How to spot the first early signs of Alzheimer’s and dementia

Finally – after many false dawns – an effective new drug for Alzheimer’s is on the horizon. In early May, US scientists announced that the drug donanemab delays the worsening of symptoms by 35 per cent. Half the patients on the trial found their mental decline was halted for more than a year. 

The Alzheimer’s Society went as far as describing the results as: “the beginning of the end for Alzheimer’s disease”.

There a still few hurdles to jump before donanemab becomes available in the UK. But even when it does arrive, scientists insist that early diagnosis – by watching out for subtle symptoms – is still key.

In February, scientists announced a new blood test that could predict dementia up to 15 years earlier. The new test, the result of a study by the University of Warwick, looks for proteins in the blood and can pick up signs that the prescriptions of drugs such as donanemab - or lecanemab, a similar medication - would be appropriate.

It’s well known that memory loss and confusion are a sign of dementia. But scientists are discovering that other subtle – and perhaps surprising – signs can herald the onset of the disease. For example, in October, UCL researchers found that people who wandered off course walking on a well-known triangular route, might be showing early signs of dementia.

These smaller and quieter clues occur in our daily lives, making them fairly easy to identify – if you know what to look out for. With our senses being linked to the brain, it’s not surprising that occurrences, such as those relating to our eyesight or hearing, could be signs of early dementia.

However, it is also key to understand that some of these changes, such as mood or occasional moments of forgetfulness, can simply be signs of old age - which are not as concerning.

Read below for the quiet, early signs of dementia  – and some advice on how to prevent their progression.

What signs and symptoms of dementia should you look out for?

Eye conditions and hearing loss

People who develop certain eye conditions are at increased risk of dementia, according to research from 2021. A UK Biobank study of 12,000 midlifers found those with age-related macular degeneration were 25 per cent more likely to develop dementia. Those with cataracts had an 11 per cent increased risk of dementia, and those with diabetes-related eye disease had a 61 per cent per cent heightened risk of dementia.

The study follows research from 2021 by the University of Oxford that suggested people who go out for a meal at a noisy restaurant but are unable to hear what their friends are saying may be at an increased risk of developing dementia. The data from the study suggests that age-related hearing loss might be related to the onset of Alzheimer’s and other conditions. 

“While preliminary, these results suggest speech-in-noise hearing impairment could represent a promising target for dementia prevention,” says Thomas Littlejohns of the Nuffield Department of Population Health at Oxford and a lead author of the study. 

Katie Puckering is information services manager for Alzheimer’s Research UK. “There are two reasons for this potential link,” she says. “The first is that hearing loss might be linked with cellular changes in the brain. But the second is that social isolation has long been known as a risk of Alzheimer’s and other forms of dementia.”

Something as simple as having your hearing checked out – and having a hearing aid fitted, if needed, so you can hear the conversations around you – could lower your risk of dementia. This is known as a modifiable risk – that is, one that you can change or control.

In 2017, the Lancet Commission on Dementia found that 12 modifiable risks – one being hearing loss – could lower the number of dementia cases by 40 per cent. Others included lack of physical activity, obesity and low educational attainment.

“Mild cognitive symptoms can begin 15 to 20 years before the onset of dementia,” says Puckering. “If it’s picked up early enough, a doctor can refer you to a memory clinic for further tests or point you in the direction of research trials.”

Breakthrough medical treatments are starting to appear, such as medications aducanumab and Lecenamab, which has been licensed in the US and is pending approval in the UK.

“Early intervention gives you the best chance,” says Puckering. “At the very least, this will allow you to plan ahead.”

Withdrawing from hobbies or family

“It’s common in midlife to have periods of low motivation, or feeling less sociable than usual,” says Puckering. 

“But if you find yourself consistently becoming more confrontational than usual, or regularly snapping at your family, you may want to see a doctor to rule out other conditions including menopause, a mood disorder such as depression, a thyroid condition or even a vitamin deficiency.”

Others in the family may notice these changes before the person themselves. 

Not understanding sarcasm or sense of humour

“Early signs of dementia include changes to language, behaviours and responses to social cues,” says Hannah Churchill, research communications manager at Alzheimer’s Society.

According to a 2017 report in the Journal of Neurology, Neurosurgery and Psychiatry, individuals with early dementia laughed less both at their own jokes and other people’s funny comments than those who did not. This followed a 2009 report that, following MRI scans, those with neurodegenerative disease images were less able to recognise sarcasm. 

“If you find your sense of humour has changed significantly, it might be worth getting some medical advice,” says Puckering.

Forgetting what things are called or what they are for

Regularly not being able to remember your own phone number, and finding it hard to organise your own thoughts: both of these may be warning signs. “Much is made of keeping your brain active, doing puzzles and so on,” says Puckering. “But in fact, physical fitness is more important. What’s good for the heart is also good for the brain: 80 per cent of our brain is oxygen, and if you starve the brain of oxygen, it won’t do well.” 

Experts suggest 150 minutes of moderate to vigorous exercise a week, a healthy diet, and keeping conditions such as type 2 diabetes and high blood pressure under control.

Gum disease

“The evidence linking oral health or gum disease and an increased risk of cognitive decline or dementia is mixed,” says Churchill. It could simply be that people who have received better dental care during their lifetime may have enjoyed a healthier lifestyle, which tends to be associated with reduced dementia risk. 

But a growing body of research, including a 2019 study in the Journal of Periodontology, has shown that periodontal (gum) disease and poorly fitting dentures can be a risk factor for dementia. 

Ensure you stick to basic oral hygiene, brushing your teeth twice a day, with a fluoride-containing toothpaste, see your dentist every six months, and don’t be put off dental procedures.

Change in mood

Research from 2011 in the Archives of General Psychiatry showed that symptoms of clinical depression doubled the risk of cognitive impairment in older women and quadrupled it in men – and could even be a precursor to Alzheimer’s. 

“Scientists have long known that depression and dementia go hand in hand,” says Dr Cornelia Cremens, assistant professor of psychiatry at Harvard Medical School. “If somebody appears to have the beginnings of dementia and they are depressed, it’s very important to treat their depression, and to treat it as aggressively as possible.”

Ask your GP about a referral for talking therapy such as CBT, or, if appropriate, antidepressant medication. Puckering says: “Your GP may tell you you ‘only’ have depression, but it’s important to find a treatment for your distress, whether it’s a mood disorder, or an early sign of dementia.”

When not to worry: age-related changes that can happen to us all

• Sometimes forgetting names or appointments, but remembering them later
• Occasionally needing help with oven settings or the TV remote control
• Misplacing things from time to time, and retracing your steps to find them
• Making the occasional bad decision, like running out of petrol
• Becoming irritable if your routine is disrupted

This article is kept updated with the latest information.