New Alzheimer’s Drugs Don’t Work? What the Cochrane Review Actually Says

If you saw the recent headlines about Alzheimer’s drugs and felt your stomach drop, that reaction makes complete sense.

You are not overreacting.

And you are not wrong to feel confused.

Because for the past couple of years, many of you have heard about these new drugs, Lecanemab and Donanemab, described as breakthroughs. The first treatments ever that actually slow the progression of Alzheimer’s disease, not just manage symptoms. And now a major, highly respected research organization is saying they don’t work?

I hear from caregivers all the time who say things like, “I don’t know what to believe anymore. One week it’s a breakthrough, the next it’s useless. My mother was just approved to start one of these drugs, and now I’m terrified we made the wrong decision.” Or, “How are we supposed to make decisions for our loved ones when the experts can’t even agree on what works?”

Those concerns, those questions, all of them are completely warranted. This is genuinely complicated, and you deserve a clear, honest breakdown of what this study actually found, what experts are saying, its limitations, and most importantly, what it means for you and your family, practically speaking.

By the end of this post, you’re going to understand what this Cochrane review actually looked at, why it’s creating so much debate, and the three questions you should be able to bring to your loved one’s doctor, regardless of which side of this you fall on.

Why These Drugs Mattered So Much in the First Place

For decades, Alzheimer’s disease had no treatment that could slow its progression. Medications like donepezil can help manage some symptoms, but they don’t touch the underlying disease process. They don’t change how quickly Alzheimer’s advances.

Lecanemab and Donanemab are part of a class of drugs called anti-amyloid monoclonal antibodies. They’re designed to target and clear amyloid plaques from the brain. These plaques are a hallmark feature of Alzheimer’s disease, and the theory is that if we can clear the plaque, we might be able to slow how quickly the disease progresses.

These newer drugs are designed for mild cognitive impairment or early dementia. Not for moderate or advanced dementia. Early stage only. That’s an important detail, and I’m going to come back to it.

When these drugs received FDA approval, it felt like something. Not because they cured anything, but because for the first time, there was real evidence that the disease process itself might be slowed.

What the Cochrane Review Actually Found

So let’s look at what actually happened.

In April 2026, an organization called the Cochrane Collaboration published what they call a systematic review. For those of you who aren’t familiar, Cochrane is one of the most well-respected, independent research review bodies in the world. They don’t do new research themselves. What they do is take a large number of existing studies and combine them to look for patterns. The idea is that combining data from many studies gives you a more reliable answer than any single study alone.

For this review, the researchers looked at 17 clinical trials involving over 20,000 participants.

Their conclusion? The effect of these drugs on cognitive function and dementia severity at 18 months was, in their words, trivial. And on a functional level, meaning a person’s ability to do daily tasks, they called the effect small at best.

They also found that these drugs significantly increase the risk of something called amyloid-related imaging abnormalities, or ARIA, which essentially means the brain swells. There’s swelling and bleeding, and it shows up on MRI scans. In the clinical trials, somewhere between 12 and 35 percent of patients experienced ARIA. Most of those cases were mild and went away on their own. But in about one to two percent of patients, the symptoms were serious, including headaches, confusion, seizures, and vision changes.

So on its face, the review is saying questionable benefit, real risk. And that’s an alarming combination to hear.

Why Are Researchers Pushing Back on This Study?

But here’s where things get complicated, and what most of the headlines are missing.

I want to be clear that this is not a simple story. Anyone who’s presenting this study as “these drugs are useless and don’t help,” or “this study is completely wrong,” they’re not giving you the full picture.

Here’s the core problem that many researchers are pointing to. Of the 17 studies the Cochrane review analyzed, 12 of them were drugs that failed. Some failed badly. Three of the studies were on a drug called Aducanumab, which failed one of its two pivotal clinical trials and was eventually withdrawn from the market entirely. Many of the other drugs in the analysis were discontinued because they didn’t work.

So only two of the 17 drugs in this review are actually FDA-approved and available to patients today. Those are Lecanemab and Donanemab.

The review essentially averaged the results of 12 drugs that didn’t work together with two drugs that did work, and then concluded that the whole class of drugs doesn’t work.

One researcher put it this way: mixing up drugs that failed with the ones that actually changed clinical practice turns therapeutic practice into statistical noise. It’s a little bit like averaging the test scores of 12 students who failed the exam with two students who passed, and then concluding that nobody passed the exam.

Now, to be fair, the Cochrane researchers would say that this is exactly what systematic reviews do. They evaluate a whole class of treatments. They don’t just cherry-pick successes. And their point about the risk of brain swelling and bleeding is real, regardless of which drug we’re talking about. They all came with the risk of ARIA.

What Did the FDA and UK Regulators Actually Decide?

But here’s where it lands practically.

The UK regulator, the MHRA, reviewed Lecanemab and Donanemab separately and concluded there is a small but meaningful benefit. The FDA in the United States approved both drugs. These are the same regulatory bodies that are required to weigh real-world risk against real-world benefit.

They did not conclude that these drugs are useless. In fact, when the MHRA licensed Lecanemab and Donanemab, they specifically excluded people who carry two copies of the APOE4 gene, and people on blood-thinning medication, from eligibility, because of their elevated risk. That kind of careful, individualized line-drawing is the opposite of “this doesn’t work.” That’s regulators saying the benefit is real, but who it’s right for matters enormously.

This is a genuine scientific debate. It’s not a conspiracy. It’s not one side lying. Smart, well-meaning people are looking at the same data and reaching different conclusions about how to interpret it. That is how science works sometimes, especially at the frontier of a complex disease.

If Your Loved One Is Already on One of These Drugs

I want to say this very clearly: this review does not mean that if your loved one is already on Lecanemab or Donanemab, you should stop the medication. It is not a recall. There’s no safety emergency. This is a research debate.

If you have concerns about whether this is the right path for your loved one, that’s a conversation to have with your loved one’s neurologist, not a panic decision to discontinue.

Three Questions to Bring to Your Loved One’s Doctor

If your loved one is being considered for one of these drugs, this review is actually a useful tool. It’s a reminder to have a very open, honest, informed conversation with the prescribing physician. So here are the three questions I’d encourage you to bring to that conversation.

What specific benefit do you realistically expect for my loved one, and how will we know if it’s working?

The clinical trials show that these drugs slow decline by roughly 25 to 35 percent. They don’t stop it. They don’t reverse it. They slow it, by months, not by years. For some families, that’s meaningful and significant. For others, given the appointments required, the monitoring required, and the risk of side effects, it might not be worth it. Only you can decide that, but you should decide it with accurate expectations and an open conversation with the doctor prescribing it.

What is my loved one’s specific risk for ARIA?

Risk is not the same for every person. People who carry two copies of the APOE4 gene have a significantly higher risk of brain swelling and bleeding on these drugs. Some clinics say they won’t even offer these treatments to people who have two copies of the APOE4 gene. Others will take that risk and proceed anyway. People on blood thinners face elevated risk as well. Your neurologist should be walking you through your loved one’s individual risk profile, not just average statistics.

Is my loved one still safe for this treatment? Is this even something we should be considering?

These drugs are only studied and approved for early Alzheimer’s or mild cognitive impairment. So if your loved one has progressed beyond that stage, these drugs aren’t indicated for them, regardless of what the research says. The window for these treatments is narrow, and that matters. It might also be another reason why pursuing a diagnosis early is so important, if you’re someone who would want to try one of these treatments down the road.

I want to offer a mindset shift here. Understanding that there’s a genuine scientific debate doesn’t mean you’re stuck in uncertainty. It means you’re informed. And being informed means you can ask better questions, set more realistic expectations, and make decisions that are right for your specific family, not for a headline.

I’m Sorry This Isn’t a Clearer Answer

All right, Careblazer. I’m sorry dementia treatments are this confusing and unclear, and I’m even more sorry that what we’re seeing isn’t all that significant or wonderful. What we’re looking at is pretty modest in terms of benefit, but that can still mean a lot for some families.

I hope this doesn’t bring on any hopelessness. I hope it doesn’t bring on any fear either. I hope it gives you an honest look at both sides of something that just made headlines, so you’re standing on solid ground instead of a headline.

Navigating dementia, especially right now, feels like it’s constantly changing. It feels like there isn’t a lot of clear, settled ground to stand on. And it’s especially hard because even the experts in this field do not fully agree with each other.

I hope this helps you in some way. If you want to dig into the details yourself, rather than take my word for it, here is the full Cochrane systematic review (April 2026).

And if you’re carrying other hard, confusing parts of this journey too, like dementia hallucinations, I want you to know none of it means you’re doing this wrong. It just means you’re doing something genuinely difficult.

You Don’t Have to Carry This Alone

I know how isolating this journey can feel, especially in moments like this one, when even the experts can’t agree and you’re the one left to make the call for someone you love.

That is exactly why I created the Care Collective. Inside, we talk through situations just like this one together. Not just what’s happening in the research, but how to actually have these conversations with doctors, how to make these decisions as a family, and how to take care of yourself while you’re doing it. You’ll get to know me, I’ll get to know you, and you’ll get to know other Careblazers who are walking this same road. You can learn more here.

Sources and References

• Cochrane Systematic Review: Anti-amyloid monoclonal antibodies for the treatment of Alzheimer’s disease (April 2026)
• FDA Traditional Approval of Leqembi (Lecanemab)
• CLARITY AD Trial — Lecanemab in Early Alzheimer’s Disease, New England Journal of Medicine
• Alzheimer’s Association: ARIA Overview and Management
• National Institute on Aging: Alzheimer’s Disease Genetics Fact Sheet
• UK MHRA approval coverage — Alzheimer’s Disease International