Seasonal Affective Disorder (SAD) is a form of clinical depression that comes and goes in a seasonal pattern. It’s also referred to as “winter depression,” because that’s usually the time when symptoms become more pronounced and noticeable. The lack of sunlight during the winter months is thought to contribute to symptoms of SAD including loss of energy, mild depression, oversleeping, overeating and carbohydrate cravings. Many people with SAD have a delayed circadian rhythm — they fall asleep and wake up too late.
According to Dr. Robert Levitan, a professor at the University of Toronto’s Faculty of Medicine 3 to 5 percent of Canadians experience SAD1. As many as 20 percent may have a mild form of it that starts when days get shorter and colder.
“A common explanation for SAD is that it’s a form of hibernation, left over from our cave-dwelling days. This explains the carb cravings, overeating and feeling of lethargy — all help to conserve energy. The theory doesn’t explain why depression occurs, but it’s possible that depression is the result of the hibernation itself — lack of socialization and exercise, and increased junk food,” Dr. Levitan writes.
“Increased junk food”, “carbohydrate craving”, “weight goss” are typically cited a central to the symptom picture of SAD. Patients with SAD often have higher levels of melatonin and decreased levels of serotonin. Melatonin is implicated since it is produced at night and because longer hours of darkness can lead to greater production of melatonin. A drop in levels of serotonin play a role because reduced sunlight can cause serotonin levels to fall2.
Exposure to bright light daily via a special (full-spectrum) light source, also known as ‘light therapy’, is the treatment method most often recommended for patients whose SAD symptoms are severe enough to affect their daily lives. Most patients with mild-to-moderate symptoms respond to light therapy from a light box at 2500 lux 2h/day or 10,000 lux one hour/day, within 1-2 weeks where about 50% achieve complete remission.
Also, a ‘dawn simulator’ can be employed to help wake a person up in the morning and get that immediate exposure to light so as to shut down brain melatonin production and fire up serotonin production3.
Two natural health products are widely recommended to further attenuate SAD symptoms. One is Vitamin D. The ‘sunshine vitamin’ so, of course. Check blood levels of 25-OH vitamin D. At this latitude and this time of year, Vitamin D levels decline and restoring it to normal range reduces the expression of SAD symptoms.
The second family of supplements that are useful is those that sustain normal serotonin levels. Dr. Levitan favours using the amino acid l-tryptophan. Dr. Andrew Weil likes St. John’s Wort4. Others use 5-Hydroxytryptophan (5- HTP). Serotonergic prescription medicaments are commonly used alternatively including SSRIs like paroxetine (Paxil), sertraline (Zoloft), fluoxetine (Prozac, Sarafem) and venlafaxine (Effexor) or an extended-release version of the antidepressant bupropion (Wellbutrin XL).
Two other commonsensical things may also be recommended. One is to get outside in the sun and exercise. The exposure – despite the cold – to natural sunlight combined with physical exercise is widely reported to be beneficial.
The other simple injunction is to ease up on junk carbohydrates and eat more protein and essential fatty acid rich foods, that are seasonal in any case.
The Centre for Addiction and Mental Health (CAMH) in Toronto and its teaching hospital have long specialized in treating SAD and may be a good resource, if needed.
1. SAD? Head toward the light, advises U of T expert; UofT News, https://www.utoronto.ca/news/feeling- sad-head-toward-light-advises-u-t-expert
2. Beat the Winter Blues! Seasonal Affective Disorder; Melissa McCarty, ND; http://www.naturopathic.org/ content.asp?contentid=262
3. Sunrise Light Alarm Clocks; https:// wakeuptothesunriselight.com/
4. Seasonal Affective Disorder (SAD); httpFeelings://www.drweil. com/health-wellness/body-mind-spirit/mental-health/ seasonal-affective-disorder-sad/