Sleeping with the lights or television on increases the risk of depression, according to a study by Ohio State University (USA) presented at the latest annual meeting of the American Neuroscience Society in San Diego.
In their experiments, researcher Rand Nelson and his colleagues worked with 16 hamsters, of which half slept in absolute darkness while the rest were exposed each night to a level of light equivalent to that produced by the brightness of a television on in a room. in the dark (5 lux). Eight weeks later, the animals that never slept in the dark had had their mood changed, developing depression . When the researchers examined their brains they found that in the hippocampus they observed that they had a lower density of villi (dendritic spines) in neurons than those who slept without light, which implies that communication between their nerve cells would have been reduced. According to Nelson, the results suggest that the optimal level of light that the mammalian brain needs to rest is surprisingly low .
Researchers associate the effects of light exposure to a hormone called melatonin , which is produced when the body detects darkness. Among other things, melatonin regulates the circadian rhythm, helps us fall asleep and acts as an antioxidant. If there is too much ambient light, the body could produce inadequate amounts of melatonin.
