Seasonal Affective Disorder (SAD)

According to the National Alliance on Mental Illness (NAMI), researchers disagree “whether SAD is a distinct mental illness or a specific type of major depressive disorder” (Duckworth and Freedman). There are two types of Seasonal Affective Disorder (SAD), a winter and summer version. Researchers conclude that only about five percent of adults in America have the winter variant of SAD, and less than one percent have the summer variant (Khazan). NAMI defines the classic winter form of SAD as “recurrent episodes of depression, usually in late fall and winter, alternating with periods of normal or high mood the rest of the year” listing the symptoms as “oversleeping, daytime fatigue, carbohydrate craving and weight gain” (Duckworth and Freedman).
The less common summer variation, manifests in the summer months rather than in the winter months, causing “insomnia, decreased appetite, weight loss and agitation or anxiety” (Duckworth and Freedman). While the definitive cause of SAD has yet to be determined, the effects of Seasonal Affective Disorder can be brought on by various factors. Several studies propose sensitivity to light, other environmental factors, mental health and possible genetic inheritance play contributing roles in causing this disorder.
Some studies suggest sensitivity to light and how it affects our bodies play a key role in triggering Seasonal Affective Disorder. The increase of daylight can throw off circadian rhythms in summer sufferers just as shortened daylight does. One contributing factor said possibly set off SAD is the intense summer light, causing our natural body clock to be thrown off by disrupting our circadian rhythm according Khazan, who mentions the idea of Alfred Lewy that people maybe be staying up later, throwing off their body clocks. The extended daylight hours may affect our natural sleep patterns to be thrown off leading to depression, insomnia, anxiety, weight loss, and lack of appetite. Body chemicals, like the body clock, are also affected by light. Examples include the hormones melatonin and serotonin. While Lewy reports that melatonin supplements may be prescribed for summer sufferers to help regulate sleep cycles; serotonin may be lacking in the brain causing depression. Goldberg seems to back Lewy’s information by saying, “One theory is that less sunlight during fall and winter leads to the brain making less serotonin, a chemical linked to brain pathways that regulate mood.” Melatonin is a natural hormone that our bodies produce and it regulates our natural sleep cycle and causes drowsiness. “Because the lack of enough daylight during wintertime is related to SAD, it's less often found in countries where there's plenty of sunshine year-round. (Goldberg). The shortened daylight in winter increases the production of melatonin, having an opposite effect of summertime insomnia, by producing symptoms of fatigue and the increased desire to sleep more.
Environmental factors such as allergies and temperature may also lead to the effects of Seasonal Affective Disorder.
Khazan possibly links summer SAD to allergies by saying, “One recent study suggests summertime SAD is caused by allergies, with people reporting worse moods on days the air was thick with pollen.” As temperatures begin to rise in the spring and summer, some people report feeling overcome by the symptoms of summer SAD. Professor Thomas Wehr an expert in summertime SAD says the effects of heat can be comparable to those of depression, causing sleep issues and lack of motivation. Khazan quotes Professor Wehr, who finds that when people with summer depression were “wrapped in cooling blankets at night, their temperatures dropped and their symptoms disappeared. As soon as they went outside into the summer heat, their depression returned.” Unlike its summertime cousin that generates depression in the hotter months; wintertime SAD “causes depression when the days grow short and temperatures drop” (Khazan). “Some studies have also shown that SAD is more common in people who live in northern latitudes” (Duckworth and Freedman). Patients with winter SAD often report when the temperatures begin to drop, their symptoms begin to increase. They become lethargic in colder weather; withdrawn, fatigued and just want to
sleep.
Finally, mental health and genetics could possibly be factors in Seasonal Affective Disorder.
Bi-polar disorder is a mental illness that causes shifts in a person’s mood, energy and ability to think clearly (Duckworth and Freedman). “Some people with bipolar disorder can also have seasonal changes in their mood and experience acute episodes in a recurrent fashion at different times of the year” (Duckworth and Freedman). Bi-polar disorder produces signs of reoccuring depression,mood swings and shifts in energy levels, as does seasonal winter and summer SAD. Just like Seasonal Affective Disorder researchers cannot pinpoint one particular cause of bi-polar disorder, but believe that genetics, stress and brain structure contribute to this mental illness (Duckworth and Freedman). Genetic Inheritance is perhaps linked to Seasonal Affective Disorder; one study connects the mental and genetic factors together by saying that more than two-thirds of people with Seasonal Affective Disorder also have a family member with a major mood disorder.
In conclusion, there are various causes that contribute to the effects of Seasonal Affective Disorder. Several studies suggest that light sensitivity, environmental factors, mental health and possible genetic links discussed in this report play key roles in causing the onset of symptoms of this disorder. While the exact cause of SAD has yet to be discovered, the evidence presented by various studies suggests that Seasonal Affective Disorder may
be brought on by many different elements.