Dr. MJ Bazos MD,
What is seasonal affective disorder?
Seasonal affective disorder (also called SAD) is
a type of depression that follows the seasons. The most common type of SAD is
called winter depression. It usually begins in late fall or early winter and
goes away by summer. A less common type of SAD, known as summer depression,
usually begins in the late spring or early summer. It goes away by winter. SAD
may be related to changes in the amount of daylight during different times of
How common is SAD?
As many as 6 of every 100 people in the United
States may have winter depression. Another 10% to 20% may experience mild
SAD. SAD is more common in women than in men. Although some children and
teenagers get SAD, it usually doesn't start in people younger than 20 years of
age. For adults, the risk of SAD decreases as they get older. SAD is more common
in northern geographic regions.
How does my doctor know I have SAD?
Although your symptoms are clues to the
diagnosis, not everyone with SAD has the same symptoms. Common symptoms of
winter depression include the following:
- A change in appetite, especially a craving for
sweet or starchy foods
- Weight gain
- A heavy feeling in the arms or legs
- A drop in energy level
- A tendency to oversleep
- Difficulty concentrating
- Increased sensitivity to social rejection
- Avoidance of social situations
Symptoms of summer depression
include poor appetite, weight loss and insomnia. Either type of SAD may also
include some of the symptoms that are present in other forms of depression.
These symptoms include feelings of guilt, a loss of interest or pleasure in
activities you used to enjoy, ongoing feelings of hopelessness, and physical
problems, such as headaches.
Symptoms of SAD keep coming back year after
year, and they tend to come and go at about the same time every year.
The changes in mood are not necessarily related to obvious things that would
make a certain season stressful (like regularly being unemployed during the
Is there a treatment for SAD?
Yes. Winter depression is probably caused by
your body's reaction to a lack of sunlight. Light therapy is one option for
treating winter depression.
If your doctor suggests you try light therapy,
you may use a specially made light box, or a light visor that you wear on
your head like a cap. You will sit in front of the light box or wear the light
visor for a certain length of time each day. Generally, light therapy takes
about 30 minutes each day throughout the fall and winter, when you're most
likely to be depressed. If light therapy helps you, you'll continue using it
until enough sunlight is available, typically in the springtime. Stopping light
therapy too soon can allow the symptoms to come back.
When used properly, light therapy seems to have
very few side effects. Side effects may include eyestrain, headache, fatigue,
irritability and inability to sleep (if light therapy is used too late in the
day). For people who have manic depressive disorders, skin that is sensitive to
light, or medical conditions that make their eyes vulnerable to light damage,
light therapy should be used with caution.
Tanning beds shouldn't be used to treat SAD. The
light sources in tanning beds are high in ultraviolet (UV) rays, which harm both
your eyes and your skin.
Your doctor may also want you to try a medicine
or behavior therapy to treat your SAD. If light therapy or medicine alone
doesn't work, your doctor may want you to use them together.