Background : Dementia is a leading cause of disability and mortality in Europe, yet no recent harmonised assessment has described its impact across the European Union (EU-27) and the WHO European Region.

Methods : We used data from the Global Burden of Disease Study 2023 (GBD 2023) to estimate prevalence, mortality, and disability-adjusted life years (DALYs) for dementia from 1990 to 2023. Estimates were produced for the EU-27 and the WHO European Region, by age and sex. Non-fatal outcomes were modelled using DisMod-MR 2.1, and dementia-attributable mortality was estimated using an excess-mortality framework. We also quantified DALYs attributable to six modifiable risk factors.

Findings : In 2023, 7.76 million people (95% UI 6.69–8.72) were living with dementia in the EU-27 and 12.28 million (10.44–13.90) in the WHO European Region, representing ∼90% increases since 1990 despite modest declines in age-standardised prevalence. Prevalence was nearly twice as high in women as in men. Dementia rose from the eighth to the third leading cause of death in the EU-27. Dementia accounted for 5.49 million DALYs (2.44–11.41) in the EU-27. An estimated 41% (24.4–57.4) of dementia DALYs in the EU-27 were attributable to modifiable risk factors, particularly ambient particulate matter pollution, high fasting plasma glucose, and high body-mass index, which are disproportionately concentrated in socioeconomically disadvantaged populations.

Interpretation : Despite modest declines in age-standardised rates, the absolute burden of dementia in Europe continues to rise, driven by population ageing. The substantial contribution of modifiable risk factors highlights major opportunities for prevention. Robust, country-specific estimates are essential to guide integrated strategies combining prevention and care planning.