Once upon a time, group of settlers found themselves in a strange land. It was cold, dark and raining all the time. Nothing grew properly and even those few animals who wanted to live in the area were vicious and had very little to eat on.
So they decided to live there. Still, generations to come are shouting to the heavens and asking "Why, why did you do this?"
Places like Finland are not only cold and climate sucks otherwise really big time, but it's far from everywhere. And most of the year it's really dark. In northern parts on Finland (in Lapland), there are times when the sun doesn't rise. It's only 24/7 darkness. In the most northern part of Finland, the polar night lasts for 51 days.
Even in Helsinki, which is the capital of Finland and very south in Finland, the shortest day is less than 6 hours long. Imagine, if you go to work before the sun rises and work for 8 hours, you won't see any sunlight during the whole day. Unless you have windows in the office, but who has time to stare out of any windows. The only Windows you need is Windows 10.
Pixabay
SAD, Seasonal affective disorder
In Finnish it's called "Kaamosmasennus", while kaamos being the polar night - the time when sun doesn't rise. "Polar night depression" could be a very direct translation.
The symptoms are very similar to depression, but unlike with "regular depression" SAD is not primarily treated with psychotherapy and medication, but light therapy can be beneficial to people suffering from SAD. SAD is more common in countries with dark winters and far less common close to equator, as there is plenty of light around the year.
Even thought light therapy is efficient for most people affected by SAD, it is a serious illness at worst, as the symptoms include anxiety, sadness, reduction of libido, increased need for sleep, loss of happiness. At least in Finland, people living in Lapland are using more alcohol and violent crimes are more common than in most of Finland, per head of population.
By User:Mysid [Public domain], via Wikimedia Commons
Light therapy done right
High intensity light treatment is a cheap price to avoid depression symptoms. For the light treatment, it is recommended to have a high intensity lamp of 2500 to 10000 lux and be close to the light source for 30 minutes to one hour every morning. The earlier the treatment is made the more efficient it is. Distance is crucial in the light treatment, so being closer to the lamp while not staring at the light itself gives better results.
It is recommended to continue the daily treatments for 2-4 weeks and after this it is recommended to continue in cycles of 1-2 weeks without light and then with light, as it is common that the SAD symptoms will re-emerge after 1-3 weeks after light treatment has ended.
Like with regular depression, regular exercise can help to control the depression symptoms and with SAD it can reduce the need of light treatment.
In the end, who knows if suicide rates in northern countries would be lower if people would use more light treatment instead of trying to cure themselves with alcohol.
Read more:
https://www.mayoclinic.org/diseases-conditions/seasonal-affective-disorder/symptoms-causes/syc-20364651
https://teens.webmd.com/seasonal-affective-disorder#1
SAD and light treatment instructions source (in Finnish):
http://www.terveyskirjasto.fi/terveyskirjasto/tk.koti?p_artikkeli=dlk00377