The color of night light directly affects a person’s mood, researchers have found. While blue light spurs depression, red light charges you for a bright, happy morning!
Use of tablets may induce depression
Computer monitors emit blue light. People who take the tablets or the mini computers to bed not only experience a lack of sleep over weeks and months but are also at higher risk of depression.
“Modern environmental lighting conditions have led to excessive exposure to light at night (LAN), and particularly to blue wavelength lights. We hypothesized that nocturnal light exposure (i.e., dim LAN) would induce depressive responses and alter neuronal structure in hamsters…” Randy Nelson, a professor of neuroscience and psychology at The Ohio State University and one of the authors of the study said.
In order to check how different colored lights impact individuals, the researchers employed hamsters.
For 4 weeks each female hamsters were exposed to nighttime conditions either with no light, dim red light, dim white lights or dim blue light.
Hamsters were then checked for depression symptoms, if any.
The researchers specifically looked at ipRGCs, the photosensitive cells in the retina. Although these cells play no role in vision, however, they detect light and send messages to the part of the brain responsible for regulating and controlling the body’s circadian clock.
Researchers found that hamsters exposed to no light did not experience depression. Following closely were the hamsters exposed to red light.
The hamsters exposed to dim white or dim blue light, however, exhibited the highest depression-like-symptoms, researchers highlighted.
“In nearly every measure we had, hamsters exposed to blue light were the worst off, followed by those exposed to white light,” said Nelson. “While total darkness was best, red light was not nearly as bad as the other wavelengths we studied.”
“Our findings suggest that if we could use red light when appropriate for night-shift workers, it may not have some of the negative effects on their health that white light does,” Nelson said.
The findings of the study are reported in The Journal of Neuroscience.