Are you sleeping more than usual, but still feeling tired? Does it seem impossible to get your energy up? Are you craving and eating more sweet or starchy foods? If so, your symptoms might have something to do with yesterday.
Yesterday was the shortest day of the year, and the first official day of winter. But by almost imperceptible minutes per day, the amount of daylight increases from here on. We’ve made it through the darkest days. And yet, for some, the dark days are just beginning.
A form of depression, Seasonal Affective Disorder (SADS) ebbs and flows in some people in unison with the arrival and departure of the darkest seasons of the year. For sufferers, symptoms most often begin late in the fall and early winter, waning when the days grow longer—in spring and summer.
According to a recent article by the National Institute of Mental Health (NIMH): “Depressive episodes linked to the summer can occur, but are much less common than winter episodes of SAD.”
NIMH explains that Seasonal Affective Disorder is not given a separate mental illness identity, but is a branch of depression. “To be diagnosed with SAD, people must meet full criteria for major depression coinciding with specific seasons (appearing in the winter or summer months) for at least [two] years.”
Statistically, SAD is diagnosed more often in women and in greater numbers for people living in the far north, or far south of the equator. SAD can occur in children and adolescents, but, of the overall population, SAD tends to be of greater risk to young adults.
Although the question of what causes SAD has yet to been answered definitively, the NIMH article describes biological clues researchers have discovered about the disorder. “People with SAD may have trouble regulating one of the key neurotransmitters involved in mood, serotonin.” Serotonin was found to be as much as five percent higher in SAD sufferers during the winter months than summer months—in comparison to people not diagnosed with SAD.
Another clue is the amount of the hormone melatonin that is present in some people. Since melatonin is produced in humans when it is dark outside—naturally encouraging sleep, the shortening of days before the winter solstice increases melatonin production. For some, however, the increase can lead to lethargy, fatigue, and “delayed circadian rhythm”.
A deficiency in Vitamin D may also be related to the seasonal depression since it has been scientifically linked to influencing the action of serotonin.
Kelly Rohan, Ph.D. is associate professor of psychology at the University of Vermont and an expert on SAD, and recently completed a NIMH-sponsored “clinical trial” that compared patients with SAD treated with light therapy with SAD patients who were treated with cognitive behavioral therapy (CBT).
Rohan discussed the results of her experiment in a 2013 interview for the American Psychological Association’s website. When asked when people should look for help with SAD and what types of treatments exist, Rohan emphasized the importance of recognizing the seriousness of the illness.
“I strongly recommend against self-diagnosis and self-treatment because depression, including SAD, is a serious mental health problem,” she said. If as a result of the typical symptoms of the illness, “you have difficulty functioning at school or work or if your symptoms interfere with your ability to interact with your family or others during the winter months, you should talk to your doctor about a referral to a psychologist.”
According to Rohan, light therapy is the most widely administered SAD treatment, providing sufferers with exposure to artificial light on a daily basis during the “symptomatic”, darker months. “Light therapy devices . . . emit a controlled amount of cool, white fluorescent or full spectrum light with a built-in screen to filter out harmful ultraviolet rays,” she explained.
Although light therapy devices are available in stores, Rohan underlined the importance of relying on a psychologist who specializes in the treatment “. . . because of the possible side effects, such as headache, eye strain and feeling agitated, and because the dose of the light needs to be adjusted to each patient.”
Rohan explained the findings of her experiment using cognitive behavioral therapy (CBT) as a SAD treatment by itself, and also used in combination with light therapy. “CBT is a type of talk therapy used and researched extensively for non-seasonal depression since the 1960s,” she began.
Results showed SAD improvement with CBT alone, light therapy alone, and also in combination therapy. “A year later, patients who had been treated solely with CBT generally had better outcomes than those who had been treated with light therapy alone,” she said. “In contrast, the combined treatment group did not fare any better than the light therapy only group the next winter. These results suggest that treating someone initially with just CBT may be more effective in the long term.”
In her 2015 article for CNN.com, writer Carina Storrs referred to psychologists and researchers using light therapy studies for SAD symptoms—like Rohan’s--as motivation for exploring the use of light therapy as an add-on for non-seasonal depressions. Dr. Raymond W. Lam, a professor of psychiatry at the University of British Columbia in Vancouver, Canada was the lead author of a 2009-2014 study on the subject. Based on the results, "clinicians should be confident in thinking this is an option," Lam concluded.
American Psychological Association. (February 4, 2013). Seasonal Affective Disorder Sufferers Have More Than Just Winter Blues. http://www.apa.org/news/press/releases/2013/02/seasonal-disorder.aspx
Lam. R.W., M.D., Levitt A.J., MBBS, Levitan R.D., M.D., M.Sc., et al. (January 2016). JAMA Psychiatry. Efficacy of Bright Light Treatment, Fluoxetine, and the Combination in Patients With Nonseasonal Major Depressive Disorder. https://jamanetwork.com/journals/jamapsychiatry/fullarticle/2470681
National Institute of Mental Health. (Retrieved December 21, 2017). Seasonal Affective Disorder. https://www.nimh.nih.gov/health/topics/seasonal-affective-disorder/index.shtml
Storrs, C., (December 7, 2015). CNN.com. Can light therapy treat non-seasonal depression too? http://www.cnn.com/2015/12/07/health/light-therapy-benefits/index.html