A new study published in The Lancet found an association between disrupted circadian rhythms and mental health issues like major depressive disorder and bipolar disorder. The study looked at 91,000 people and whether they had a standard circadian rhythm (active in the day, resting at night) or a disrupted one (resting in the day, active at night). Those with a disrupted circadian rhythm were 6 to 10 percent more likely to have a mental health issue diagnosis. "The study tells us the body clock is really important for mood disorders and should be given greater priority in research and in [the] way we organize societies," Daniel Smith, co-author of the study and Professor of Psychiatry at the University of Glasgow, told the BBC. You can read more about the study on BBC News or view the published study on The Lancet.