With dementia, over time, you stop being the ‘you’ that everybody knows.

The gradual loss of life-long memories and memory-related tasks isn’t the whole story.

And remember: To begin with, your memory slips appear to be in the normal range for an ageing person.

Forgetting why you entered a room, where you left the keys or even where you were headed to when driving aren’t necessarily signs you’re in trouble.

However, even before memory becomes an issue, certainly before you’ve been diagnosed, symptoms of dementia are in play.

Notably are changes in mood, behaviour and perception. Especially to people who know you.

Where did the money go?

One of the earliest symptoms, occurring years before memory or cognitive problems emerge, is money trouble.

You can see dementia in bank statements and other financial documents: Bills going unpaid late, subsequent loss of credit scores, penalty payments.

This is probably a matter of fading attention to life’s chores – apathy more than an actual memory problem.

Apathy is now recognised as a very early symptom.

But the money issue has a sinister dimension.

In 2011, the University of California San Francisco published a study that found that people with early dementia were unable to recognise sarcasm or when they were being lied to.

Neuropsychologist Katherine Rankin – a member of the UCSF Memory and Ageing Centre and senior author of the study – said that magnetic resonance imaging had showed associations between the deteriorations of particular parts of the brain and the inability to detect insincere speech.

“These patients cannot detect lies,” she said. “This fact can help them be diagnosed earlier.”

But it also leaves such people vulnerable to having their bank accounts emptied by scammers.

Adopting odd sleep patterns

Disrupted sleep is more common with age.

Even healthy older people sleep more lightly. They hit the hay earlier than they used to, and they wake up earlier.

However, according to a 2020 review, older adults have increased prevalence of primary sleep disorders including “insomnia, sleep-disordered breathing, restless legs syndrome, REM sleep behaviour disorder, and circadian rhythm disturbances”.

These can be “further compromised by sleep disturbances secondary to medical or psychiatric disorders, and medication side effects”.

Radical changes in sleep habits – having breakfast at 3am or sleeping all day – can be an early sign of dementia.

Joe Winer, an instructor of neurology and neurological sciences at Stanford University, recently told The New York Times: “Some of the brain regions, like in the brainstem, that are really important for regulating sleep and wake cycles are the first that are affected by Alzheimer’s disease.”

Frequently falling over

A 2022 study found that people with dementia have a higher incidence of injurious falls beginning four years leading up to diagnosis.

The researchers found that “the incidence of injurious falls in people with dementia peaks in the year of diagnosis”.

Katherine Rankin, of the UCSF Memory and Ageing Centre, earlier this year, in a widely reported overview of early dementia symptoms, said: “People will come into our office concerned because they forgot what was on their grocery list last week, but when their spouse says they’ve fallen four times in the past year, that’s a sign of a problem.”

Reduced gaze

‘Reduced gaze’ is the clinical term for when early dementia alters a people’s ability to move their eyes normally.

“We all move our eyes and track with them frequently,” Rankin said. “But people showing early signs of dementia look like they’re staring a lot.”

This can also show up as skipping lines when they try to read, and often looks like staring at a fixed point.

The person with dementia may not notice this, though the people around them certainly can if they’re paying attention.

 Personality changes

In 2016, at the Alzheimer’s Association International Conference in Toronto, a group of neuropsychiatrists and Alzheimer’s experts proposed a diagnostic checklist to identify personality changes that precede the thinking and memory problems of dementia.

“Has the person become agitated, aggressive, irritable, or temperamental?” the questionnaire asks.

“Does she/he have unrealistic beliefs about her/his power, wealth or skills?”

Just as people with early dementia fail to identify liars, they can also lose the ability to read social cues. This means they don’t understand why it’s not acceptable to say hurtful things.

This can be quite shocking when a person who was always caring and considerate is suddenly insensitive or rude.