Anxiety in Middle Age Linked to Dementia in New Study

Moderate to severe anxiety has been linked to dementia in a new study. Researchers set out to build on previous studies which have suggested that mental illness may be associated with dementia in those aged over 65.

The team at University College London and the University of Southampton wanted to understand whether moderate to severe anxiety is a precursor to dementia, or whether it is a risk factor.

Dementia is an umbrella term for diseases characterized by cognitive decline, with Alzheimer's being the most common. Those with the condition usually first show signs after the age of 60. The latest U.S. figures from 2013 show that 5 million Americans were living with Alzheimer's disease at the time, a figure expected to rise to 14 million people by 2050.

The cause of dementia remains unknown, although scientists believe that age, genetics, educational attainment, diet and one's environment could play a part.

To investigate their hypothesis, the team analyzed data from existing studies on participants who reported experiencing anxiety between the ages of 30 and 65, both on its own and in combination with depression. The researchers made note of the participants who were diagnosed with dementia on average at least a decade after being assessed for anxiety. The research involved almost 30,000 participants.

Moderate to severe anxiety was found to be linked with the onset of dementia in later life. While feeling anxious in appropriate situations is normal, anxiety disorders are characterized by such feelings debilitating a person's life. Such conditions include Generalized Anxiety Disorder, Panic Disorder, and Social Anxiety Disorder, with symptoms ranging from intense feelings of fear to physical symptoms such as dizziness and muscle tension.

A couple look across the landscape at Lands End, San Francisco. A new study has investigated the potential link between anxiety and dementia. Matthew Bennett/Unsplash

The team behind the study published in the journal BMJ Open believe that the stress response anxiety causes in the body could make brain cells age faster, and trigger degenerative changes in the central nervous system. In turn, this could make a person more vulnerable to developing dementia. They were not able to find a direct causal link, however.

The authors also stressed that it is unclear whether reducing anxiety in middle age would result in a reduced risk of dementia. Further research is needed to understand whether treatment for anxiety, including drugs, talking therapies and mindfulness-based interventions and meditation practices proven to ease anxiety in midlife, could reduce the risk of dementia.

Dr. Natalie Marchant, lead author of the study and senior research fellow at University College London Faculty of Brain Sciences, told Newsweek: "Given the long time interval between the assessment of anxiety and the diagnosis of dementia (on average greater than 10 years), the findings from our review indicate that moderate to severe anxiety in mid-life may be a potentially modifiable risk factor for dementia. This research shows an association between anxiety and dementia, not that anxiety causes dementia. More research is needed to understand this relationship."

"We certainly do not want to create more worry for people already experiencing anxiety. If people are living with moderate to severe anxiety there are therapies available that can help, for example talking therapies and mindfulness-based interventions. While we do not yet know whether these therapies would also reduce risk of developing dementia, treating anxiety is important in its own right for maintaining mental health."

Dr James Pickett, head of research at Alzheimer's Society which part-funded the study, commented in a statement: "Currently, we don't know enough about anxiety to say whether it is an early sign of the changes in the brain seen in dementia, or if it independently puts people at greater risk of developing the condition.

Read more: College-Educated People Develop Dementia Later in Life, Study Suggests

"What we do know is that changes in the brain can begin more than 10 years before dementia symptoms emerge. As well as anxiety, there are other complex mental health issues that can be seen in the early stages of dementia, and we need further research to unpick the relationship between these."

Dr Sara Imarisio, head of research at the charity Alzheimer's Research UK who was not involved in the study, said in a statement: "Much more research is required to understand the mechanisms underpinning this link, and to see if different forms of anxiety treatment could have any effect on dementia risk. Anyone who is concerned about their mental health they should seek advice from their doctor.

"Mental health conditions like anxiety and depression have been linked to dementia before and many overlapping symptoms make a dementia diagnosis difficult. This review took a high-quality approach, combining findings from four existing studies exploring anxiety as a risk factor for dementia. This approach revealed a link between anxiety in midlife and dementia, but large differences between the individual studies meant researchers were unable to comprehensively analyse the results."

It's important to remember that just because there is an association between the two factors does not necessarily mean that anxiety causes dementia," she said, explaining that dementia is caused by a complex mix of risk factors including ageing and genetics. We know the diseases leading to dementia can begin in the brain up to twenty years before any symptoms show," said Imarisio.