Preliminary results from a new study identified nearly 1 million people living with MS in the United States. This is more than twice the previously reported number, which was a result of a 1975 national study.
 
For some time, many experts have doubted the accuracy of the estimate of 400,000 affected by MS in the United States, since this estimate was based on scientific research done to establish the prevalence of MS before MRI was introduced as a diagnostic method and before any disease-modifying treatments were approved for use. With these advancements, it is likely that more people are being accurately diagnosed, and that people with MS are living longer. For this reason, it has for some time been considered likely that the number of individuals affected by MS may be significantly higher. 

Diseases that affect fewer people than others may be considered a lower priority for funding by government agencies and private foundations that support research and support services. These new results indicate that research and assistance programs may be severely underfunded.

The study was presented at the seventh joint ECTRIMS-ACTRIMS meeting in Paris.