaska.

No longer considered a unique mood disorder but, rather a "specifier" with a seasonal pattern for recurring depression that occurs at specific times of the year and then fully remits (goes away).

Symptoms of SAD may include a lack of energy, difficulty waking up in the morning, nausea, a tendency to oversleep and over-eat (especially carbohydrates), which can lead to weight gain. Other symptoms apart from the physical ones include difficulty concentrating on or completing tasks, withdrawal from friends, family, and social activities, and a decreased sex drive. No wonder Scrooge was particularly nasty around the holidays.

Why does this occur? Historically, for many non-tropical species, including humans, activity slows during the winter months in response to the reduction in available food and the reduction of sunlight. And, while the specifics are not known, that reduction in sunlight is highly suspect in "Grinchy" moods:

Circadian Rhythm: Reduced sunlight can disrupt your body clock.

Serotonin levels: Reduced sunlight can cause a drop in serotonin, a brain chemical (neurotransmitter) that may trigger depression.

Melatonin levels: Light affects how much melatonin your body produces. Seasonal changes can disrupt the balance of the body's level of melatonin, a hormone made by a small gland in the brain which plays a role in sleep patterns and mood.

Am I prone to SAD? The Mayo Clinic suggests there are risk factors for this condition. They include:

Being female. Four out of five people diagnosed with SAD are women, but men may have more-severe symptoms.

Age. Young people have a higher risk of winter SAD, and winter SAD is less likely to occur in older adults.

Family history. People with SAD may be more likely to have blood relatives with SAD or another form of depression.

Having clinical depression or bipolar disorder. Symptoms of depression may worsen seasonally if you have one of these conditions.

Living far from the equator. SAD appears to be more common among people who live far north or south of the equator. This may be due to decreased sunlight during the winter and longer days during the summer months.

What's to be done? Treatment for seasonal affective disorder may include light therapy, medications and psychotherapy.

Light therapy has become a popular treatment for SAD, as it generally starts working in a few days to a couple of weeks and causes few side effects. Light therapy mimics natural outdoor light and appears to cause a change in brain chemicals linked to mood.

Psychotherapy, or talk therapy is another option. Psychotherapy can help you manage stress and recognize and change negative thoughts that may be blocking your ability to cope with SAD.

Antidepressant medications may be prescribed by your doctor. These can take weeks to begin working and do come with side effects. If you suffer from bipolar disorder, it is critical for your doctor to know if they plan to prescribe light therapy or antidepressants. Both can potentially trigger a manic episode.

It's normal to have some down days through the season. But if your sleep patterns and appetite have changed for days on end, you withdraw from activities and people you normally enjoy, or have feelings of hopelessness or suicide, it's time to see your doctor.

If you feel you may have SAD and are in need of a primary care physician:

• Blue Springs Internal Medicine, 816-228-9841

• Family Medical Care Associates, 816-228-1000

• Oak Grove Medical Clinic, 816-690-6566