The circadian system coordinates key physiological processes such as our sleep cycles, our metabolic systems and it is central to the maintenance of our daily cycles and sense of wellbeing. It is regulated by common environmental factors, such as the timing, intensity and spectrum of light exposure, and can be measured objectively (i.e., motor activity, sleep, core body temperature, eating behaviour, melatonin, and cognitive performance) and also subjectively (e.g., energy, somatic symptoms, and mood).
The term circadian disruption, or dysregulation, is accompanied by large shifts in the 24-hour patterns of the sleep-wake cycle, typically due to external (e.g., shift work or jet lag) or internal factors (e.g., hormone levels, blindness). It can be defined as a disturbance of biological timing, which can occur at different organisational levels, ranging from molecular rhythms in individual cells to misalignment of behavioural cycles with environmental changes.
Many mood disorders are either characterized by circadian rhythm disruption or precipitated by an irregular light–dark cycle. One example is seasonal affective disorder in which mood is lower during the short-day lengths of winter compared to the long summer days.
"The circadian system coordinates key physiological components, including sleep and body’s metabolism, and is central to people’s wellbeing. We think that the disruption of the circadian system is causally linked to mood disorders and, interestingly, there are social, cultural and biological factors that shape how circadian disruption manifests in different populations around the world. In this project we will collect data also from animal studies to shed light on the mechanism behind circadian disruption and the development of depression and mania, especially in adolescents and young adults.” - Professor Andrea Cipriani. GALENOS Director.
