KUWAIT CITY, Oct 22: A new study shows consistently getting less than five hours of sleep each night may increase the risk of depression.

“Using genetic susceptibility to the disease, we determined that sleep likely precedes symptoms of depression, rather than the other way around,” said lead author Odessa Hamilton.

The researchers used genetic and health data from 7,146 people who were in their 60s on average. The analysis was based on people's genetic traits, rather than how long they actually slept each night. Over the past few years, sleep academics have found that DNA abnormalities are linked to how much people sleep.

For decades, researchers have studied sleep difficulties as a side effect of poor mental health. But an analysis of 7,000 participants has now led scientists to say that poor sleep likely “precedes symptoms of depression,” reports Al-Rai daily. 

University College London experts said data indicates that people who get less than five hours a night are more likely to suffer.

The results showed that people who were genetically predisposed to sleeping less than five hours were 2.5 times more likely to develop symptoms of depression over the next four to 12 years.

While adults need between seven and nine hours of sleep, children need between nine and 13 hours.