PARLIAMENTARY WRITTEN QUESTION
(29 August 2025)

Young onset dementia is defined as dementia diagnosed under the age of 65.

The dementia diagnosis rate is not calculated for patients aged under 65 years old. This is because the numbers of patients known to have dementia in the sample population age groups comprising those aged between zero and 64 years old are not large enough for reliable estimates to be made.

The dementia diagnosis rate for patients aged 65 years old and over is calculated and published monthly via the Primary Care Dementia Data publication, which is available at the following link: https://digital.nhs.uk/data-and-information/publications/statistical/primary-care-dementia-data

This publication does include a monthly count of the number of patients aged 65 years old and under who do have a dementia diagnosis on their patient record. This is expressed as a raw count and as a percentage of registered patients aged between zero and 64 years old.