Can Better Sleep Slow Alzheimer's?

New BrightFocus-funded research shows that disrupted sleep could play a role in Alzheimer’s disease, and that restoring healthy sleep patterns could help slow the disease’s progression.

Doctors have long known that people with Alzheimer’s have trouble falling and staying asleep, sometimes years before official diagnosis. These disruptions have typically been viewed as a symptom of a brain already in decline.

But what if poor sleep isn’t just a consequence of Alzheimer’s, and is instead helping drive the disease forward?

That’s the question guiding the work of BrightFocus Alzheimer’s Disease Research grantee Ksenia Kastanenka, PhD, Massachusetts General Hospital. In a new study published in the journal Alzheimer’s and Dementia, her team found that restoring healthy sleep in a mouse model of Alzheimer’s using a common sleeping pill reduced hallmark signs of the disease and improved brain function. The findings suggest that targeting sleep could open a new path for treating Alzheimer’s, and that an existing, FDA-approved drug might help get us there faster.

Why Sleep Matters in Alzheimer’s

Sleep is essential for brain health, helping consolidate memories and clear waste products from the brain. In Alzheimer’s disease, this system breaks down. People with Alzheimer’s often experience fragmented sleep and disruptions in deep, restorative sleep, and these changes are closely linked to faster disease progression.

Dr. Kastanenka has spent her career investigating whether this connection is more than correlation. Early in her research, she used innovative imaging tools to observe brain activity in mouse models of Alzheimer’s and noticed something striking: disruptions in “slow waves,” the rhythmic brain activity that defines deep sleep.

“Slow waves are like ocean waves that wash over the outer layers of our brains when we sleep,” she said. These waves are critical for memory consolidation, and when they break down, the consequences may be profound.

With support from BrightFocus, Dr. Kastanenka went on to show that restoring these sleep-related brain waves could actually slow Alzheimer’s progression in animals, helping establish a now-growing area of research linking brain circuits, sleep, and neurodegeneration.

Teaching an Old Pill New Tricks

Armed with a better understanding of how sleep disturbances might drive Alzheimer’s disease progression, Dr. Kastanenka wanted to know if it was possible to halt this process. She worked with a computational biologist to screen for drugs that would help restore sleep and found the answer hiding in plain sight.

The team identified zolpidem, commonly known as Ambien, as a promising candidate. The drug, which is already widely prescribed for insomnia, works by enhancing signaling in the brain that promotes sleep.

Dr. Kastanenka and her colleagues tested zolpidem in a mouse model of Alzheimer’s disease. They found that the drug restored normal sleep patterns, including the slow-wave activity critical for memory and brain health.

But the most striking changes were seen in the brain itself. Mice treated with zolpidem had brains with fewer amyloid plaques, the toxic protein clumps that are a hallmark of Alzheimer’s disease, along with improved brain cell health and stronger performance on memory tasks.

Together, the findings suggest that restoring sleep does more than improve rest; it may directly slow the biological processes that drive Alzheimer’s progression.

“A simple sleeping pill could potentially stave off Alzheimer’s disease,” Dr. Kastanenka said.

A Faster Path to New Treatments

Alzheimer’s disease affects millions of people worldwide, and treatment options remain limited. Dr. Kastanenka’s work points to a new and potentially more accessible strategy: targeting sleep as a way to intervene before significant damage occurs.

Because zolpidem is already FDA-approved, this approach could also accelerate the path to clinical use. Drug repurposing can significantly reduce the time and cost required to bring new treatments to patients compared to developing therapies from scratch. Just as importantly, the research re-frames sleep as a critical part of Alzheimer’s biology: not just a symptom, but a potential driver of disease.

“If there is one thing we have learned,” Dr. Kastanenka said, “it’s that a good night’s sleep is more than just a luxury. It’s a frontline defense.”

Dr. Kastanenka added that her research was made possible by continued support from BrightFocus Foundation. She received her first Alzheimer’s Disease Research award as a postdoctoral fellow, supporting the studies that launched her career as an independent researcher with her own lab. Since then, she has continued to receive funding from Alzheimer’s Disease Research, including the award supporting this project.

“By identifying promising scientists at vulnerable early career stages, BrightFocus continues to transform the landscape of Alzheimer’s research, turning ‘niche’ fields into blossoming areas of discovery, ultimately bringing us closer to a cure,” she said.

She hopes her findings reshape how we think about Alzheimer’s prevention, highlighting sleep as a powerful and often overlooked factor.

“For the sake of your brain health, go get a solid eight hours of shut-eye,” Dr. Kastanenka said. “But right before you hit the snooze button, consider making a donation. It’s the only way to ensure that while you are dreaming, we are in the lab working to make Alzheimer’s a thing of the past. Rest easy: we have got the night shift covered!”