Early to bed and early to rise can keep you safe from depression
Several studies have pointed out a link between sleep and depression. A new study by researchers at the University of Colorado Boulder and the Channing Division of Network Medicine at Brigham and Women’s Hospital in Boston, has found that keeping depression at bay can be as easy as getting out of the bed early.
The study shows that middle-to-older aged women, who are naturally early to bed and early to rise, are significantly less likely to develop depression. The study was done on more than 32,000 female nurses and explored the link between chronotype, or sleep-wake preference, and mood disorders. It showed that even after accounting for environmental factors like light exposure and work schedules, chronotype appears to mildly influence depression risk.
“Our results show a modest link between chronotype and depression risk. This could be related to the overlap in genetic pathways associated with chronotype and mood,” said lead author Celine Vetter.
The researchers found that late chronotypes, or night owls, are less likely to be married, more likely to live alone and be smokers, and more likely to have erratic sleep patterns. After accounting for these factors, they found that early risers still had a 12-27% lower risk of being depressed than intermediate types. Late types had a 6% higher risk than intermediate types (this modest increase was not statistically significant).
Genetics play a role in determining whether you are an early bird, intermediate type, or night owl, with research showing 12-42% heritability. And some studies have already shown that certain genes (including PER2 and RORA), which influence when we prefer to rise and sleep also influence depression risk.
“Alternatively, when and how much light you get also influences chronotype, and light exposure also influences depression risk,” Vetter said.
Vetter stressed that while the study suggested that chronotype was an independent risk factor for depression, it did not mean night owls were doomed to be depressed. “Being an early type seems to beneficial, and you can influence how early you are” she said. “Try to get enough sleep, exercise, spend time outdoors, dim the lights at night, and try to get as much light by day as possible.”
The study is published in the Journal of Psychiatric Research.