Scientists Find A Brain Circuit That Could Explain Seasonal Depression

"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."

"When these cells detect shorter days, they appear to use this pathway to send signals to the brain that can make a person feel glum or even depressed."

"'It's very likely that things like seasonal affective disorder involve this pathway,' says Jerome Sanes, a professor of neuroscience at Brown University."

"Sanes was part of a team that found evidence of the brain circuit in people. The scientists presented their research in November at the Society for Neuroscience meeting. The work hasn't been published in a peer-reviewed journal yet, but the researchers plan to submit it."

"A few weeks earlier, a different team published a study suggesting a very similar circuit in mice."