Nearly one in five people sent to top clinics with a multiple sclerosis label turned out not to have the disease—and the fallout is real.
Story Snapshot
- A specialty-clinic study found almost 20% of referred multiple sclerosis cases were misdiagnosed.
- Misdiagnosis can expose patients to risky drugs and delay real treatment.
- Christina Applegate says her doctors told her she does not have multiple sclerosis after all.
- Other experts peg misdiagnosis closer to 10% overall, and 15% in pooled research.
What the data actually says about “one in five”
A 2019 peer-reviewed review summarized by the federal Agency for Healthcare Research and Quality reported that nearly 20% of patients referred to two academic multiple sclerosis centers were misdiagnosed and did not have multiple sclerosis. Those are not walk-in patients from the general public. They are complex or questionable cases sent to expert clinics. The number warns us about a real problem, but it does not mean 20% of all people with a multiple sclerosis diagnosis are misdiagnosed nationwide.
The same summary details harsh consequences: people took high-risk, disease-modifying drugs they did not need and missed timely care for their actual illness. That is not a paperwork error. That is avoidable harm. An accurate diagnosis is not a luxury item; it is step one for safety. Americans expect second opinions on big financial choices. They deserve the same for a life-changing medical label that can reshape work, family, and finances.
Why multiple sclerosis is tricky to pin down
Multiple sclerosis has no single “yes or no” test. Doctors use clinical signs, magnetic resonance imaging scans, spinal fluid, and time to apply criteria. Symptoms can mimic other conditions, and white spots on MRI can come from aging, migraines, or small-vessel disease. Overreliance on scans or misreading criteria invites error. That mix explains why some people get labeled too soon, while others wait too long for the right call.
Celebrity stories show the human side of that gray zone. Christina Applegate said a doctor told her, “Congratulations, you don’t have multiple sclerosis,” years after she believed she did. Reports say doctors did not offer a replacement diagnosis. That does not settle the science, but it underscores how messy real cases can be and how vital it is to revisit a diagnosis when the pieces do not fit.
The push and pull in the numbers
Some neurologists say the best studies put misdiagnosis closer to 10% overall, not 20%. A 2024 research review pooled six studies and estimated a 15% misdiagnosis rate across varied settings, with wide ranges across studies. Both points are fair. The “one in five” figure comes from a referral population primed for hard cases. The broader literature lands lower on average. Sensible reading: misdiagnosis is common enough to demand action, even if the exact rate depends on where you look.
Conservative common sense applies here. Precision matters. Headlines should not turn a specialty-clinic warning into a national verdict. But soft-pedaling the problem serves no one. When estimates range from single digits to one in five, families deserve clearer standards, faster second looks, and transparency about uncertainty.
How patients and clinicians can cut the error risk now
Patients can ask four focused questions: What specific signs meet the criteria today? What else could this be? What do the magnetic resonance imaging scans show over time, not just once? What is the plan to recheck the diagnosis if new facts arise? Clinicians can slow down before starting heavy drugs, confirm that magnetic resonance imaging lesions match typical multiple sclerosis patterns, and document objective relapses. When doubt lingers, seek an independent review at an expert center.
“You don’t get misdiagnosed and then all of a sudden, I’m better”: Christina Applegate announced Tuesday that she was misdiagnosed with multiple sclerosis, or MS, more than five years after announcing she had been told she had the chronic condition.
It turns out, a misdiagnosis… pic.twitter.com/ew5O3qiPvW
— CBS Mornings (@CBSMornings) October 21, 2026
Health systems can help by setting second-opinion triggers before expensive or risky treatments, standardizing magnetic resonance imaging protocols, and tracking reversals. The 2019 analysis linked misdiagnosis to real harm. The 2024 pooled estimate shows the problem spans settings. The fix is not a miracle test. It is disciplined criteria, better imaging standards, and the humility to revisit a call. That is how you protect patients without scaring them, and how you spend health dollars like they are your own.
Sources:
cbsnews.com, psnet.ahrq.gov, cbc.ca, people.com
