Age-Related Changes in Circadian Rhythms and Their Effects on Cognition and Psychological Well-Being: A Literature Review

Introduction: Circadian rhythms, the internal “clocks” that control a variety of physiological processes, have been found to change considerably throughout one’s lifetime. Young adults tend to be more “evening” people, while older adults tend to be more “morning” people due to age-related changes in their sleep-wake cycles. This review aims to discuss the corresponding physiological and psychological changes that occur due to the changing circadian rhythms that come with age. Methods: A literature search was conducted using the databases PubMed, PsycINFO, and AgeLine. Keywords included variations of “circadian rhythms”, “aging”, “chronotype”, “cognition”, “depression”, “mood”, “bipolar disorder”, and “anxiety”. Studies were selected and findings regarding the physiological and psychological changes due to circadian rhythms and aging were reviewed. Results: Research shows that age-related disruptions in circadian rhythms are associated with cognitive and psychological decline. Diminished sleep quality is associated with older age, due to the aforementioned underlying dysregulated circadian rhythms. Sleep deprivation is associated with increased levels of fatigue, stress, and overall mood disturbances. Moreover, circadian rhythm abnormalities associated with old age are related to greater mood disturbances, depression, and anxiety. Discussion: Poor sleep and older age are important factors that can negatively affect one’s mood and emotional well-being. It is imperative that healthcare providers consider these factors when consulting and treating patients. Populations such as shift workers have been found to have impaired levels of alertness, mood, memory, and cognitive performance due to their dysregulated circadian rhythms. Furthermore, time of day plays a crucial role in the educational success of children and adolescents. Young individuals with an evening chronotype are put at a disadvantage for early school start times due to their opposing optimal times of performance. Conclusion: Circadian rhythm dysfunction that is commonly associated with aging has the potential to contribute to adverse outcomes in human health, including cognitive deficits and pathological conditions. Future research efforts should concentrate on further clarifying the relationship between changing circadian rhythms and its impact on psychological well-being.