Obviously this is purely anecdotal. I have the same habits as the author with respect to light exposure regulation. I live in England and take an hour walk every day around noon regardless of weather. At night I avoid computers for about two hours before bedtime and although I do not read paper books (I should find my local library...) I set a screen filter on my amoled phablet and often invert the text so it shows white on black. I exclusively use a red LED at night for lighting. This all helps a lot, bit the thing that seems most striking is vitamin D. Sometimes I feel down and realize I haven&#x27;t had exposure to many sources for a while. A few days of heavy doses and my mood improves. I don&#x27;t take it orally all the time, just as I imagine I need it. The effect is sublte but it would be cool if someone could figure out how to quanitfy.<p>As a result of all this care about light I haven&#x27;t had a SAD winter for most of a decade. I feel &quot;cured&quot; of it enough that spending time in even more northerly places in the winter does not trigger unpleasant depression. That said, us northern peoples should slow down in the winter. Thousands of years of selection has driven this home, and it is nothing to be upset about. We will make up for the slowness of the winter in the long days of summer.