During the darkest periods of the polar night, Tromsø only receives two to three hours of indirect sunlight, shining into the sky from below the horizon. Yet its inhabitants do not show the kind of wintertime depression you might expect of a city cast in darkness. One study by May Trude Johnsen at the University of Tromsø found that the citizens’ wellbeing barely changed across the year. Their sleep was a bit more disturbed without the daily rhythm of the rising and setting sun, but they reported no increase in mental distress during the winter… More here.
Some very good advice here.