American Medical Association Family Medical Guide - American Medical Association [457]
The short daylight hours and lack of sunlight during winter can also cause a chemical imbalance in an area of the brain called the hypothalamus, which plays a role in regulating the body’s biological clock. Cold weather adds to the chemical imbalances caused by low light levels by encouraging people to spend more time indoors. Some doctors think that SAD may be the human counterpart to the seasonal cycles of animals that influence activities such as hibernation. SAD affects more women than men and is most common in people in their 20s and 30s.
Symptoms
The symptoms of SAD are severe and usually appear around September or October and continue until March or April. They are similar to the symptoms of depression (see page 709), including decreased energy, excessive sleepiness, or fatigue. In some cases, a person has feelings of sadness and a decreased interest in sex or physical contact. He or she may withdraw from family and friends. Many people with SAD gain weight, perhaps because of an increased appetite and a craving for carbohydrate-rich or sugary foods.
The symptoms subside in the spring and summer, either gradually with increasing sunlight or suddenly. Some people experience bursts of energy or creativity or elevated moods during this time, similar to the manic episodes that occur in bipolar disorder (see previous article).
Diagnosis
A diagnosis of SAD can usually be made after two or more consecutive winters of symptoms of depression that go away when the weather turns warmer and daylight increases. People with SAD may notice that their symptoms recur or worsen if the amount of indoor light they are exposed to decreases or if the weather is overcast at any time of year. A doctor may recommend a thorough physical examination and laboratory tests to rule out other possible conditions. If your doctor thinks you may have SAD or another type of depression, he or she will refer you to a mental health professional who has experience treating the various forms of depression, including SAD.
Other Types of SAD
Many people gain weight and lack energy at times in the fall and winter. This mild form of SAD, called winter depression or winter “blues,” is a more moderate reaction to seasonal variations in light than SAD and often occurs around the time of the winter solstice (December 21). Some people who think they have the winter blues may simply be coming down with the holiday blues, a time when they are likely to eat more.
A reverse form of SAD, called summer depression, is characterized by irritability, insomnia, and decreased appetite with accompanying weight loss. Symptoms of reverse SAD may be related to the excessive heat of summer rather than to a reaction to light.
Treatment
Light therapy (phototherapy) provided by a fluorescent light box or by wearing a visor with a fluorescent light attached is commonly used to treat SAD. The amount of light needed to provide effective therapy varies from one person to another. Phototherapy usually is done in the morning or early evening to extend the feeling of daylight. Your doctor will monitor the therapy carefully because of possible side effects such as eyestrain, headache, and insomnia.
If you have SAD, try to expose yourself to daylight as much as possible. Outdoor light, even on a cloudy day, is brighter and can provide more light than a light box. Daily exercise can be helpful in treating SAD and is especially beneficial when done outdoors. Eating a balanced diet can help to offset cravings for carbohydrates and sweets.
Antidepressant medications (see page 712) may be effective in eliminating or at least reducing the symptoms of SAD. Psychotherapy (see page 710) can often help people with SAD deal with their depression. Some people benefit from a combination of light therapy, medication, and psychotherapy.
Anxiety Disorders
The human body evolved a rapid hormonal response system to deal with danger and to ensure survival. Our physical reactions to dangerous or stressful