Anxiety is associated with increased risk for cognitive decline and dementia, according to a meta-analysis published in the American Journal of Geriatric Psychiatry.
B. Gulpers and colleagues, from Maastricht University Medical Center in the Netherlands, conducted a systematic literature search up to January 2015 to identify all longitudinal studies on the association between anxiety and cognition. The authors included both community studies and studies of patients being evaluated in memory clinics for conversion to dementia. Twenty studies met inclusion criteria.
The researchers found that, in 4 studies, anxiety predicted incident cognitive impairment in the community (n=4 155 patients, risk ratio [RR], 1.77; P < 0.001). Incident dementia was found to predict cognitive impairment in six studies (n= 6 004 patients, RR = 1.57; P = 0.04). The association between anxiety and dementia was stronger among individuals aged 80 years and older, compared to those younger than 80 years (RR = 1.21; P = 0.20). However, among cases of clinical MCI in patients recruited at memory clinics, the link between anxiety and the conversion to dementia was not statistically significant. The authors speculated that this might be a result of referral bias.
Given that strong association between anxiety and MCI was driven by higher age, the authors suggested that anxiety might be a prodromal symptom.
One of the reasons the authors undertook a study of anxiety is the MCI is an important risk factor for dementia, and anxiety and depression often present together with MCI. They noted that most research has focused on depression. “Studies are scarce and vary in methodology, especially according to the setting and stage of the neurodegenerative process.”
They emphasized that whether or not the association is causal, “it is important for the clinician to be aware of anxiety as a possible predictor for dementia, especially when the anxiety emerges at late life.”
They described their study as having “some important strengths”—ie, through the inclusion of both community and clinical studies, the risk of referral bias was minimized. They referred to their study as “the most comprehensive account of the current evidence base possible at this moment,” adding that future studies should investigate whether neuropsychiatric symptoms (eg, apathy and depression) “are all independent risk factors, or whether they are an expression of a latent underlying variable.”
Gulpers B, Ramakers I, Hamel R, et al. Anxiety as a predictor for cognitive decline and dementia: a systematic review and meta-analysis. Am J Geriatr Psychiatry. 2016. doi: 10.1016/j.jagp.2016.05.015.