Not many of us will relish the contracted days and long nights the winter months bring. However, for sufferers of seasonal affective disorder (SAD), the darkened skies that accompany this time of year can often be viewed with particular dread. SAD, a depressive condition triggered by low levels of sunlight, is thought to affect more than a million Britons, while a more muted version of the condition, known as sub-syndromal SAD, afflicts millions more. For sufferers of these conditions, lack of sunlight can sometimes go way beyond low mood and melancholy; with fatigue, unrefreshing sleep, carbohydrate cravings, weight gain and loss of libido being common side issues too. For many, it seems that this time of year can herald a significant downturn in well-being and a darkening of mood.
SAD and sub-syndromal SAD are believed to be the result of alterations in brain chemistry related to less than optimal levels of sunlight exposure. No wonder then that studies have shown that increasing light exposure is very often effective in lifting mood. The science suggests that light at a brightness of 2500 lux (lux is the standard unit of measurement for brightness) has the capacity to brighten our outlook, even within a few days. The light intensity in a typical house is 100 lux or less, and workplace illumination is generally not much better at about 300 – 500 lux. What this means is that getting up and coming home in the dark, as many of us do in the depths of winter, puts us at very real risk of running into problems with SAD or sub-syndromal SAD.
Getting out and about in the wintertime offers a ray of hope for those prone to light-related depression. Even the dullest of days offers about 2000 lux of light, with brightness going up to 10,000 lux or so when the sun shines. Increasing light exposure has been shown to help not just mood, but other features of SAD and sub-syndromal SAD too. A recent study found that light treatment significantly decreased depression ratings and improved mood, energy, alertness and productivity scores in a typical workplace setting. Another study found that bright light improves vitality and mood among individuals working indoors in the wintertime, even in those not suffering from SAD.
Another strategy that is useful for uplifting mood in the winter is exercise. A recent study found that exercise alone was as effective as bright light in relieving depressive symptoms. Other studies have found that exercise is significantly more effective at alleviating other symptoms of SAD and sub-syndromal SAD when combined with bright-light exposure. The conclusion drawn from these studies is that while either exercise or light can improve mood, well-being and overall quality of life, they are most effective when applied together.
From a dietary perspective, it may help those with SAD or sub-syndromal SAD to eat plenty of oily fish such as salmon, trout, and mackerel, as the consumption of the omega-3 fats present in these fish seems to balance brain chemistry and protect against depression. Another natural remedy to consider is the medicinal herb Hypericum perforatum (St John’s Wort), which studies suggest can be effective in combating the symptoms of SAD. For those prone to the winter blues, the good news is that relatively simple lifestyle adjustments can do much to bring the sunshine back into their lives.