Insomnia and mood: watch out for ‘social jet lag’ – here’s why it’s important to stick to your natural rhythms

“How boring, how tedious, how boring.” The classic ending to the sketches featuring Sandra Mondaini and Raimondo Vianello springs to mind – one that highlighted the need to break the routine with something new – whilst sifting through the results of a study that leads to exactly the opposite conclusion. In later life, routine allows us to maintain the rhythms that our biological clock has established over the years. It becomes a genuine protective shield for those struggling with insomnia and (as a consequence or trigger of sleep disorders, but not limited to these) with depression and chronic pain. The importance of respecting circadian rhythms has been reaffirmed by research conducted by experts at the University of Missouri, coordinated by Eunjin Tracy, and published in the Journal of Behavioural Medicine. The study clearly shows that maintaining a consistent daily routine – in terms of waking up, mealtimes, work and time spent socialising promotes physical and mental wellbeing, to the extent that older people who pay attention to the regularity of their daily schedules experience less physical pain and fewer signs of depression, particularly if they suffer from insomnia.

The study examined the relationship between sleep difficulties and health and quality of life in 67 older adults who completed a targeted questionnaire. Just over half of them suffered from insomnia. Analysis of the results revealed a recurring pattern. Those who managed to maintain a regular routine day after day had a lower risk of pain and low mood, regardless of their sleep quality. “If we maintain regular times for waking up, eating, working or studying, interacting with others and going to bed, these temporal cues help to synchronise our internal biological clock,” comments Tracy in a university statement. In the long term, this appears to be linked to better health outcomes.” In short. Regular activities provide cues that help regulate the circadian rhythm, the body’s internal 24-hour timing system. This biological clock plays a key role in sleep, mood and many other bodily processes. “When we regulate our circadian rhythm properly, our body functions well, but if it is disrupted too much, our body does not function well,” says Tracy. And not just, it must be said, when it comes to a good night’s sleep. This is why the link between daily routine and depression must always be borne in mind. “These observations confirm once again just how important it is to maintain a regular circadian rhythm beyond sleep, bearing in mind mood as well,” comments Lino Nobili, President of the Italian Academy of Sleep Medicine (AIMS), and lecturer at the University of Genoa at the IRCCS Gaslini.

Every organ in our body has genes known as ‘clock genes’ that regulate the activity of that organ – the heart, lungs, muscles and more. These peripheral clocks are synchronised with the master clock located in the brain, the suprachiasmatic nucleus. “A disruption in the regularity of the sleep-wake cycle and our circadian rhythms, (diet, physical activity, etc.) disrupts the coordination between the peripheral clock genes and the central clock. This not only has negative effects on cognitive function, mood and pain perception, but also causes functional alterations in individual organs,” explains Nobili. “It is well known in this regard that, as in the extreme example of shift workers, there is an increased risk of various cardiovascular, metabolic and even cancer-related conditions.”

The warning that emerges is clear. And it probably applies to everyone, although as we get older, adapting to constantly changing routines becomes more difficult. If we frequently change our sleep schedules, mealtimes or other daily activities, we risk disrupting our circadian rhythm regulation system. And unfortunately, even if we don’t go out all night or have midnight dinners, even relatively small differences between weekday and weekend (as well as holiday) schedules can create what researchers often call ‘social jet lag’. ““There is a growing awareness of the concept of social jet lag – waking up and going to bed at different times at the weekend compared to weekdays – and of the disruptions it causes to our circadian rhythm, so I hope this research will help more people to consider the health benefits of a daily routine,” concludes Tracy, “. Ultimately, it is the elderly who are most at risk, as their circadian regulation system is much more fragile in terms of its ability to adapt, and they are therefore more vulnerable to these issues when their routine is disrupted. “”In fact, this also happens in children, in this case due to their greater sensitivity to the stimuli that regulate the sleep-wake cycle,” concludes Nobili. “So, in reality, this apparent monotony of regularity becomes an important ingredient in the recipe for general health, especially in older people.”