As much as winter can be enjoyable, people like us who live in the more northern parts of the world are susceptible to a peculiar type of depression associated with loss of daylight. More than the usual “winter blues”, seasonal affective disorder or SAD affects between 3 and 5% of adults in Canada, while another 10 to 15% have a milder form of the same disorder. Women between the ages of 20 and 40 are most susceptible to SAD, but it does occur in men and occasionally in older people as well. Not unlike a major depressive disorder, SAD sufferers start to feel chronically low and fatigued as fall grows into winter.
SAD also causes people to eat and sleep more than usual and when they eat, they have a particular craving for carbohydrates, which can lead to marked weight gain. Come the spring, symptoms lift and the person feels more like their normal self. Interestingly, in Vancouver where winters may not be as cold as they are elsewhere, but where dark gray days are the norm, a relatively high incidence of SAD has been noted. Conversely, people who move south where the hours of daylight are longer and the winters sunnier are less likely to experience SAD.
Treatment of SAD
Treatment of SAD usually takes the form of so-called light therapy, at least initially. Light therapy involves the use of bright, artificial light where each day for about 30 minutes, people sit in front of a special light box and absorb the light. Light can also be delivered by a special light cap or light visor, and there’s even talk of mounting therapeutic lights on eyeglass frames. (The more common light boxes are commercially available but people should not use them without consulting their doctor first).
Why light therapy works is not really understood but some people feel that the biological clock inside our brain runs slow in SAD people during the winter. Bright light might help reset this clock and restore normal brain function. Overall, light therapy relieves symptoms in about 65% of people with SAD.
If light therapy is unsuccessful, doctors may recommend L-tryptophan, a protein that has antidepressant qualities, a selective serotonin reuptake inhibitor (SSRI) or one of the newer cyclic antidepressants. As is true for other types of depression, SAD has been linked to abnormal levels of the brain chemical serotonin, which regulates mood as well as certain behaviors including eating and sleeping.
Improving the balance of serotonin in the brain improves depressive symptoms. About half of those affected by SAD will continued to experience symptoms over the next 5 to 10 years but others do recover completely. As good lifestyle measures, people who are susceptible to SAD should try to avoid junk foods with high sugar content, and crash dieting. They should also work next to a window and avoid enclosed rooms with no windows. Whenever possible, SAD people need to get outdoors, especially on sunny days, and increase their physical activity.
Do you have SAD?
SAD is a true depressive illness so that it carries all of the usual symptoms of depression including chronic feelings of being down, changes in sleep and appetite and feelings of hopelessness. These symptoms have to have occurred at a certain time of the year for at least two consecutive years. If you think you have SAD, you should discuss symptoms with a doctor.