An analysis of the available published evidence in the online journal BMJ Open suggests that moderate to severe mid-life anxiety may be linked to dementia in later life. However, it remains unclear as to whether active treatment could curb this risk. Moreover, the degree to which non-drug therapies such as meditation and mindfulness that reduce anxiety might help is unknown also.
A number of studies have indicated that mental illness – such as anxiety, depression or eating disorders – might be associated with dementia in older age. However, it’s not clear if this mental illness factor represents initial (prodromal) symptoms before the advent of fully fledged disease, or if it acts as an independent risk factor.
To this end, the researchers carefully examined research databases for studies looking at the association between mid-life anxiety, in isolation or combined with depression, and the development of dementia. They discovered only four out of more than 3500 studies that met these criteria. However, these four studies involved a total of nearly 30,000 people. All four studies were of high quality and were sufficiently peer-reviewed, despite differing study designs between them which excluded the possibility of pooled analysis of the data.
Each study accounted for a range of potentially influential factors, such as age demographic, physical health, and psychological health, and all found an association between moderate to severe anxiety and future dementia. For each study, there was a gap of at least 10 years in between diagnoses.
According to the researchers, these findings reinforce recent evidence pointing to a link between anxiety and risk of mild cognitive impairment, and lend weight to the known association between depression and dementia.
How does this work?
Moderate to severe anxiety provokes an abnormal stress response, which in turn may speed up brain cell ageing and degenerative changes in the central nervous system. This mechanism might feasibly increase one’s vulnerability to dementia.
What can we do about it?
Further research might examine whether reducing anxiety in middle age would result in reduced risk of dementia. The researchers suggest that approaches other than anti-anxiety drugs may be worth testing, including talking therapies, mindfulness-based interventions and meditation practices. “Although this is yet to be thoroughly researched,” the researchers caution. However, they suggest that given the prevalence of anxiety, it may be worth doctors considering anxiety a risk factor for dementia as well as depression.
You can read more about this study here.