In research that may have implications for depression in humans, researchers at Ohio State find that hamsters exposed to blue and white light rather than red light while sleeping exhibited depressed behavior. The authors suggest limiting exposure to TVs and computer screens at night. The study was published in the Journal of Neuroscience.
Bedrosian, T., Vaughn, C., Galan, A., Daye, G., Weil, Z., Nelson, R.; Nocturnal Light Exposure Impairs Affective Responses in a Wavelength-Dependent Manner. Journal of Neuroscience. Online August 7, 2013
Of further Interest:
Study: Light Color Affects Mood (Voice of America)