A respected study says nearly one in five specialty-clinic MS diagnoses were wrong—and Christina Applegate’s reversal just put a human face on that risk.
Story Snapshot
- Specialty-center reviews found many patients labeled with multiple sclerosis did not have it.
- Christina Applegate says doctors later told her she does not have multiple sclerosis.
- Experts warn wrong diagnoses can trigger risky drugs and delay real care.
- Other neurologists peg the broader rate closer to 10% and below 5% in Canada.
What the data really shows about “one in five”
Cedars-Sinai researchers reviewed patients sent to two academic multiple sclerosis clinics. Nearly 20% had been misdiagnosed with multiple sclerosis, according to the Agency for Healthcare Research and Quality summary of the study. These were referral cases, often the toughest calls. That matters because specialty clinics see complex patients. Still, the takeaway is clear: diagnostic error in this lane is not rare, and it carries real consequences for people and for costs.
Other evidence pushes the estimate down when you look beyond specialty referrals. A 2024 systematic review pooled six studies and landed at about 15% misdiagnosis across mixed settings. A University of Texas Southwestern specialist told the Associated Press that the best studies suggest about 10%. A Canadian leader in the field estimated below 5% in Canada, which likely reflects system differences and stricter gatekeeping. The exact rate depends on who is counted and where they are seen.
Why multiple sclerosis is so easy to get wrong
Multiple sclerosis has no single “yes/no” test. Doctors rely on patterns over time, magnetic resonance imaging findings, spinal fluid clues, and how symptoms spread in the nervous system. Small errors add up. Overreading magnetic resonance imaging spots that come from aging, migraines, or past infections can mimic multiple sclerosis. Misusing diagnostic criteria can seal the wrong label. The result is a perfect storm where speed and pressure to “name it” can set people on the wrong path.
Real harms follow a false label. People may start potent immune drugs they do not need. Those medicines can cause infections, organ damage, and costs that hit families hard. Worse, the real illness waits in the wings without proper care. The Agency for Healthcare Research and Quality flagged both risks: adverse drug events and delays in correct treatment after a wrong multiple sclerosis diagnosis. That is why accuracy matters more than a fast answer in gray-zone cases.
Christina Applegate’s reversal, and what it teaches
Christina Applegate says a doctor told her, “Congratulations, you don’t have multiple sclerosis.” Reports note that her team did not give a new diagnosis to explain her symptoms. That lack of a neat ending is common in neurology. Symptoms can overlap across immune, metabolic, and functional disorders. Her story does not set the rate, but it shows the stakes. Labels shape care, identity, and hope. Changing one can feel like losing the map while still on the road.
“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
Clinicians warn against reading her case as the national norm. One expert framed her experience as a lesson in guarding against bias and in keeping second opinions on the table, not proof that most diagnoses are wrong. That fits conservative common sense: protect patients from avoidable harm, verify before you commit to lifelong treatment, and seek clarity without panic. The system should make second looks easy, fast, and affordable—because the bill for mistakes lands on families.
How patients and doctors can push error rates down
Patients can ask three plain questions: What specific signs point to multiple sclerosis in my case? What findings argue against it? What is Plan B if new data disagree? Doctors can slow down when the story and the scans do not match. Use standard magnetic resonance imaging protocols. Double-check cerebrospinal fluid analysis when the picture is muddy. When doubt lingers, refer to a multiple sclerosis specialist. These steps do not slow care; they prevent wrong turns that cost years.
Health systems can help by normalizing second-opinion pathways, funding independent magnetic resonance imaging reads, and tracking outcomes after diagnosis changes. Payers could cover a rapid review bundle for high-risk labels like multiple sclerosis. The aim is not to inflate fear; it is to trim waste, reduce harm, and get people to the right door sooner. That is good medicine and good stewardship. Precision beats speed when the drugs are strong and the label lasts a lifetime.
Sources:
bbc.com, cbsnews.com, psnet.ahrq.gov, cbc.ca, people.com, apnews.com
