Sleep and circadian rhythms are two closely linked but distinct biological processes that touch nearly every aspect of how our bodies and brains function. Circadian rhythms are the natural, internal biological cycles that our bodies repeat approximately every 24 hours. These rhythms are driven by the brain and are influenced by a variety of internal and external cues, such as light and darkness, food intake, and physical activity. Of all the processes governed by our circadian rhythms, sleep is perhaps the most familiar and one of the most important for brain health. Given how fundamental these processes are to our overall well-being, researchers have increasingly turned their attention to how disruptions in sleep and circadian rhythms might contribute to neurodegenerative diseases like Alzheimer’s disease (AD).

Considerable evidence from animal models and patients has implicated both sleep and circadian function in key processes involved in brain health, brain aging, and AD, including amyloid plaque and tau tangle formation. These disruptions also affect glia, the different support cells of the brain that include astrocytes, microglia, and oligodendrocytes, which help maintain healthy brain function. Moreover, population health studies suggest that poor sleep or misaligned circadian rhythms may promote dementia risk in humans. Despite the growing evidence linking sleep, circadian rhythms, and AD, our understanding of the underlying mechanisms remains quite superficial, and many important unanswered questions remain.

This consortium’s goal is to answer those questions and advance the field’s understanding of how sleep and circadian rhythms are linked to AD, and to determine whether disruptions in these functions worsen AD pathology or if AD pathology worsens these disruptions. Perhaps it is both, resulting in a vicious cycle between the two. Beyond understanding these mechanisms, the consortium also intends to translate this knowledge into actionable treatments. Recent studies have shown promising potential for various sleep interventions in reducing AD risk, so the consortium plans to develop sleep-targeted therapies to treat and/or prevent AD progression. The consortium will seek to build upon some of these studies and test other approaches to assess their impact and viability.