People often joke about the winter blues, but a lack of sunlight is actually considered to be the cause of a type of depression known as Seasonal Affective Disorder (SAD). It was first recognised as a mood disorder in the 1980s, when Dr Rosenthal published a paper investigating the possibility that people feel more depressed in winter, due to the lack of light. His paper found that light therapy improved his subjects’ moods, suggesting that SAD is indeed triggered by a lack of sunlight.
However, does the modern life also cause SAD? The majority of adults work at least 40 hours a week, mostly during the sunniest parts of the day. If you spend the hours between dawn and dusk in a dingy office, is it fair to say that the lack of sunlight at work causes depression?
Since Rosenthal’s study, SAD has become more and more recognised as a disorder with real consequences to an individual’s quality of life. Scientists aren’t sure of the reasons behind it, but some theorise that too little sunlight causes depression in humans because we originally evolved in the savannahs of Africa. Therefore, we as a species are adapted to be exposed to sunlight all year round. Without a daily dose of sunlight, the human body can become too low on vitamin D. Vitamin D is made by the body as a reaction to sunlight, and a lack of it can be a contributing factor to depression.
However, in Norway people have existed for years with low daylight hours during the winter months and the infamous midnight sun during the summer yet is there any evidence to suggest that people living in this region of the world are more depressed than others?
It is possible that lack of sunlight can cause depression but perhaps there are other factors involved too such as poor lighting or fluorescent lighting, which is actually shown to cause stress and consequently can lead on to depression.
So, what can you do if you think you are vulnerable to depression caused by a lack of sunlight? Well, there are a variety of things you can do, before you quit your job and become a dog walker! There are multiple treatments available for SAD, including the light therapy of the 1980s, anti-depressants and vitamin D supplements – the latter of which the Norwegians are very good at eating specific foods, rich in them to help counteract the issue of lack of light.