Recent analysis of data from 13 previously published studies of more than 30 000 people has highlighted a major gap that often keeps people from getting early treatment and support for dementia, and showing it takes an average of 3.5 years to diagnose the condition after symptoms begin, and even longer for early-onset cases.
The scientists – led by University College London – said that early dementia symptoms can be subtle or are often mistaken as signs of normal ageing, which delays diagnosis and access to care, reports Everyday Health.
Getting diagnosed early can open the door to new treatments and support services, and give people time to plan for the future, they said.
Their research, which looked at data from studies of people across Europe, the United States, Australian and China, found it takes around 3.5 years for a person with dementia to receive a diagnosis after experiencing the first symptoms, and for those with early-onset dementia, the delay is even longer: 4.1 years.
Senior study author Vasiliki Orgeta, PhD, an associate professor of psychiatry at University College London, said the findings highlight the urgent need to improve public awareness and training for healthcare providers and to streamline the referral process.
Why the delay?
Unfortunately, it’s not surprising that diagnosis takes so long, especially in younger people, said David Reuben, MD, director of the UCLA Alzheimer’s and Dementia Care programme in Los Angeles.
“People who are younger and have atypical presentations often tell me they spent five years trying to find out what was wrong with them,” said Reuben, who wasn’t involved in the study.
A big factor is that many types of dementia, including Alzheimer’s disease, are age-related diseases, which means symptoms can be subtle and are often mistaken for normal signs of ageing.
“For example, at 65 to 70, Alzheimer’s affects about 3.5% of the population. So if somebody’s 65 and they say they are having memory problems, it’s unusual for them to have dementia. But once you get to 90, it’s almost one-third of the population.”
Symptoms
Orgeta said the early symptoms of dementia include:
- Memory problems;
- Trouble finding words;
- Getting confused in familiar places; and
- Struggling with everyday tasks.
“Some people may also show changes in mood or behaviour,” she added. These signs usually start to appear in people over 65, but for some, especially those with young-onset dementia, symptoms can begin as early as their 40s or 50s, she said.
How to tell whether forgetfulness is due to dementia or normal ageing
“It can often be challenging to recognise, especially in the early stages. Occasional forgetfulness can be part of normal ageing,” said Arman Fesharaki-Zadeh, MD, PhD, an assistant Professor of Psychiatry and neurology at the Yale School of Medicine in Connecticut, who wasn’t involved in the study.
Screening can help, but it may miss people whose symptoms are more subtle.
“The best way to know for sure is to get a neuropsychological evaluation in which the individual’s cognitive abilities are measured against what is normal for people of their age and education level,” said Stephanie Towns, PsyD, a neuropsychologist and associate Professor of Neurology who also works at the Yale School of Medicine.
Can early diagnosis make a difference?
Early diagnosis is proving to be crucial, as is prevention, said Maryjo Cleveland, MD, an Alzheimer’s researcher and physician specialising in dementia management and frailty at Atrium Health Wake Forest Baptist in North Carolina.
“We know now that people with normal cognition, who eat a healthy diet, get a significant amount of exercise, are cognitively and socially engaged, and who control their blood pressure, can delay cognitive decline,” said Cleveland, who was not involved in the study.
“People who get a diagnosis of mild cognitive impairment or early Alzheimer’s may be eligible for the new anti-amyloid treatments that can delay the progression of the disease,” she said. Those include Kisunla (donanemab) and Leqembi (lecanemab), both approved to treat early Alzheimer’s disease or mild cognitive impairment.
The other benefit of an early diagnosis is that it gives you time to plan for the future, Reuben said.
Study details
Time to diagnosis in dementia: a systematic review with meta-analysis
Olubunmi Kusoro, Moïse Roche, Rafael Del-Pino-Casado, Phuong Leung, Vasiliki Orgeta.
Published in International Journal of Geriatric Psychiatry 27 July 2025
Abstract
Timely dementia diagnosis is a global priority, reflected in most national and regional policies and plans. Nevertheless, there are currently no robust estimates of the average time to diagnosis (TTD) and factors influencing diagnostic intervals. This article presents the first systematic review of quantitative studies on TTD in dementia and the factors associated with its duration. We systematically searched EMBASE, Psych INFO, MEDLINE, and CINAHL databases for relevant studies published up to December 2024. We defined TTD as the interval between symptom onset (rated by family carers or patients using interviews or medical records) to final diagnosis. Risk of bias was assessed using the Reporting studies on time to diagnosis tool. We included 13 studies reporting data on 30 257 participants, with age at onset ranging between 54 and 93 years. Meta-analysis pooling 10 studies showed that average mean TTD across all types of dementia was 3.5 years [confidence interval (CI): 2.7–4.3; moderate quality evidence]. Analyses of six studies showed that TTD in young onset dementia was 4.1 years (CI: 3.4–4.9; moderate quality evidence). Although the factors influencing TTD were inconsistent, a younger age at onset and having fronto-temporal dementia were consistently associated with a longer interval to diagnosis. TTD in dementia remains long, and specific healthcare strategies are urgently needed to improve it. Increasing the evidence base and developing interventions to reduce TTD should be a future research priority. Specialist services are likely to be key in improving TTD in young-onset dementia.
Everyday Health article – Dementia Takes More Than 3 Years to Diagnose, Research Finds (Open access)
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New blood test shows ‘remarkable’ promise in the diagnosis of Alzheimer’s
Dementia diagnosis and life expectancy – Dutch review
Four in 10 dementia cases could be prevented or delayed — Lancet Commission