Almost one in five people sent to top clinics with a multiple sclerosis label turned out not to have it, and the fallout is real.
Story Snapshot
- A 2019 study found nearly 20% of referred patients were misdiagnosed with multiple sclerosis
- Doctors warn that misdiagnosis brings risky drugs and delays real care
- Christina Applegate says doctors told her she does not have multiple sclerosis after years of believing she did
- Other estimates range from below 5% to about 15%, depending on setting
What the data actually shows about getting multiple sclerosis wrong
A peer-reviewed study of patients sent to two major multiple sclerosis centers found that nearly one in five did not have multiple sclerosis after expert review. These were not random walk-ins. They were people with a diagnosis or a strong question. That matters. But the number signals a real problem in tough cases, not a fringe mistake. The government’s patient safety arm summed up the risk in plain terms: wrong labels lead to harm and to lost time for the real illness.
Cedars-Sinai neurologist Dr. Marwa Kaisey put it bluntly in public comments: almost one in five people told they have multiple sclerosis “didn’t actually have it.” That line traveled far because it is simple and sharp. It also matches the referral-clinic finding and what many specialists see in second-opinion rooms. The core reason is structural, not scandalous. No single test diagnoses multiple sclerosis. Doctors must weigh symptoms, scans, and timing, and that mix can mislead.
Christina Applegate’s reversal is a human face, not a census
Christina Applegate told the world that a doctor said, “Congratulations, you don’t have multiple sclerosis.” Her case explains why this topic hit the front page. It shows how a famous person can live for years under a heavy diagnosis and then learn it was likely wrong. Reports say her doctors have not named a new cause for her symptoms. That lack of a firm answer does not erase the reversal; it shows how hard neurology can be.
Her story also teaches a civic point. Public policy should not rest on one case, no matter how well known. An anecdote opens our eyes; data should guide our steps. Specialists warn that headlines like “20% are wrong” can turn a clinic-based number into a national rate in the public mind. The evidence does not support that leap. The smarter takeaway is this: diagnostic error shows up often in complex or doubtful cases, and its true everyday rate remains less certain.
Why the numbers vary and where common sense lands
Different studies look at different groups. Referral centers see the hardest puzzles. Community clinics see the routine. A recent review pooled studies and estimated a misdiagnosis rate around 15%, while a respected neurologist pegs the rate closer to 10% overall, and a Canadian expert estimates it below 5% in Canada. None of these figures cancel the others; they reflect different settings and methods. The range argues for caution and for better, broader research.
Common sense says we should reward accuracy over speed. Pressure to diagnose earlier can save function for true multiple sclerosis. It can also cast too wide a net. Over-reading magnetic resonance imaging changes or stretching criteria can brand someone for life. That choice carries weight. Disease-modifying drugs can help the right patients. They can also cause side effects and cost a fortune when used on the wrong ones. Families deserve prudence anchored in facts, not in fear.
How patients and doctors can lower the odds of a wrong turn
Patients should ask three plain questions: What exact criteria do I meet? What else could cause this picture? What is the plan to confirm or correct over time? Clinicians should name the threshold for calling it multiple sclerosis and show how the scans and spinal fluid fit. When doubt lingers, label it clearly and set a follow-up schedule. A second opinion at a specialty center can catch mistakes early, especially when the story or the imaging does not quite add up.
“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
Policymakers should back two fixes that align with conservative values: transparency and accountability. First, publish real-world diagnostic accuracy dashboards for major conditions, anonymized and risk-adjusted. Second, tie public funding to clear diagnostic pathways that reduce false positives and false negatives. These steps protect patients, respect taxpayers, and reward clinics that do the careful work. More data and wiser guardrails beat louder headlines every time.
Sources:
cbsnews.com, psnet.ahrq.gov, people.com
