Christine M. Muller
Abnormal Psychology
Jeffrey Geibel, PhD.

Seasonal Affective Disorder

It's wintertime, and you feel stressed, lethargic and disconnected from everything and everyone around you. "Maybe it is just the winter blues," you tell yourself. However, the depression and other symptoms continue to persist from the beginning of winter until the springtime, every year. Although you may believe that you, like many other people, are bothered with a case of the winter blues, you are most likely suffering from a more severe form of seasonal depression known as Seasonal Affective Disorder, or SAD. This form of depression has been described as a form of a mood disorder that, unlike other forms of depression, follows a strictly seasonal pattern.
In general, many people suffer from some form of sporadic depression during the wintertime. We may feel more tired and sad at times. We may even gain some weight or have trouble getting out of bed. Over 10 million people in America, however, may feel a more extreme form of these symptoms. They may constantly feel lethargic and depressed to an extent that social and work related activities are negatively affected. Typical SAD symptoms include sugar cravings, lethargy, depression, an increase in body weight, and a greater need for sleep. Onset of these symptoms usually occurs in October or November, and the symptoms disappear in early spring. Frequently, people who suffer from SAD react strongly to variations in the amount of light in their surrounding environment. Most often, patients who suffer from SAD note that the more north they live, the more distinct and severe their SAD symptoms become. In addition, SAD patients note that their depressive symptoms increase in severity when the amount of light indoors decreases and the weather is cloudy. Out of all of the patients who suffer from SAD, 70-80% are female.
Multiple theories exist as to the origins of SAD, although the exact cause is currently unknown. A strongly held thought is that the lack of sufficient sunlight can lead to the disorder. Simply being in a room without windows for an extended period of time can trigger a depressive episode in SAD patients. The body's circadian rhythms, which regulate an individual's daily sleep-wake cycles, are disturbed when sunlight is not as prevalent. This is the reason why individuals with wintertime SAD often experience a difficulty in waking up in the morning during the longer nights of winter.
Scientists have also hypothesized that the disorder could be due to a decrease in serotonin; a key neurotransmitter in the brain, and the production of serotonin has been thought to be caused by the presence of sunlight. Also, research has found that this disorder could also be due to an increase in the level of melatonin, a hormone that is connected to sleep. The higher level of this hormone in SAD patients during the longer periods of darkness during winter have also been thought to be linked to their depressive symptoms, along with the decrease in serotonin.
So then naturally, it would seem reasonable that one of the main proposed treatments for SAD (aside from medication and psychotherapy, which have been proven to be effective) is an added source of light during the longer periods of darkness which occur during the wintertime. In this form of treatment, the light, which is between 10 and 20 times stronger than a regular room light, is placed several feet from the patient. The patient sits in front of this light in the morning (so as not to cause insomnia, which nighttime light therapy may cause) for at least a half an hour. Although multiple light sources can be used in the treatment of SAD, choosing the proper kind of light therapy, which will not only be effective for use but safe for use as well is very important. Neither UV light nor full spectrum light should be used in the treatment of SAD; both have proven to be ineffective during light therapy trials. Most often, high-intensity light boxes which do not emit UV wavelengths have been used to treat the symptoms. Also, a special dawn simulator can be used. This very strong light is placed beside the person's bed, and its intensity is slowly increased to reach its greatest strength when it’s time to wake up. The only rare side effects seen from the forms of light therapy used have been eye strain, nausea, irritability and headaches, and these often subside as the person gets acclimated to the therapy. Outdoor light, which provides just as much light as the light boxes (even when the sky is cloudy) has also been shown to decrease SAD symptoms. Those who took just a daily 60-minute walk showed better mood.

References

1. Information and Frequently asked Questions about Seasonal Affective Disorder, From PhoThera Light Products http://www.phothera.com/ptfaq.html 2. Seasonal Affective Disorder, From Mayo Clinic http://www.mayoclinic.com/invoke.cfm?id=DS00195 3. Seasonal Affective Disorder, from mentalhealth.com
http://www.mentalhealth.com/book/p40-sad.html