Seasonal Affective Disorder
the winter blues
About 20 years ago, soon after coming to the National Institute for
Mental Health, psychiatrist Norman Rosenthal, M.D., worked with two
people who became clinically depressed each winter. Although he
suspected such symptoms were rare, he wondered whether other people in
the Washington, D.C., area might share a similar problem.
He didn't have to wonder long. After an article about his work
appeared in The Washington Post, he heard from thousands of people
nationwide. The research that followed led to a new psychiatric
diagnosis — seasonal affective disorder, or SAD.
Dr. Rosenthal estimates that 10 million to 25 million Americans
experience depression that recurs in seasons with less daylight. Most
affected people are women, although SAD may occur in men and children.
Among psychiatric conditions, SAD is fairly new. Yet descriptions of
seasonal depression go back for centuries.
Signs and symptoms
"Affective" means "emotional," and some of the
primary effects of SAD relate to feelings. Yet SAD affects behavior as
well.
Signs and symptoms of SAD include:
- Depression
- Loss of energy
- Anxiety
- Irritability
- Increased sleep
- Loss of interest in sex
- Overeating, especially foods high in carbohydrates
- Weight gain
- Difficulty concentrating and processing information
A diagnosis of SAD requires that a person has experienced depression
and other symptoms in at least two consecutive winters, followed by
non-depressed periods in the spring and summer. Also, there must be no
other explanation for the changes in mood and behavior. It's often
difficult to diagnose SAD because other disorders may mimic SAD.
SAD remains elusive
A lot of questions about SAD are not fully answered.
What causes SAD?
Researchers first thought that lack of sunlight affects levels of
melatonin, a hormone. However, studies on the role of melatonin in SAD
are inconclusive. Some researchers believe that a lack of sunlight
disrupts circadian rhythms, which regulate your body's internal clocks.
Is SAD more common in northern countries with longer winters?
There's evidence that SAD occurs more often in people who live in
higher latitudes. Yet SAD also occurs in southern countries such as
India.
How is SAD best treated?
Light therapy is currently the treatment of choice. This involves
exposing people to special lamps that are 10 to 20 times brighter than
ordinary indoor lights. Three studies published in the October 1998
issue of Archives of General Psychiatry concluded that such light
therapy is most effective when administered as the first thing upon
waking up in the morning.
In an accompanying editorial, David H. Avery, M.D., of the Department
of Psychiatry and Behavioral Sciences at the University of Washington
School of Medicine, wrote: "All 3 studies add to the literature
suggesting that morning bright light is superior to evening bright
light, a good control condition. Together, the placebo-controlled trials
and morning-vs-evening studies strongly support the efficacy of morning
bright light in the treatment of SAD and help establish bright light
therapy as a first-line treatment for SAD."
Even so, the mechanism by which light therapy works is not fully
explained, and it's also clear that light therapy doesn't work for
everyone.
Seeking professional help
Despite the uncertainty about SAD, you can do something about
depression.
Sheila G. Jowsey, M.D., a psychiatrist at Mayo Clinic, Rochester,
Minn., has this suggestion about seeking professional help: "If you
feel down for days at a time and life seems to be losing its pleasure,
see your doctor. This is particularily important if you notice that your
sleep and appetite are affected — and especially if you think about
suicide." Dr. Jowsey says a physician can help you detect seasonal
patterns in your emotions.
"We're concerned about the person who has a sustained depressed
mood," adds Dr. Jowsey. "All of us have a few days when we're
down, but if your mood stays down, then it's time to get help."
Options for treatment
Although light therapy is widely used for SAD, there are other
treatment options, including antidepressant medications and counseling.
You should discuss treatment options with your physician or mental
health professional.
If you're diagnosed with SAD, you can also make lifestyle changes.
For example, Dr. Rosenthal suggests:
- Increase the amount of light in your home. Add lamps or skylights.
Trim tree branches that block sunlight.
- Walk outdoors on sunny days, even during winter.
- If possible, take winter vacations in a sunny, warm location.
- Exercise regularly.
- Experiment with sleeping less and eating fewer carbohydrates.
- Learn ways to manage stress.
