Results of a large meta-analysis show that currently 3.9 million individuals are living with young-onset dementia. Among these patients, symptoms of the disease start before age 65.
Recent global young-onset dementia estimates have ranged from 42.3 to 54.0 per 100,000 population, the researchers noted. However, the new study, which included 74 global studies with 2.7 million participants, shows that the global age-standardized prevalence of young-onset dementia is 119.00 per 100,000 among individuals aged 30-64 years; there was little difference in prevalence between men and women. On the basis of the latest population estimates, these new prevalence data imply that there are approximately 175,000 persons with young-onset dementia in the United States.
Although the new global estimate of young-onset dementia is higher than previously thought, “it is still probably an underestimation owing to lack of high-quality data. This should raise awareness for policy makers and health care professionals to organize more and better care for this subgroup of individuals with dementia,” wrote the investigators, with first author Stevie Hendriks, MSc, Maastricht (the Netherlands) University, and the Young-Onset Dementia Epidemiology Study Group.
The study was published online July 19, 2021, in JAMA Neurology.
‘Essential’ data
Young-onset dementia is exceedingly rare in those aged 30-63 years (1.1 per 100,000) but is more prevalent at age 60-64 years (77.4 per 100,000). “Our findings fit the general observation that prevalence of dementia increases exponentially from 60 years of age onward,” they wrote.
The prevalence of young-onset dementia was similar in men and women, lower in the United States than in Europe, highest in upper- to middle-income countries, and highest for Alzheimer’s disease, followed by vascular dementia and frontotemporal dementia.
Monitoring the prevalence of young-onset dementia is “essential” to adequately plan and organize health services, the investigators noted.
To ensure more accurate prevalence estimates in the future, “efforts should be made to conduct more cohort studies and to standardize procedures and reporting of prevalence studies. In addition, more data are needed from low-income countries as well as studies that include younger age ranges,” they said.
New insights
In an accompanying editorial, David S. Knopman, MD, department of neurology, Mayo Clinic, Rochester, Minn., noted that the study provides new insights into an “underappreciated problem.”.
Young-onset dementia is a “particularly disheartening diagnosis because it affects individuals in their prime years, in the midst of their careers, and while raising families,” Dr. Knopman wrote.
“Most dementia care is geared for older patients, and as a consequence, services are rarely available to address the needs of someone diagnosed with dementia in their 50s who has dependent children at home and a spouse who must continue working. Understanding the prevalence and incidence of young-onset dementia is a first step in addressing this challenge,” Dr. Knopman wrote.
He noted that the authors of this analysis have “done a service to the dementia community by collecting and analyzing the dozens of individual studies of young-onset dementia.
“The product, a rationally derived estimate of dementia prevalence across the population aged 30-64 years, provides a basis for initiating more efforts to improve methods for timely diagnosis and to address the unique needs of patients with young-onset dementia,” Dr. Knopman concluded.
A version of this article first appeared on Medscape.com.