Patients diagnosed with anxiety have an almost three times greater risk of developing dementia and it is a stronger risk factor than both depression and cerebrovascular disease, according to a UK primary care study.
The study’s authors suggest older patients could be presenting with anxiety which is caused by their first experiences of cognitive impairment.
Primary care researchers at Keele University in Staffordshire used the Consultations in Primary Care Archive to identify 400 cases of dementia and matched them to 1,353 controls without dementia.
After adjusting for various risk factors, a previous diagnosis of anxiety was independently associated with an almost threefold increase in risk of later dementia (odds ratio 2.7), compared with patients with no diagnosis of dementia.
This was higher than the increases in risk associated with cerebrovascular disease (OR 2.2) and a prior depression diagnosis (OR 1.54), although a diagnosis of depression and anxiety was associated with the highest risk of all (OR 2.9). Cerebrovascular disease is a well known risk factor for the development of dementia and previous research has suggested a diagnosis of depression is also a risk factor.
But this is the first study to look in detail at an association between anxiety and dementia, while adjusting for a diagnosis of depression. It is also the first to suggest anxiety is such a strong risk factor.
NICE guidelines on dementia mention vascular risk factors, but not mental health disorders as being risk factors.
The SIGN guideline on dementia states that ‘the presence of comorbid depression’ should be considered as part of an assessment for suspected dementia, but does not include anxiety in its recommendations.
Study lead Dr Claire Burton, a GP and research fellow at the department of primary care and health sciences at Keele University, says: ‘It seems reasonable to postulate that – as with depression – patients may present with anxiety symptoms as a direct cause of the insight they have into their early experiences of cognitive impairment.
‘One possible course of action would be to include a screen for cognitive impairment in the routine follow-up of older patients with anxiety and depression and incorporate this in the QOF.’
Dr Kate Thomas, a GPSI in mental health in Glasgow who runs a community memory clinic, said: ‘This suggestion of a stronger association with anxiety is important to know and it’s certainly reasonable to use the MMSE in older patients presenting with anxiety.’
Family Practice2012, online