It’s getting darker and darker at the moment, and I’m not just talking about the economy. As the seasonal cycle goes on, and the nights set in earlier, and the weather gets gloomier, it’s only natural that some people might get a little bit down. Maybe that’s why lamps targeted at sufferers of SAD are selling like hot cakes.

SAD stands for Seasonal Affective Disorder, and it’s a psychological disorder caused by a lack of sunlight. Symptoms include lethargy, low mood and anxiety. SAD lamps produce a more sunlight-like output than a normal lamp, and so they’re supposed to help your mood.