The surprising early sign of dementia that may appear up to 15 years before diagnosis
Most people think memory loss is the very first sign of dementia.
But new research suggests that changes in work performance and productivity may begin many years before a diagnosis is ever made, particularly in people with early-onset dementia.
The findings highlight just how gradually dementia can develop, and why recognising subtle changes early may help people seek medical advice sooner.
While becoming less productive at work doesn't automatically mean someone has dementia, experts say it may be one piece of a much larger puzzle.
What is early-onset dementia?
Early-onset dementia refers to dementia diagnosed before the age of 65.
Although it's less common than dementia in older adults, it can have a significant impact because it often affects people during their careers, while they're raising families and managing busy lives.
Unlike typical age-related memory decline, early-onset dementia can interfere with thinking, decision-making, planning, language and behaviour years before a formal diagnosis.
The study that caught researchers' attention
Researchers in Finland followed 793 people with early-onset dementia and compared them with more than 7,000 healthy adults.
Their findings, published in the journal Neurology, showed that people who later developed early-onset dementia experienced reduced work performance many years before diagnosis.
On average, researchers found:
- Reduced earnings began up to 15 years before diagnosis
- People were more likely to struggle with productivity at work
- Earlier retirement and unemployment became increasingly common
- Household income gradually declined over time
Researchers believe these workplace changes may reflect subtle changes in brain function that develop long before dementia is recognised.
Importantly, this research shows an association, not proof that reduced work performance causes or predicts dementia.
Early signs of dementia that shouldn't be ignored
Many of the earliest symptoms aren't dramatic memory lapses.
Instead, they may include:
- Difficulty concentrating
- Taking much longer to complete familiar tasks
- Forgetting appointments
- Repeating questions
- Struggling to follow conversations
- Difficulty planning or organising
- Making more mistakes than usual
- Feeling overwhelmed by tasks that once felt easy
These symptoms can also be caused by stress, menopause, burnout, anxiety, depression, poor sleep or other medical conditions, which is why it's important to speak with your GP if changes persist.
Why early diagnosis matters
There is currently no cure for dementia, but an earlier diagnosis allows people to:
- Access treatments sooner
- Manage symptoms more effectively
- Make lifestyle changes that may help protect brain health
- Plan for the future
- Receive support for themselves and their families
For younger adults, early diagnosis can also help explain changes that may have been affecting work or relationships for years.
Can you reduce your risk of dementia?
While age and genetics play a role, research suggests that up to 45% of dementia cases worldwide may be linked to potentially modifiable lifestyle factors, according to the 2024 Lancet Commission.
Healthy habits that support both brain and overall health include:
Stay physically active
Regular exercise, particularly strength training combined with aerobic activity, improves blood flow to the brain and is consistently associated with a lower risk of cognitive decline.
Eat a brain-friendly diet
A Mediterranean-style eating pattern rich in vegetables, fruit, legumes, nuts, olive oil, fish and whole foods has been linked to better brain health and a lower dementia risk.
Prioritise sleep
Poor sleep has been associated with an increased risk of cognitive decline. Aim for 7-9 hours of quality sleep most nights.
Keep your brain active
Learning new skills, reading, puzzles, social engagement and lifelong learning all help keep the brain challenged.
Look after your heart
High blood pressure, diabetes, obesity, smoking and high cholesterol are all linked with an increased risk of dementia.
Support your gut health
Emerging research suggests the gut-brain connection may influence inflammation and brain function. Eating a fibre-rich diet that supports a healthy gut microbiome may also benefit long-term brain health.
Consider creatine
While creatine is best known for supporting muscle health, emerging research suggests it may also help support brain energy metabolism, particularly during periods of mental fatigue or sleep deprivation. More research is still needed, but it's an exciting area of study.
This new research doesn't mean that having a difficult year at work is a sign of dementia.
However, persistent changes in concentration, decision-making, memory or productivity, particularly when they worsen over time, shouldn't be ignored.
If you or someone you love has noticed ongoing cognitive changes, it's worth speaking with your GP. Many conditions, including menopause, thyroid disorders, vitamin deficiencies, depression and sleep problems, can mimic dementia symptoms and are often treatable.
The earlier a cause is identified, the sooner you can access the right care and support.