Circadian Influences on Mood and Behavior

Circadian rhythms are intrinsic near-24-hour cycles that orchestrate physiological, endocrine and neural processes, aligning them with the external environment. Central pacemakers in the brain coordinate peripheral clocks throughout the body, regulating sleep–wake patterns, hormone secretion and cognitive and affective functions. Variations in circadian phase and amplitude underlie individual chronotypes, which span from morning-oriented to evening-oriented preferences. Misalignment between internal rhythms and social schedules—often termed social jet lag—can precipitate mood disturbances, impaired cognition and heightened risk of psychiatric disorders. Modern lifestyles characterised by irregular schedules, nocturnal light exposure and shift work exacerbate chronodisruption, contributing to depression, anxiety and behavioural dysregulation. Advances in ambulatory monitoring and wearable technology now permit continuous assessment of key circadian markers, offering novel opportunities for personalised chronotherapies aimed at improving mental health outcomes and daytime functioning.

Research from Nature Portfolio

Objective measurement of chronotype in school-age children has revealed that those with evening-type preferences experience pronounced social jet lag, delayed sleep timing and attenuated temperature rhythm amplitude. These alterations correlate with higher body mass indices, adverse metabolic profiles and shifts in light exposure, underscoring a link between circadian misalignment and cardiometabolic risk even in paediatric populations. Separately, a multi-variable algorithm combining wrist temperature, activity and body position has been employed to distinguish young from aged individuals with high accuracy. This integrative index captures age-related changes in circadian robustness and offers a minimally invasive tool to identify chronodisruption, with potential applications for ageing research and chronotherapeutic interventions.

Circadian Influences on Mood and Behavior publication trend

The graph below shows the total number of articles in circadian influences on mood and behavior across all publications each year (not limited to Nature Index journals).

Technical terms

Circadian rhythm: Endogenous near-24-hour cycle governing physiological and behavioural processes, synchronised by environmental cues.

Chronotype: Individual predisposition towards morningness or eveningness in activity and sleep timing.

Social jet lag: Misalignment between an individual’s internal circadian timing and social or work schedules, often resulting in sleep debt.

Acrophase: The time point at which a rhythmic biological variable reaches its peak within a circadian cycle.

Amplitude: The magnitude of oscillation in a circadian variable, reflecting rhythm robustness and consistency.

References

1. Evening types have social jet lag and metabolic alterations in school-age children. Scientific Reports (2020).
2. A New Integrated Variable Based on Thermometry, Actimetry and Body Position (TAP) to Evaluate Circadian System Status in Humans. PLOS Computational Biology (2010).
3. Unraveling the interplay of circadian rhythm and sleep deprivation on mood: A Real-World Study on first-year physicians.. PLOS Digital Health (2024).
4. The rhythm of mental health: the relationship of chronotype with psychiatric trait dimensions and diurnal variation in psychiatric symptoms. Translational Psychiatry (2024).
5. The Mind After Midnight: Nocturnal Wakefulness, Behavioral Dysregulation, and Psychopathology. Frontiers in Network Physiology (2022).