Darkness. Freezing temperatures. Changing of the clocks. Shorter days. Reduced sunlight. The perfect (winter) storm for depression.
With the onset of the winter season delivering its shorter days and darker nights, some people experience a form of depression known as seasonal affective disorder (SAD). People who suffer from SAD experience mood changes and other symptoms of depression; the difference is their symptoms go away with the coming of spring.
The most difficult time for sufferers in the United States seems to be January and February. But is it all “in our head” or can we blame this seasonal illness on Mother Nature? Well, both, actually.
About 500,000 people in the U.S. are diagnosed with SAD, while 15% suffer from its milder form, known as the “winter blues.” Women represent 75% of people who suffer from SAD, but the disorder also affects men and children.
SAD has been linked to a biochemical imbalance in the brain caused by shorter days and less sunlight. With the onset of winter weather, people experience changes in their circadian rhythm or biological clock that can cause them to become out of synch with their daily schedule. In addition, living in geographic locations with reduced sunlight, such as Canada and Alaska, places them at risk.
It has been argued that SAD is an evolved adaptation within humans that is a remnant of prehistoric times when hibernation during the winter season was the norm. Reduced sunlight, fewer food sources, and diminished activity increased the difficulties of surviving cold weather.
While hibernation may seem an extreme example to some, even non-tropical animal species that do not hibernate often exhibit changes in behavior during the winter.
Symptoms of SAD can be minor or severe. They include feelings of sadness or depressed mood, difficulty thinking or concentrating; a loss of interest or withdrawal from regular activities; extreme fatigue; restlessness; feeling of worthlessness; thoughts of suicide; an increased desire to sleep; and cravings for carbohydrates leading to weight gain.
Increased exposure to sunlight can improve symptoms. Bright light therapy or phototherapy may also help;, this treatment provides patients with bright artificial light that mimics natural sunlight. Researchers believe the light “resets” the timing of the biological clock, lifting the mood and easing other symptoms.
Optimal light therapy requires three key elements: duration, timing and intensity. The timing and duration of the light treatment can be adjusted based on the symptoms. Those with SAD usually start light box therapy at 15 minutes every morning. Eventually, light therapy typically involves daily sessions ranging from 30 minutes to two hours, depending on the intensity.
Intensity of light box exposure is recorded in lux, a measure of the amount of light received at a specific distance from a light source. For example, a 10,000-lux light box typically requires a 30-minute session, while a 2,500-lux light box may require a 2-hour session.
Light boxes are designed with the same purpose, but one may meet the needs of the patient better than another. A light box can be purchased over the counter; however, most health insurance plans do not cover the cost.
Beyond light therapy, other treatments for SAD include
Although SAD is a fairly common disorder noted throughout the world, sufferers should be encouraged. The ability to imitate regular sunlight in the form of light box therapy is allowing many to experience a “return to normal,” regardless of the season or geographic location.