Light work

摘要

Northern Finland in January isn't a sunny place. The residents of Oulu, a small port town some 350 miles north of Helsinki, look forward to the winter snows because they brighten the place up. And, not surprisingly many of them spend much of the winter down in the dumps. Seasonal-affective disorder (SAD) is, of course, a recognised condition. As many as 25 per cent of people living in non-tropical latitudes are believed to suffer from a low mood when there is a shortage of natural light - interestingly the condition is as prevalent at the latitude of Rome as it is in more northerly regions.