In the largest study of its type, researchers at the University of Glasgow asked more than 90,000 subjects to wear activity monitors for a week in order to monitor disruption to their biological clocks, or circadian rhythm.
Maintaining a normal body block, which means being more active in the day and sleeping at night, was found by researchers to have a positive effect on a person's mental health.
A new study by the University of Glasgow has found a disrupted 24-hour body clock, typically caused by things like checking Facebook at midnight or getting up to make a cup of tea in the middle of the night, could increase your risk of depression and bipolar disorder. Irregular sleep patterns were also associated with mood swings and increased neuroticism and feelings of loneliness and unhappiness, along with slower reaction times.
"But it's not just what you do at night", he said, "it's what you do during the day - trying to be active during the day and inactive in darkness", he told.
The findings were found to be consistent even when controlling for a number of influential factors including age, sex, lifestyle, education and body mass index, according to Smith. The clocks change how the tissues work in a daily rhythm.
'This is an important study demonstrating a robust association between disrupted circadian rhythm and mood disorders'.
To address these methodological issues, the researchers analysed activity data in 91,105 participants (aged 37-73) from the UK Biobank general population cohort to obtain an objective measure of patterns of rest and activity rhythms, known as relative amplitude.
They are also likely to feel less happy and more lonely, the study found. "I don't think it's unreasonable to say this is another piece of evidence that might suggest we should all be more mindful of our natural rhythms of activity and rest", Professor Smith explained. Circadian rhythms occur in plants, animals and throughout biology.
This is important globally because more and more people are living in urban environments that are known to increase risk of circadian disruption and, by extension, adverse mental health outcomes.
Professor Smith added: 'There are a lot of things people can do, especially during the winter, such as getting out of the house in the morning to get exposed to light and take exercise, so that by evening they are exhausted.