Researchers studied whether our sleep-wake cycle affects mental health especially whether disturbance in this cycle is a biological risk factor underlying bipolar disorder. Bipolar disorder is a mental health condition that causes extreme mood swings that include emotional highs (mania or hypomania) and lows (depression).
The circadian rhythm is the 24-hour internal clock in our brain that regulates cycles of wakefulness and sleepiness by responding to light changes in our environment. Our physiology and behaviour are shaped by the Earth's rotation around its axis.
Bipolar disorders, 2022