Seasonal Affective Disorder is a particular type of depression that is linked to those months of the year where natural daylight is significantly reduced. In the UK at least, this is most commonplace where the clocks revert back an hour from British Summer Time to Greenwich Mean Time; October to March.
I've been watching a lot of Christmas films the past few weeks. Many of them appalling TV movies that wouldn't have a hope of making it into the cinema. But they all have one key thing in common.