Just in time for the winter solstice, scientists may have figured out how short days can lead to dark moods. Two recent studies suggest the culprit is a brain circuit that connects special light-sensing cells in the retina with brain areas that affect whether you are happy or sad.
Together, the studies offer a strong argument that seasonal mood changes, which affect about 1 in 5 people, have a biological cause. The research also adds to the evidence that support light therapy as an appropriate treatment.
This article and audio can be found on NPR’s website, here.