Carcaillon-Bentata L, Quintin C, Boussac-Zarebska M, et al. - According to estimates, there were about 24,000 and about 5,300 individuals with prevalent and incident young onset dementia (YOD), respectively, in France in 2016. Men exhibited a higher YOD frequency than women, which may be partially attributable to higher prevalence of cardiovascular and neurovascular diseases, substance abuse disorders, and traumatic brain injury in men.

• Data about the frequency of YOD in France is lacking.

• From the French national health data system, data were retrieved for 76% of the French population to estimate YOD prevalence and incidence in persons aged 40 to 64 years and assess the contribution of comorbidities to YOD incidence.

• Standardized prevalence rate and incidence rate were estimated to be 109.7/100,000 and 24.4/100,000 person-years, respectively, and were found to be higher in men compared with women.

• More than 55% of the gender difference in YOD incidence was explained by cardiovascular and neurovascular, neurological, psychiatric diseases, and traumatic brain injury.