GOOD sleep is key to warding off the blues, researchers say.
Regularly sleeping less than five hours a night was found to raise the risk of depression.
GettyGood sleep wards off depression, according to researchers at UCL[/caption]
But experts at University College London also found a link between sleeping too long and feeling blue.
People kipping for more than nine hours were 1.5 times more likely to have depression than those getting seven hours of shut-eye.
Dr Odessa Hamilton of UCL said: “We determined that short sleep likely precedes depressive symptoms, rather than the other way around.”
Researchers used genetic and health data from 7,146 people in England to see if they were prone to depression or short sleep.
Study participants – who had an average age of 65 – got about seven hours’ sleep a night.
About 10 per cent snoozed less than five hours nightly at the start of the research, rising to 15 per cent by the end.
Those suffering from depression rose from 8.75 to 11.5 per cent.
Professor Andrew Steptoe said: “Poor sleep and depression increase with age, and with the population ageing worldwide there is a growing need to better understand the connection between depression and a lack of sleep.”
Earlier research has shown that sleep duration and depression are both partly passed down from one generation to the next.
The NHS recommends between seven and nine hours’ sleep a night.