(Colin Davidson, Claire Hutchinson/Medical X-Press) — Have you ever noted that you sleep more in the winter months? Or eat more carbs or have low energy? If you do, then you might be one of the around 6% of the higher latitude populations with seasonal affective disorder (SAD).
If you’ve searched the internet for tips on how to fight the winter blues you’ve probably been advised to buy a therapy lamp. So you may be wondering what research says about whether they are effective and how they work.
Before we examine the evidence for light therapy it’s important to understand why mood might be affected by sunlight. Vitamin D is produced when your skin is exposed to sunlight and some scientists believe there is a link between depression and low vitamin D levels.
Studies have found about 10% of the population of the far north, for example in Alaska and Finland, experience SAD. Interestingly, Icelanders, who also live in these very northern latitudes, do not appear to suffer so much from SAD. This might be because of their fish-packed diet, which is rich in vitamin D. (…)