A recent study conducted by the Institute of Health and Welfare has shown that individuals aged 42-52 have a stable circadian rhythm. This is significant for mental health in middle age, according to the study. The research monitored the diurnal rhythms of participants over a ten-year period.
The findings indicated that individuals with a stable circadian rhythm in the evenings experienced more insufficient sleep, mental stress, and depressive symptoms than others. This group also displayed diurnal fatigue, demonstrating a change in sleep patterns between weekdays and weekends. Making a moderate shift towards a morning focus reduced psychological symptoms in these individuals with evening tendencies.
The research also revealed that changes in morning and evening activity in middle-aged individuals are typically moderate. Less than one percent of participants reported a shift from a strong evening to a strong morning preference or vice versa. Nearly 60 percent did not observe any significant changes in their circadian rhythm over the ten-year study period.
THL’s Visiting Researcher, Docent of Public Health Sciences Ilona Merikanto, emphasized the innate nature of the circadian rhythm based on the study’s results. She highlighted the strong inheritance of this characteristic and the rarity of major changes among middle-aged individuals. The connection between the stability or changes in the circadian rhythm and mental health is an area that has not been extensively studied, according to THL.
