Women who wake up early as they get older are less likely to develop depression than those who love a lie-in, according to research.
Scientists say exposure to daylight affects a person’s risk of becoming depressed, and women who wake up early have a 12 to 27 per cent lower chance.
A study of more than 32,000 women with an average age of 55 found those who describe themselves as evening or intermediate types are more likely to end up with the mental illness.
It is not a curse, however, and the scientists say people who like to sleep late can help reduce their risk by getting up earlier and seeing more daylight.
The research also found night owls are less likely to be married and more likely to live alone, be smokers, and have erratic sleep patterns – all of which could increase depression risk.
But the link between sleeping preference and depression still remains even when those factors are accounted for.
The research was done by scientists at the University of Colorado Boulder, and Brigham and Women’s Hospital in Boston.
It is the largest ever study of its kind and studied the effect of a woman’s chronotype – what times a person prefers to sleep and wake up – on her risk of depression.
Researchers claim chronotype affects depression risk even when exposure to daylight and working schedules are taken out of the equation.
Depression thought to affect one in ten people
‘There might be an effect of chronotype on depression risk that is not driven by environmental and lifestyle factors,’ said lead study author and director of the university’s sleep lab, Céline Vetter.
Depression is a fairly common mental health problem which can affect anyone at any age.
Around one in ten people are thought to experience it at some point in their life, and it can cause people to feel upset and to lose interest in things they used to enjoy.
While people with the condition may feel despair, there are therapies which can help to treat it, including medication and counselling.
People can turn themselves into early risers
Whether someone is an early bird, intermediate type or a night owl is partly determined by genetics, but late risers are not doomed, the scientists say.
‘When and how much light you get also influences chronotype, and light exposure also influences depression risk,’ Dr Vetter added.
‘Yes, chronotype is relevant when it comes to depression but it is a small effect. Being an early type seems to beneficial, and you can influence how early you are.’
She adds trying to get enough sleep, exercise, spending time outdoors, dimming the lights at night, and getting as much daylight as possible are all helpful.
How the research was done
The researchers studied 32,470 female nurses from the Nurses’ Health Study, which asks participants to fill out health surveys every two years.
At the beginning none of the participants had depression.
The women were asked to describe their own chronotype, and 37 per cent described themselves as early types, 53 per cent were intermediate types, and 10 per cent were evening types.
Known risk factors for depression including body weight, physical activity, chronic disease, sleep duration, and night shift work were also considered.
Even when lifestyle factors were accounted for, early risers still had a 12 to 27 per cent lower risk of being depressed than intermediate types.
Late types had a six per cent higher risk than intermediate types, but that increase was not considered big enough to be important.
The findings were published in the Journal of Psychiatric Research.