Latest article: Sleep, circadian rhythm disturbance, and cognitive disorders: Exploring the connection

Sleep is not just a passive state of rest; it is a complex and vital process orchestrated by our circadian rhythm. Suboptimal sleep affects 42% of Australian adults, with a higher prevalence among females, middle-aged individuals, and those of low socioeconomic status.

Despite the high prevalence, assessment and treatment rates for sleep disorders remain low.¹ Many undiagnosed patients with sleep disorders may have underlying disruption to their circadian rhythm.

WHAT IS CIRCADIAN RHYTHM, AND WHY IS IT ESSENTIAL TO MAINTAIN IT?

Circadian rhythm is a 24-hour cycle that organises biological processes in alignment with external cues such as light, temperature, and mealtimes. Governed by the suprachiasmatic nucleus (SCN), which is in the anterior part of the hypothalamus, it is influenced by genetics and environment and dictates sleep and wake cycles.^2,3

Disruption of this cycle has long-term consequences, including increased risks of obesity, diabetes and cardiovascular disease, and a weakened immune system.³ Circadian misalignment impairs physiological processes and has detrimental effects on insulin sensitivity, energy expenditure, immune function, blood pressure, and cardiac modulation by the autonomic nervous system.⁴

Mentally, circadian misalignment can cause immediate effects -think irritability, anxiety, or a dip in cognitive sharpness after just one restless night. In the longer term, sleep disturbances, including insomnia, sleep apnoea, and circadian rhythm disorders, are common among individuals with psychiatric disorders.⁵

Chronic sleep issues also play a role in the mechanisms of neurodegenerative diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD), as well as others.⁶ Consequently, a regulated circadian rhythm forms the bedrock of physical vitality and mental well-being.