Alzheimer’s disease and daily body clock problems: which comes first?

Circadian dysfunction is a prominent feature of Alzheimer's disease (AD) that may exacerbate its pathology.

• Circadian disruption is traditionally seen as a symptom of AD but may actually worsen the disease.
• Both human and animal studies indicate a link between sleep, circadian rhythms, and amyloid deposition.
• Increased amyloid-beta (Aβ) levels have been observed in sleep-deprived mice.
• Conditions such as sleep apnea and insomnia in humans may be associated with AD.
• Melatonin, which regulates circadian rhythms, is dysregulated in AD and could protect against toxic Aβ.
• Further studies are needed to understand how the circadian system impacts the development of AD.

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