Can the amount of sun you’re exposed to really affect your emotional wellness? Many people think so. Scandinavians who live in the north go to great lengths to get more sun in their lives during the dark winter months. In the town of Rjukan in Norway, a man called Martin Andersen went as far as building an array of giant mirrors to reflect what available sun there was back into the town.
The idea that sunlight can affect our mental health goes back to ancient times. Written around 300BC, ‘The Yellow Emperor’s Classic of Medicine’, describes how seasons affect mood, suggesting that, during winter, one should ‘retire early and get up with the sunrise’. The French physician, Philippe Pinel, writing in 1806, notes a ‘mental deterioration’ in his psychiatric patients when winter sets in.
Dark months, dark moods
Today, this is commonly called Seasonal Affective Disorder (SAD). Most psychiatrists recognise it as a subclass of generalised depression, reported by 10% to 20% of people with depression and 15% to 22% of those with bipolar disorder. Even healthy people say they feel low during winter.
But why should this happen? There are several theories, mostly relating to the circadian clock, the biological 24 hour mechanism that regulates hunger and sleep. One idea is that people’s eyes are less sensitive to light and when light levels fall, the body struggles to maintain the circadian rhythm. Daniel Kripke, a professor of psychiatry at the University of California, proposes that levels of melatonin affects a specific region of the brain called the hypothalamus, affecting the production of thyroid hormones regulating behaviour and bodily processes. High levels of melatonin suppress the production of serotonin, a neurotransmitter than affects mood.
What helps
So what can you do if long nights and short dark days affect your mood?
Make your environment brighter – Sitting next to a light box for 30 minutes per day can be as effective as an anti-depressant medication.
Exercise – A study from Harvard University suggests walking briskly for 35 minutes each day, five times a week.
Music – Other studies show that listening to upbeat music improves mood considerably.
Go outside – Just spending time outside can improve focus, reduce symptoms of SAD, and lower stress.