Hidden dementia warning sign can show up 15 years before diagnosis, according to study

There's one key indicator of dementia that can develop more than a decade prior to diagnosis, according to experts who tracked more than 7,000 people over 12 years.

Dementia is often a condition we associate with older age, but patients can start to develop symptoms at any age, although rarer the younger the person is.

According to Dementia UK, when symptoms develop before the age of 65, it is known as young-onset (or early-onset) dementia.

And while rare, accounting for about 5% of all cases, it can affect people in their 40s, 30s, and rarely even in their 20s or teen years.

But as per a new study conducted by researchers in Finland, there's one key indicator that points health experts towards a person being diagnosed with the cognitive condition in the years to come.

The scientists noted that monitoring professional performance and changes in earnings throughout a person's life, could help identify the condition up to 15 years earlier than current diagnostic methods permit.

The study revealed that on average, individuals with early-onset dementia earned $13,800 less per year than those without, starting a decade and a half before their diagnosis.

But over time, the productivity drop resulted in an estimated loss of roughly $86,000 in total wages per patient.

While it's commonly associated with older people, the condition can be diagnosed at any age. (Getty Stock Images)

Dr. Eino Solje, a neurologist who led the research, explained: "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.

"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."

Patients can experience an array of different symptoms. (Getty Stock Images)

Following the research, Solje urged that future research should include neuropsychological tests to track changes in cognition over time, and pushed for interventions to be developed that could prevent or delay productivity decline.

Common symptoms of early-onset dementia include difficulty remembering scheduled appointments, struggling to perform everyday tasks that they previously handled successfully, and finding it hard to concentrate or follow ordinary conversations.

But as time progresses, many patients will experience severe mood swings, confusion regarding time and location, and uncharacteristic suspicion toward friends and family members.

Currently, there is no cure for dementia, but there are medications available that can help slow down its progression.