Last Updated on August 30, 2016

Feeling depressed, sleepy, and out of sorts this winter? You could have seasonal affective disorder, also called SAD.

It’s no secret people get SAD in winter. You may recognize the symptoms in yourself or someone close to you: a pervading sense of blues and stress; deficiency of energy; sleepiness and attempting to remain in bed; little interest in your social life; difficulty concentrating; weight gain.

“In seasonal affective disorder, the depressive symptoms are present only through winter months or become worse during the wintertime, when nights are longer,” says sleep practitioner Meir H. Kryger, MD, a professor at the Yale School of Medicine and lead writer of Elsevier’s Principles and Practice of Sleep Medicine (Elsevier, 2012). In addition to the sadness, individuals will generally put on a great deal of weight due to changes in the amounts and timing of the release of hormones that influence hunger. SAD is therefore not regarded as a separate disorder, however a variant of depression. A milder variation of the disorder has been described as Subsyndromal Seasonal Affective Disorder, or SSAD, in which the apparent symptoms of depression are much less severe.”

We asked Dr. Kryger about why SAD affects us and how to feel better:

Everyday Health: What precisely is Seasonal Affective Disorder?
Dr. Kryger: Seasonal affective disorder is believed to be a wintertime return or worsening of depression. The symptoms of depression include feelings of worthlessness that is hopelessness, pervasive despair, or helplessness, loss of interest in pleasurable activities, reduced energy, in the most severe cases, thoughts, as well as eating too little or too much of suicide. Sleep difficulties can also be common in depressed people and these contain having trouble falling or staying asleep, waking up too early each morning, if not sleeping in the day. The emotion of sadness could be normal in reaction to events that occur around us, but when the hopelessness interferes with his or her life and becomes pervasive and engulfs a man, depression is present and should be treated. During a given year, about 5 percent to 10 percent of the whole adult people will have depression. About 16 percent of the adult population will endure depression throughout the course of their life.

Are women impacted more than men – so?
Girls tend to be more prone to be diagnosed with SAD, and this might merely reflect the increased susceptibility of women to depression. This is examined for example, in Alaska, by the University of Alaska Anchorage. About 9 percent of the people seems to have SAD as well as the risk of getting SAD is in females than males. SAD was more common in younger compared to older individuals.

At what time of year are folks most impacted?

The illness appears to recur as light exposure begins to decrease with the shortening of days in the late fall. Daytime are shortest (and nighttime longest) the third week of December in the Northern Hemisphere and during the 3rd week of June in the Southern Hemisphere.

What regions of the entire world are affected?

The closer geographically one lives to the North and South Poles, the greater the decrease in day and also the much more likely that SAD will undoubtedly be present. However, there is some data that indicates that some populations (for example, people of Icelandic descent) may be protected from developing SAD even though they live at latitudes where one would expect many people to possess SAD.

Do less light and shorter days impact human hormones?
Melatonin is a hormone that is produced in the pineal gland in the brain when it is dark outside. However, an increased degree of melatonin is only one explanation for SAD. The circadian system has a period delay, when days are shorter and nights longer. Quite simply, the functions and timing of hormone secretions during sleep that are controlled by the circadian system happen later. The circadian system needs exposure to sunlight to resynchronize the many functions of the body that are linked to time. Furthermore, even though one might anticipate an extended nighttime would raise the quantity and quality of sleep time, there’s a reduction in percentage of time in bed asleep. In addition, it takes longer time there’s poorer sleep quality, and overall less sleep time in winter. The mix of factors can affect several hormone systems involved with metabolism and appetite control also.

Why do people crave more carbohydrates and experience weight gain?
The consequent circadian desynchrony and shorter sleep time may influence levels of hormone that control desire (leptin and ghrelin) and may adversely alter the body’s metabolism and reaction to the hormone insulin (effects on insulin sensitivity). The effect of the changes in time and the amounts of hormones result in weight gain. That is why individuals with SAD typical gain weight during winter.

What qualifies SAD as a different disorder from depression or MDD (major depressive disorder)?

SAD is by definition seasonal. However, it might be that SAD isn’t a different entity but that decreased exposure to sun precipitates or worsens depression in susceptible people. Recent research indicates that the susceptibility may be associated with genetic variations in the coding to get a pigment. This pigment is light sensitive and is present in specialized cells in the eye that are believed to play a role in resetting the biological (circadian) clock in the brain.

Is there any signs that a modern disorder is it or impacted our ancestors?
This is likely not a modern disorder and has likely changed people living in northern climes nicely before modern times. Seasonality is available throughout biology. Hibernation along with the seasonality of reproduction of some species are two examples.

What are the primary treatments
Bright light: A thirty minute exposure to glowing The iGuide to Sleep.

Medicine: Antidepressants really are a modality of treatment recommended for SAD. Although there’s evidence supporting the utilization of antidepressant in severe depression, the quality of the evidence supporting the use of the hottest antidepressants especially for SAD is unimpressive.

What is your advice to individuals who may be dealing SAD?

1. Speak to your doctor or health care provider to ensure you have SAD. You may need medication or other treatment.

2. Around October, as the days become shorter, make an effort to be exposed to sun each day. However, never stare directly in sunlight!

3. Consider getting one of the particular lamps promoted for this particular purpose if it’s dim each morning. The blue increased lamps may be more efficient at lower strength.

4. A 30-minute exposure to natural sunlight or an artificial lamp ought to be adequate to prevent SAD symptoms.

5. If the outward symptoms of depression usually do not improve, contact your physician.