Question: I have a couple of friends who always seem to be down around this time of year or their mood changes considerably. Could it be Seasonal Affective Disorder? And what can be done to "cheer" them up, if anything?
Never miss a local story.
Answer: Some people feel less energetic, lose interest in their leisure time activities and have difficulty adjusting to the reducing daylight and decreasing temperatures in the fall and winter months.
It is colloquially referred to as the "winter blues" if it is transient and not disabling.
When the intensity and duration of the episode is severe and has certain other associated symptoms of clinical depression then it may be called a depressive episode.
A depressive episode can occur at any time of the year. However, some people experience them exclusively in fall and winter and feel "normal" during spring and summer.
It is called Seasonal Affective Disorder ("affective" is the medical term for mood) or SAD.
SAD is not a separate illness. It is a subtype of major depressive disorder or bipolar disorder. SAD is more common in Canada and the northern United States.
One theory suggests that SAD is a disturbance of the "biological clock" of the brain that regulates hormones, sleep and mood.
This clock is delayed in the winter due to reduced sunlight. It is noted that reduced sunlight can trigger a drop in the serotonin, a brain chemical involved in mood regulation.
The change in season can also disrupt the level of melatonin in our body leading to change in sleep and mood.
SAD is characterized by increased sleep, marked fatigue, overeating and weight gain, in addition to sadness of mood.
It is very suggestive of the hibernation behaviors of some animals (like bears) that sleep away during the winter months.
Research has shown that treatment with "light therapy" for 30-60 minutes a day can improve the symptoms by 60-70 percent .
Light therapy can also help a lot of people with the winter blues. The "dose" of light needed to make this change is about 10,000 lux.
Lux is the measurement of the intensity of indoor light. The usual indoor light is about 400 lux. The brightest offices and stores usually have an intensity of about 1000 lux.
In other words, the light box is about 10-20 times more intense than the lights we are usually exposed to in our daily life.
Most light boxes emit white light and are safe and inexpensive. The light boxes are made of fluorescent bulbs with a special filter that block the UV rays or LED lights that do not emit UV rays.
There is no evidence of sun tanning studios to be helpful for SAD. Light therapy has its effect through the eyes and not by exposure of skin to the light. People should not open their eyes in the tanning booth as it emits harmful ultraviolet rays.
A lot of residents of Hilton Head and the Lowcountry are migrants from the northern states in search not only of warmer weather but also daylight hours which helps treat SAD.
Despite having comparatively better weather than the northern states there is enough reduction in daylight hours and longer, darker, gloomier nights to cause some people to have symptoms suggestive of SAD.
If your depression symptoms have exclusively occurred in winter months for more than three consecutive years, then discuss its seasonality with your doctor as antidepressants and psychotherapy may not be the only treatment option for you.
Follow reporter Mindy Lucas on Twitter at twitter.com/MindyatIPBG.
Professional Opinion: Alzheimer's and the holidays -- looking out for the most vulnerable during the busy season, Dec. 8, 2015
Professional Opinion: Going to the dentist? There are fewer reasons to fret today, Dec. 14, 2015
Key words: medical, professional, opinion, expert, expertise, advice, doctor, physician, hilton head, island, beaufort, bluffton, coast, psychiatrist, Ravi, Srivastava, winter, blues, SAD, Seasonal, affective, disorder, health, wellness, condition, disease, therapy, depression, mood, holiday, light