Study reveals night light impact

Thursday 26th July 2012

Exposure to light at night has long been known as an inhibitor to good quality sleep, but findings from a new study suggest that it may also be a contributory factor to depression.

The study at Ohio State University, recently published, involved a series of tests on hamsters and ran for a period of months. During the first eight weeks of the research, some of the hamsters were exposed to sixteen hours of light that replicated normal daylight (150 lux) followed by a reduced light environment (5 lux) equivalent to a TV in a darkened room, while others experienced a ‘standard’ light/dark cycle of sixteen hours light and eight hours dark.

Following the eight week introduction both hamster groups were put onto the standard light/dark cycle, and their behaviour was tested at weekly intervals for a period of four weeks.

It was found that the hamsters that had been in the artificial light environment showed distinct signs of depressive tendencies compared to the hamsters from the standard light/dark cycle. Notably however, these tendencies lessened and were not in evidence by the second week of being taken out of the artificial light environment, suggesting that the negative effects are temporary.

Tags: light sleep depression

Category: Sleep Research

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