Researchers from Ohio State University found that lack of darkness during sleeping hours can cause changes to the brain and depressive symptoms, the Daily Mail reported.
Leaving the television on while you sleep can be enough to trigger the effect, scientists said.
In the research, hamsters were exposed to dim light at night for four weeks. The amount of lighting was equivalent to having a TV on in a darkened room.
Behavioural tests showed that hamsters exposed to light at night lacked energy and motivation.
They showed depressive symptoms, such as having less interest in sugary water which they normally enjoy.
Within two weeks of returning to a standard light-dark cycle, the hamsters appeared to have made a full recovery.
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The findings, published in the journal Molecular Psychiatry, point to a link with rising rates of depression in humans over the past 50 years.
"The results we found in hamsters are consistent with what we know about depression in humans," said neuroscientist Tracy Bedrosian.
"The good news is that people who stay up late in front of the television and computer may be able to undo some of the harmful effects just by going back to a regular light-dark cycle and minimising their exposure to artificial light at night. That's what the results we found in hamsters would suggest," she was quoted by the paper as saying.