6 Reasons Researchers No Longer Deem Dementia ‘Untreatable’

Not only do we not have a cure for dementia yet, but we don’t even have a single test that can diagnose it outright.

So, why does 2026’s huge World Alzheimer Report, co-authored by Alzheimer’s Disease International (ADI) and health writer Paul Gallagher, suggest that “Alzheimer’s disease is no longer universally described as untreatable” by researchers?

This “mood” among scientists, the paper added, is “infectious”.

Indeed, Professor Colin Masters, a neuroscientist whose research contributed to the amyloid hypothesis of dementia, told ADI: “Alzheimer’s disease is going gangbusters at the moment.

“The feeling of optimism has never been so strong. We’ve moved from a great nihilistic, pessimistic era five years ago towards an era of extreme optimism”.

There’s not one single breakthrough that’s left the scientific community so encouraged. We still don’t have a cure for dementia, for instance.

But finding one “feels like a more palpable prospect than ever before”, the report reads, because of multiple changes in research, medication, and approaches.

In just the past five years, multiple drugs, like lecanemab and donanemab, have been shown to slow dementia.

That is not a complete “cure”, but they “marked an important scientific milestone, providing the first evidence that therapies targeting amyloid pathology can slow clinical decline by about 30%”.

Amyloid plaques are sticky clusters of proteins in the brain that have long been linked to dementia development.

Not all experts agree these drugs are as effective as hoped. But the arrival of these medications to multiple countries “was a huge moment because it showed you could change the course of the disease”, said Professor Cath Mummery, director of the UK’s Dementia Trials Network.

“They show consistent, significant change. So, for me, the breakthrough is that the amyloid hypothesis, which we’ve been chasing for decades, was confirmed at least in part… That’s the foundation. It’s the first brick, and there’s an awful lot to build on.”

The paper notes that as of the time of writing, 158 potential dementia therapies were being trialled in 192 trials worldwide.

This is part of “an era of unprecedented activity,” the report stated. The number of possible medications under review right now is up 40% from the last decade.

In 2026 alone, we can expect results from eight Phase III trials that test drugs and other therapies on people.

As of yet, we haven’t found a one-and-done test that can unambiguously tell doctors whether someone has dementia.

And as the report argues, even the best treatments mean little if the majority of people living with dementia are never identified in the first place.

But at this year’s Alzheimer’s Association International Conference, announcements “centred on making Alzheimer’s diagnosis earlier and more accessible”, including through potential blood tests.

Additionally, “blood-based assays, advanced neuroimaging, and genetic profiling are also making it possible to identify Alzheimer’s pathology years before cognitive symptoms fully manifest,” the report continued.

Meanwhile, studies like the TRAILBLAZER-ALZ 3 research are working out whether very early intervention makes dementia treatment more effective.

The report also said research is expanding from primarily observational studies to participation in large interventional and prevention-focused clinical trials.

This comes after a standing commission from The Lancet which found that up to 45% of dementia risk could be down to “potentially modifiable” lifestyle factors.

One initiative, for instance, aims to give at-risk older people lifestyle interventions, like controlling their blood pressure and optimising their diets, to see whether this helps to slash dementia incidence.

More than a third of drugs currently “in the pipeline” for possible dementia-related applications are existing, repurposed medications.

One example is atomoxetine, an ADHD drug, which showed mixed results in a trial that sought to find out whether it could slow cognitive impairment.

If drugs like these are found effective, their current status as an approved medication could make clearing them for other conditions go a little faster.

“As with diseases such as cancer, it is increasingly thought that the most effective approach to Alzheimer’s may involve multiple therapies working together against different aspects of the disease,” the report said.

So it’s a good thing the research community is looking at combined treatments, like pairing a tau vaccine with an anti-amyloid medication.

Overall, the paper said: “Dementia is being recast not as a gradual decline towards an inevitable loss of cognition, but as a continuum that might be interrupted or slowed, enabling many more years with a good quality of life.”