A study led by the University of Glasgow, UK, has found that disrupted circadian rhythm increases the risk of an individual developing mood disorders such as depression and bipolar disorder.
Published in The Lancet Psychiatry, the new study found that circadian rhythm disruption was associated with an increased risk of mood disorders, as well as lower subjective wellbeing, higher neuroticism and greater mood instability.
A circadian rhythm is a variation in the physiology and behaviour of an individual that recurs every 24 hours, such as the sleep-wake cycle and daily patterns of hormone release. It’s important to overall mental health and wellbeing.
Analysing rest-activity rhythms
Researchers used the activity data of 91,105 participants in the UK Biobank cohort to obtain a measurement of daily rest-activity rhythms, known as relative amplitude.
Those with lower amplitude were found to be at greater risk of adverse mental health outcomes, regardless of demographic and educational factors.
Also found was that lower amplitude was associated with low subjective ratings of happiness and health satisfaction, with higher risk of reporting loneliness and with slower reaction time.
Lead author on the study Dr Laura Lyall said: “In the largest such study ever conducted, we found a robust association between disruption of circadian rhythms and mood disorders. Previous studies have identified associations between disrupted circadian rhythms and poor mental health, but these were on relatively small samples.”
What is the next step?
Professor Daniel Smith, professor of psychiatry and senior author, said: “This is an important study demonstrating a robust association between disrupted circadian rhythmicity and mood disorders.
“The next step will be to identify the mechanisms by which genetic and environmental causes of circadian disruption interact to increase an individual’s risk of depression and bipolar disorder.
“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.”
Source: University of Glasgow