Your work performance may reveal early signs of brain disease up to 15 years before diagnosis, scientists find

A gradual drop in work performance could be one of the earliest signs of early-onset dementia, long before a person or even doctors realise something is wrong, according to a new study from Finland. The findings suggest that changes in productivity and earnings may begin up to 15 years before a formal diagnosis, offering a possible way to spot the condition much earlier than is currently possible.

The research was published on July 8 in Neurology, the medical journal of the American Academy of Neurology.

Declining work productivity linked to early-onset dementia

Researchers followed 793 people diagnosed with early-onset dementia and compared them with 7,926 people of the same age and sex who did not have the condition. The team tracked their work history and earnings over a 12-year period before diagnosis.


Early-onset dementia refers to dementia diagnosed before the age of 65. Although it is less common than dementia in older adults, it can affect people in their 40s, 30s and, in rare cases, even younger individuals. According to Dementia UK, it accounts for around five per cent of all dementia cases.

The study found that people who later developed early-onset dementia were earning an average of about $13,800 less per year than those without the condition. Over time, those losses added up to around €74,577, or roughly $86,000, per person.

Researchers say changes begin years before diagnosis

Dr. Eino Solje, the neurologist who led the study, said the findings show that work-related changes may appear long before a diagnosis is made.

"Early-onset dementia affects people during their most productive years and is associated with a decreased ability to work, increased unemployment and leaving jobs sooner than planned."

He added, "These changes can reduce household income and contribute to broader economic impact. Our study found an association between reduced work productivity and early-onset dementia up to 15 years before diagnosis."

Dr. Solje also said, "These findings may partly be explained by delays in diagnosis, which can prolong the period of unrecognized symptoms, and they underscore the harmful, long-term socioeconomic impact of early-onset dementia."

The researchers believe future studies should include neuropsychological testing over time to better understand cognitive decline and explore ways to prevent or delay the loss of productivity.

The pattern differed across dementia types

The study also found that the timing of productivity decline varied depending on the type of dementia.

For people who were later diagnosed with Alzheimer's disease, lower productivity became noticeable around six years before diagnosis. Those who developed frontotemporal dementia showed signs nearly 11 years earlier. In people with alpha-synucleinopathies, which include dementia with Lewy bodies and Parkinson's disease dementia, the decline became clear only around the time of diagnosis.

People with vascular dementia and mixed dementias showed consistently higher productivity losses throughout the period studied.

Experts say workplace changes should not be ignored

Commenting on the findings, Dr. Edmundo Rodriguez-Frias, medical contributor at Full of Life, a recovery centre in New Jersey, told Newsweek that the research supports what many specialists have already observed.

"This study is significant as it supports what many dementia experts have observed in clinical practice."

He added, "Cognitive decline likely occurs for several years prior to receiving the official diagnosis of a cognitive disorder. The first sign of such cognitive decline could potentially be a noticeable decline in job performance, especially for those diagnosed with early-onset dementia who are still working."

He further said, "This research shows the value of recognizing early signs of potential problems. If a previously high-functioning individual develops persistent difficulty with planning, task management, making decisions, language use, or adapting to new tasks, especially if others also notice these changes, it may be worth talking to your doctor instead of dismissing the problem as normal aging or work-related stress."

Common symptoms to watch for

Many people with early-onset dementia first notice problems while at work. They may begin forgetting appointments, struggle with tasks they had previously done without difficulty, or find it harder to concentrate and follow conversations.

As the disease progresses, symptoms can become more severe. These may include confusion about time and place, major mood changes and increasing suspicion towards family members or friends.

There is currently no cure for dementia, but treatments are available that may help slow the progression of the disease. Researchers say recognising warning signs earlier could improve access to support and care while also reducing the personal and financial impact of delayed diagnosis.