What if you could stop Alzheimer's disease before it even begins? Northwestern University scientists have discovered that a decades-old, inexpensive drug already sitting on pharmacy shelves can prevent the toxic proteins that cause Alzheimer's from forming in the first place.

Published yesterday in Science Translational Medicine, the groundbreaking study reveals that levetiracetam — an FDA-approved anti-seizure medication that's been used safely for decades — can halt the production of amyloid-beta 42, the particularly nasty protein fragment that accumulates in Alzheimer's patients' brains.

🧠 A Different Approach to Fighting Alzheimer's

While current Alzheimer's drugs like lecanemab and donanemab work by clearing existing plaques from the brain (like cleaning up after a mess), this discovery is about prevention — stopping the mess from happening in the first place.

"We've identified this mechanism that prevents the production of the amyloid-beta 42 peptides and amyloid plaques," said Dr. Jeffrey Savas, the study's corresponding author and associate professor at Northwestern University Feinberg School of Medicine. "Our new results uncovered new biology while also opening doors for new drug targets."

🔬 How It Works: The Science Made Simple

The Northwestern team made several key discoveries:

1. Where the problem starts: Toxic amyloid-beta 42 proteins accumulate inside neurons' synaptic vesicles — the tiny packets that brain cells use to send signals to each other.
2. How the drug intervenes: Levetiracetam binds to a protein called SV2A, which slows down the recycling process of synaptic vesicles. This pause keeps amyloid precursor protein (APP) on the cell's surface longer, diverting it away from the pathway that creates toxic amyloid-beta 42.
3. The aging factor: In our 30s, 40s, and 50s, our brains naturally steer proteins away from harmful pathways. But as we age, that protective ability weakens. In brains developing Alzheimer's, too many neurons go astray.

"This is not a statement of disease; this is just a part of aging," Savas explained. "But in brains developing Alzheimer's, too many neurons go astray, and that's when you get amyloid-beta 42 production. And then it's tau, and then it's dead cells, then dementia, then neuroinflammation — and then it's too late."

⏰ The Critical Window: Very, Very Early

Here's the challenging part: To effectively prevent Alzheimer's symptoms, high-risk individuals would need to begin taking levetiracetam "very, very early," Savas said — possibly up to 20 years before symptoms appear.

"You couldn't take this when you already have dementia because the brain has already undergone a number of irreversible changes and a lot of cell death," Savas cautioned.

This means the ideal candidates would be people with genetic forms of Alzheimer's, including patients with Down syndrome. More than 95% of people with Down syndrome develop early and aggressive Alzheimer's by around age 40, because the APP gene is linked to the chromosome that's triplicated in their genome.

"If you started giving these patients levetiracetam in their teenage years, it could actually have a preventative therapeutic benefit," Savas suggested.

📊 Real-World Evidence: Mining Existing Data

Because levetiracetam is already widely used as an anti-seizure medication, the researchers could examine existing patient data to see if Alzheimer's patients who happened to take it fared differently.

They obtained clinical data from the National Alzheimer's Coordinating Center and found something promising: Alzheimer's patients who took levetiracetam experienced a significant delay from diagnosis to death compared to those taking other anti-epileptic drugs or no seizure medication.

"Although the magnitude of change was small (on the scale of a few years), this analysis supports the positive effect of levetiracetam to slow the progression of Alzheimer's pathology," Savas said.

🧬 Studying Down Syndrome Brains Revealed Early Changes

In addition to using genetically engineered mouse models and cultured human neurons, the scientists studied brain tissue from deceased Down syndrome patients who died in their 20s or 30s from accidents.

"By obtaining Down syndrome patient brains from people who died in their 20s or 30s, we know they would have eventually developed Alzheimer's, so it gives us an opportunity to study the very initial early changes in the human brain," Savas explained.

These brains showed the same accumulation of presynaptic proteins that the lab had found in mouse models — what researchers call the "paradoxical stage" of Alzheimer's disease, where presynaptic proteins accumulate before synapses are lost and dementia begins.

🔧 Next Steps: Making It Better

Savas acknowledged that levetiracetam "is not perfect" — the drug breaks down in the body very quickly. He and other researchers are now working on developing an improved version that would last longer in the body and better target the mechanism that prevents plaque production.

The discovery also opens doors for identifying entirely new drug targets based on this newly uncovered biology of how toxic proteins form in Alzheimer's disease.

💡 Why This Matters

This research represents a fundamental shift in how we might approach Alzheimer's disease:

• Prevention vs. treatment: Stopping toxic proteins from forming rather than trying to clear them after they've accumulated
• Early intervention: Potentially helping high-risk individuals decades before symptoms appear
• Existing drug: Levetiracetam is already FDA-approved, inexpensive, and has a well-established safety profile
• New understanding: Revealing exactly when, where, and how toxic proteins accumulate in the brain

For families with genetic forms of Alzheimer's or Down syndrome, this discovery offers something that's been in short supply: genuine hope for prevention.

"In our 30s, 40s and 50s, our brains are generally able to steer proteins away from harmful pathways," Savas reflected. "As we age, that protective ability gradually weakens. This is not a statement of disease; this is just a part of aging."

Now, thanks to this research, we might have a way to help our brains maintain that protective ability just a little bit longer — long enough to prevent one of the most devastating diseases of aging before it ever takes hold.

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The study was published in Science Translational Medicine on February 12, 2026. Funding was provided by the National Institutes of Health and the Cure Alzheimer's Fund.