It can leave people with a racing heartbeat and dreading work meetings.

But a new study has found that living with anxiety may also radically raise a person's risk of developing dementia.

Adults over 60 diagnosed with anxiety in the last 10 years were about three times more likely to develop dementia than those without the condition.

And those who were diagnosed with anxiety before age 70 had even worse odds, as they were up to seven times more likely to develop dementia.

The team believes that this could be due to patients with mental illness being more likely to engage in risky behaviors like smoking and eating a poor diet, which have been shown to lead to dementia. 

Some evidence also suggests that anxiety causes excess levels of stress hormones, leading to inflammation in the brain that releases toxins and slows cognitive function, resulting in dementia. 

The study adds to a growing body of research suggesting that mental health could be tied to cognitive impairment. 

The researchers wrote: 'To our knowledge, this is the first study assessing the effect of persistence of anxiety (chronic vs resolved vs new anxiety) and the timing of exposure to anxiety on dementia risk.' 

'These results suggest the possibility of anxiety as a modifiable risk factor for dementia and the timely management of anxiety helps to reduce the risk of dementia.'

According to the National Institute of Mental Health, just under one in five US adults have an anxiety disorder. This adds up to 40million Americans.  

The researchers evaluated 2,132 participants above age 60. The majority (53 percent) were female. 

Most of the Australians included in the study had completed at least a trade school education and had a history of tobacco smoking. 

On average, 62 percent of participants consumed one to four alcoholic beverages per week.  

Patients were divided into three groups based on age: 60-70, 71-80, and 81+. The average participant age was 76. 

Anxiety was measured once at the start of the study (wave 1) and again after five years (wave 2). 

Patients with 'chronic' anxiety showed symptoms at the beginning and end of the experiment, while those who were just anxious at the beginning had 'resolved' anxiety. Meanwhile, patients who only displayed symptoms toward the end had 'new' anxiety.

Over the 10-year study period, roughly three percent of participants developed dementia and seven percent died.

The researchers found that, on average, participants with chronic anxiety were 2.8 times more likely to develop dementia, and those with new anxiety were 3.2 times more likely. 

However, the likelihood was greatest for those under 70.

Patients 60 to 70 with chronic anxiety were 4.6 times more likely to develop dementia, which ballooned to 7.2 times for those in that age group with new anxiety. 

The team said this could be because having anxiety at younger ages has been shown to increase the risk of heart disease and other issues over time that have been linked to dementia. 

But the study also showed that participants whose anxiety was cured between waves 1 and 2 were not at any increased risk, showing that treatment through therapy and medication was effective in lowering risk. 

'In our study, the risk of dementia among resolved cases were similar to those without anxiety,' the researchers wrote. 

'These findings support anxiety as a potential modifiable risk factor for dementia and point to the possible role of managing anxiety in middle aged and “young” older adults to reduce the risk of dementia in later life.'

Anxiety is typically treated with a mix of therapy, medications, and lifestyle changes, though each patient is different.  

'People with anxiety are more likely to engage in unhealthy lifestyle behaviors including unhealthy diet, physical inactivity, and smoking, which in turn can lead to cardiovascular disease, which is strongly associated with dementia,' the team wrote.

'Therefore, these are plausible direct and indirect mechanisms by which anxiety can increase the risk of dementia.' 

There were several limitations to the study, including cases potentially being found after initial disease onset and only assessing anxiety symptoms within four weeks of each check-in. 

The team also 'did not have information regarding how the anxiety was resolved' at the end of the experiment. 

The researchers believe that lifestyle factors common in people with anxiety could explain the increased risk. 

The study was published Wednesday in the Journal of the American Geriatrics Society. 

WHAT IS DEMENTIA?

A GLOBAL CONCERN 

Dementia is an umbrella term used to describe a range of progressive neurological disorders (those affecting the brain) which impact memory, thinking and behaviour. 

There are many types of dementia, of which Alzheimer’s disease is the most common.

Some people may have a combination of different types of dementia.

Regardless of which type is diagnosed, each person will experience dementia in their own unique way.

Dementia is a global concern but it is most often seen in wealthier countries, where people are likely to live into very old age.

HOW MANY PEOPLE ARE AFFECTED?

The Alzheimer's Society reports there are more than 900,000 people living with dementia in the UK today. This is projected to rise to 1.6 million by 2040.

Alzheimer's disease is the most common type of dementia, affecting between 50 and 75 per cent of those diagnosed.

In the US, it's estimated there are 5.5 million Alzheimer's sufferers. A similar percentage rise is expected in the coming years.

As a person’s age increases, so does the risk of them developing dementia.

Rates of diagnosis are improving but many people with dementia are thought to still be undiagnosed.

IS THERE A CURE?

Currently there is no cure for dementia.

But new drugs can slow down its progression and the earlier it is spotted, the more effective treatments can be.

Source: Alzheimer’s Society