Epidemiology of Multiple Sclerosis

Multiple sclerosis (MS) is a chronic immune-mediated disorder characterised by demyelination and neurodegeneration within the central nervous system. Its global distribution exhibits marked geographical gradients, with highest incidence and prevalence in temperate regions of North America, Europe and Australasia and lower burdens near the equator. Over recent decades, reported rates have risen, reflecting both genuine increases and improved detection through refined diagnostic criteria and expanded case-finding methods. Peak onset typically occurs in early adulthood, although emerging data indicate a trend towards older age at diagnosis in some populations. A persistent female predominance, often exceeding a two-to-one ratio, has been documented worldwide. The epidemiological profile of MS is shaped by interacting genetic susceptibilities, environmental exposures—such as vitamin D insufficiency and viral infections—and demographic factors. Standardised measures, including age-standardised incidence, prevalence and disability-adjusted life years, guide resource allocation and highlight the long-term impact of this potentially disabling disease. Continued harmonisation of study designs and enhanced registry infrastructure are essential to accurately monitor evolving trends and inform targeted prevention and care strategies.

Research from Nature Portfolio

A study assessing a national French administrative health database against a regional MS registry found only moderate concordance in case identification and an average five-year delay in registry entry when relying on administrative records alone. The findings emphasise the value of specialised registries for timely and comprehensive epidemiological surveillance and the need to refine case definitions in routine data sources to reduce bias in MS research.

Epidemiology of Multiple Sclerosis publication trend

The graph below shows the total number of articles in epidemiology of multiple sclerosis across all publications each year (not limited to Nature Index journals).

Technical terms

Incidence: The number of new cases of a disease occurring in a defined population during a specific time period.

Prevalence: The total number of existing cases of a disease in a population at a given point in time.

Relapsing–remitting multiple sclerosis (RRMS): A form of MS characterised by clearly defined attacks of worsening neurological function followed by partial or complete recovery.

Disability-adjusted life year (DALY): A measure combining years of life lost due to premature mortality and years lived with disability, reflecting overall disease burden.

Administrative database: Routinely collected health data, such as insurance claims or hospital discharge records, used for epidemiological research.

References

1. Increasing age of multiple sclerosis onset from 1920 to 2022: a population-based study. Journal of Neurology (2023).
2. Performance of administrative databases for identifying individuals with multiple sclerosis. Scientific Reports (2023).
3. Age-standardized incidence, prevalence, and mortality rates of autoimmune diseases in adolescents and young adults (15–39 years): an analysis based on the global burden of disease study 2021. BMC Public Health (2024).
4. Global, regional, and national burden of multiple sclerosis 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016. The Lancet Neurology (2019).
5. Geographical Variations in Sex Ratio Trends over Time in Multiple Sclerosis. PLOS ONE (2012).
6. Environmental Risk Factors for Multiple Sclerosis: A Review with a Focus on Molecular Mechanisms. International Journal of Molecular Sciences (2012).
7. Spatial Analysis of Global Prevalence of Multiple Sclerosis Suggests Need for an Updated Prevalence Scale. Multiple Sclerosis International (2014).