Maintaining a stable circadian rhythm in middle age is crucial for mental health, according to a study by the Institute of Health and Welfare (THL). The research, which monitored individuals’ diurnal rhythms over a ten-year period, found that those with a stable evening circadian rhythm experienced more instances of insufficient sleep, mental stress, and depressive symptoms. This group also exhibited diurnal fatigue, indicating a shift in their sleep pattern between weekdays and weekends.
Interestingly, making a moderate adjustment to focus more on morning activities helped reduce psychological symptoms in individuals with evening-oriented circadian rhythms. The study revealed that between the ages of 42 and 52, the individual circadian rhythm tends to remain fairly constant, with only subtle changes in morning and evening activity observed in most cases.
Surprisingly, less than one percent of participants reported a significant shift from a strong evening to a strong morning preference or vice versa. Conversely, around 60 percent noted no significant change in their circadian rhythm over the study period. The findings highlight the innate nature of the circadian rhythm and the rarity of major changes in this characteristic during middle age.
Docent Ilona Merikanto of THL emphasized the importance of understanding the connection between circadian rhythm stability or changes and mental health. While this relationship has been minimally explored, the study sheds light on the significance of maintaining a consistent circadian rhythm for overall well-being in middle-aged individuals.
