In the largest ever genetic study of circadian rest-activity cycles in humans, scientists at the University of Glasgow, supported by data from the NIHR oxford Biomedical Research Centre (BRC), have identified a possible genetic link between circadian disruption and mood disorders.
The new findings, published on 15 August in EBioMedicine, follow research published earlier this year in The Lancet Psychiatry which found that disrupted circadian rhythms were associated with increased risk of mood disorders, including major depression and bipolar disorder.
Circadian rhythms are regular 24-hour variations in behaviour and activity that control many aspects of our lives, from hormone levels to sleeping and eating habits. Circadian rhythms, which also occur in plants and animals, are fundamental for maintaining health in humans, particularly mental health and wellbeing.
The findings of this new study identified two areas of the human genome that may contain genetic variants that increase risk of disruption to rest-activity cycles.
The researchers found that one of these areas contained the gene Neurofascin, which binds to the protein product of a well-known candidate gene for bipolar disorder (Ankyrin G), suggesting a direct biological link between circadian disruption and severe mood disorder. Genetic loading for circadian disruption was also significantly associated with mood instability.
The team included Aiden Doherty, of the Oxford BRC’s Clinical Informatics and Big Data Theme, whose role involved deriving measures of activity from wrist-worn sensors distributed to over 100,000 UK Biobank participants. The BRC also provided support on the genetic analysis.