Disruption of the sleep-wake cycle

Our day-night rhythm is controlled by the biological clock in the brain. When the biological clock becomes disrupted, it can lead to a significant shift in the sleep pattern. For example, a combination of being unable to fall asleep until late at night, but then being unable to wake up in the morning. Sometimes, individuals may be extreme "morning people" and fall asleep very early in the evening. In some cases, the rhythm gradually shifts later each day.

To diagnose a biological clock disorder, the day-night rhythm is mapped over several weeks. Sometimes, melatonin, the hormone of the biological clock, is also measured.

Although it is sometimes not easy, the sleep-wake rhythm can be adjusted. This is done in close collaboration between the doctors and sleep therapists in the team. A plan is created to shift the rhythm in small steps. This is often supported with light therapy, at specific times using a special lamp. Finally, melatonin is sometimes used, also according to a precise schedule. If the rhythm can be shifted, light therapy can help maintain the adjusted rhythm.