The Alzheimer's Pathways Sleep Study (ALPS) is a randomized controlled trial testing whether a time-in-bed restriction intervention can increase slow-wave activity to improve cognition and Alzheimer's pathophysiology in older adults with poor sleep.
Slow-wave activity (0.5-4 Hz EEG activity) during non-rapid eye movement sleep is consistently associated with better cognitive performance in older adults.
Paradoxically, longer total sleep times in older adults are often associated with poorer cognition and general health.
The ALPS trial uses a time-in-bed (TiB) restriction intervention designed to increase slow-wave activity through homeostatic sleep drive.
The ALPS trial targets four primary outcomes linked to a conceptual model connecting slow-wave activity with Alzheimer's pathophysiology and memory.
The ALPS trial is designed to enroll 116 participants aged 65-85 with poor sleep, randomized to TiB restriction or attention-matched control.
Safety measures are described as necessary components of the TiB restriction protocol to minimize risks associated with sleep restriction.
The authors characterize behavioral enhancement of homeostatic sleep drive through TiB restriction as a promising approach to improve memory performance and Alzheimer's pathophysiology.
This paper describes the design and methods of a clinical trial called the Alzheimer's Pathways Sleep Study (ALPS). The study is based on evidence that a specific type of brain activity during deep sleep — called slow-wave activity — is linked to better memory and thinking skills in older adults, and may help protect against the buildup of Alzheimer's-related proteins in the brain. Interestingly, simply sleeping longer does not seem to provide these benefits; it is the quality of sleep, particularly the depth of slow-wave sleep, that matters. Standard behavioral sleep therapies improve sleep duration and efficiency but do not reliably boost slow-wave activity or cognition. To address this gap, ALPS is testing a novel approach: restricting the amount of time older adults spend in bed to about 85% of their usual time. The idea is that spending less time in bed builds up 'sleep pressure,' which in turn triggers more deep, slow-wave sleep when they do sleep. The trial is enrolling 116 adults aged 65–85 who have poor sleep, randomly assigning them to either follow this restricted sleep schedule or continue their normal sleep habits for four weeks. The study measures brain activity during sleep, hippocampal (memory-related) brain activation, blood levels of an Alzheimer's-related protein (amyloid beta 1-42), and memory test performance. This research suggests that strategically restricting time in bed — rather than simply encouraging more sleep — could be a behavioral (non-drug) strategy to enhance deep sleep quality and potentially slow cognitive decline and Alzheimer's-related changes in the brain. Because sleep restriction carries some risks, particularly excessive daytime sleepiness, the trial includes careful safety monitoring. The study has not yet reported results on whether the intervention works; this publication describes the trial's rationale, design, and procedures.
Dong Y, Habte R, Dessa K, Fletcher M, Ianni A, Lopresti B, et al.. (2026). The Alzheimer's Pathways Sleep Study (ALPS): an experimental randomized controlled trial to improve cognition and Alzheimer's pathophysiology through slow-wave sleep.. Trials. https://doi.org/10.1186/s13063-026-09505-w