Seasonal affective disorder is a cyclic, seasonal condition. This means that signs and symptoms usually come back and go away at the same times every year. Usually, seasonal affective disorder symptoms appear during late fall or early winter and go away during the warmer, sunnier days of spring and summer. The most difficult months for SAD sufferers seem to be January and February. Younger adults and women are thought to be at higher risk for developing symptoms. SAD may begin at any age, but the main age of onset is between 18 and 30 years.

The precise cause of seasonal affective disorder isn't known, but genetics and age may be factors. Most evidence, though, suggests that it arises from abnormalities in how your body manages its internal (circadian) biological rhythms or matches those rhythms to the 24-hour day. In particular, the hormone melatonin is thought to play a major role in seasonal affective disorder. Melatonin helps control body temperature, hormone secretion and sleep. It's produced in a specific area of your brain during the hours of darkness.

Fortunately, there are safe, effective, drug-free treatments that can minimize the symptoms of SAD. One of the most popular ways to deal with SAD is through light therapy. Research shows that light can help get the body clock back in sync. Light therapy mimics outdoor light and causes a biochemical change in your brain that lifts your mood, relieving symptoms of seasonal affective disorder. In light therapy, you sit a few feet from a specialized light therapy box so that you're exposed to very bright light. To be effective, light therapy must be delivered by a special bulb that offers the sun's spectrum of colors and the sun's intensity. If you use light therapy, it is important to stick to your regime because it will only work if used regularly.

The general recommendation for most people with seasonal affective disorder is to begin treatment with light therapy in the early fall, as soon as the earliest symptoms start. Be on the alert for symptoms such as difficulty waking, daytime sleepiness and carbohydrate cravings. Treatment generally continues until spring, when outdoor light alone is sufficient to sustain a good mood and higher energy.

Yours in good health,