In the study involving Siberian hamsters (Phodopus sungorus), senior author Prof Randy Nelson from the Ohio State University, first author Dr Tracy Bedrosian of the Salk Institute, and their colleagues, found that blue light had the worst effects on mood-related measures, followed closely by white light. But hamsters exposed to red light at night had significantly less evidence of depressive-like symptoms and changes in the brain linked to depression, compared to those that experienced blue or white light.
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