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CLEVELAND (CBS Cleveland) — Watching television show re-runs or viral videos to put yourself to sleep may be depressing to many, and now a group of neuroscientists say research is proving just that.
Researchers from Ohio State University Medical Center say that the rise in exposure to artificial light – specifically that of computers and TV screens – at night in the last 50 years has coincided with rising rates of depression, especially acute with women.
The study found that hamsters with chronic exposure to dim light for eight hours each night showed signs of depression within just a few weeks. This was tested against another group of hamsters who had total darkness for at least eight hours. The dim-light hamsters had reduced physical activity compared with hamsters living in normal light-to-dark conditions and less interest in one of their favorite treats: sugar water. They also had greater signs of distress when placed in water and changes to their brain functions that mirror that of depressed humans.
“The results we found in hamsters are consistent with what we know about depression in humans,” Tracy Bedrosian, the first author on the new study, told CNN. “The advent of electrical lighting permitted humans to stray from natural day-night cycles and it’s disturbing biological, natural rhythms.”
This research follows up an American Medical Association study that highlights the adverse health effects of nighttime lighting, which notes that artificial lights disrupt circadian rhythms and alter the body’s normal hormonal responses. The study found that the body suppresses the release of the hormone melatonin that is thought to fight tumor growth, cancers, and regulate sleep schedules as a whole. It also linked continuous dim lighting and digital nighttime lighting to obesity, diabetes and reproductive problems.
But there is hope for both human night owls and hamsters alike.
“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 minimizing their exposure to artificial light at night,” Bedrosian states in the study’s conclusions. “That’s what the results we found in hamsters would suggest.”
For the hamsters, their depressive symptoms faded after they returned to a schedule that included eight full hours of total darkness per day. The presence of dim, electronic lights was insufficient for the body’s natural need for darkness.
But for many city dwellers or Netflix hounds this may be easier said than done. Light pollution can come from TV and computer screens, as well as other electronic displays and ambient sources such as streetlights, passing traffic and neighboring buildings, in addition to overhead lighting with the home.
Studies of the hamsters’ brains revealed that a protein may play a key role in how exposure to light at night leads to depression, the researchers said. But there is a lot more research needed to truly link the hamster’s behavior with that of humans.