Researchers at the University of Colorado at Boulder and Brigham and Women’s Hospital in Boston examined the links between mood disorders and chronotype i.e. how early or how late a person synchronizes to the 24 hour day.
These tendencies typically manifest on a scale, ranging from morning larks who like to wake up early and go to sleep early and night owls – who prefer the opposite routine.
Whichever end of the scale you fall under is partly determined by genetics the study’s authors said – before concluding that those in the former category have a 12 to 27 per cent less chance of developing depression.
The four-year-long study was conducted using the data from 32,470 female nurses – which was extracted from the Nurses’ Health Study survey that nurses complete biannually.
Participants had an average age of 55.
The study found that those who woke up later were more likely to be depressed – even when other factors likely to put them at risk were accounted for – such as living alone – smoking and being single.