Seasonal Affective Disorder (SAD): The Winter Blues are Real

Canada can be a beautiful place to live as we get to enjoy all that each season has to offer: the flowers in the Spring, the beaches in the Summer, the magnificent colour changes of the trees in the Fall and even the many outdoor activities such as skiing, skating and tobogganing in the Winter. But there’s no denying that Winter days can also be dark, short and cold, which can place an extra strain on our mental health. And this season is undoubtedly more challenging as a result of Covid-19 and the associated isolation. So, it is even more important to be proactive when it comes to seasonal affective disorder.

Seasonal Affective Disorder, also known as “SAD”, is a recognized mood disorder that occurs cyclically each year. There are many reasons that lower mood can occur with shorter days, but the main factor seems to be related to less UV light exposure. UV light from the sun is important for many reasons but these seem to be the big ones:

• Vitamin D: we need UV rays to naturally create vitamin D in our skin. As Canadians, spending almost half of the year indoors can lead to a predictable drop in vitamin D levels each Fall and Winter season. Ask your MD or ND to have your vitamin levels tested or, at the very least, consider supplementing with 1000 IU of vitamin D per day throughout the year.

• Serotonin: serotonin is our brain’s “happy chemical” (often prescription medications are designed to increase levels of this compound). UV light is thought to increase the release of serotonin in our brains and also improve the binding to receptors.

• Melatonin: you’ve probably heard of this naturally produced chemical in our brains that helps to regulate sleep. It turns out it is also important as an anti-inflammatory hormone and it has been shown to improve skin health, gastrointestinal function and even migraines. Interestingly, melatonin is made from serotonin. This means that with less light exposure, we are blocking both pathways leading us to lower mood, less melatonin and less sleep.

So, what can we do about Seasonal Affective Disorder?

If you suffer from lower mood in the Fall and Winter months, firstly speak with a healthcare practitioner to discuss your options. Counselling can provide much needed support and there is evidence that both vitamin D and melatonin supplementation, if indicated and appropriately used, can provide improvements in SAD. Other herbal extracts such as St John’s wort may also be helpful – but should be managed by a healthcare practitioner as it can interact with various prescription medications and there is quite a range of quality when it comes to herbal extracts.

Finally, seeing as part of the mechanism behind SAD is the reduction of UV light exposure, it only stands to reason that additional light exposure may curb the feelings of low mood. Indeed, there is evidence to show that “light therapy” may help SAD symptoms and some individuals do swear by this therapy (light exposure first thing in the morning for ~30 minutes). In fact, one meta-analysis found that light therapy is equally as effective as the prescription medication fluoxetine for treating SAD. Trials seem to find that higher intensity light therapy (3000 lux daily) is better than dimmer light therapy.

In Health,

Dr. Colin