The study — which is the largest on this topic done to date with more than 90,000 participants — found that disruptions to the body's clocks were associated with a higher risk for mental health conditions, including depression and bipolar disorder. However, the researchers cautioned that the study found only an association between the biological clock and these conditions; it didn't prove cause and effect. [9 DIY Ways to Improve Your Mental Health]
The body's so-called master clock lies in an area of the brain called the suprachiasmatic nucleus. Using light cues from the sun, the master clock can figure out what time it is and relay that information to the "peripheral clocks" found throughout the body. Indeed, most cells in our body have a cluster of proteins that rotate on and off of each other to keep time throughout the day on a near-24-hour rhythm.
But factors like artificial light, night shifts, aging, certain diseases and traveling across time zones can throw this delicately tuned system into shambles. And that can lead to adverse effects (think that hazy feeling you get when you've traveled across the world).
In the study, which was published today (May 15) in the journal The Lancet, participants were recruited from the UK Biobank, a large project that took vitals and other health information from around 500,000 adults in the United Kingdom for future analysis and studies. From 2013 and 2016, more than 90,000 of these individuals were asked to wear accelerometers on their wrists that measured their movement for one week. In addition, the participants completed mental health questionnaires.