Elevated amyloid deposition in cortical and subcortical brain regions is associated with higher depressive and anxiety symptoms in people without dementia, according to a cross-sectional observation published in The Journal of Neuropsychiatry and Clinical Neurosciences. Given the association between amygdala and emotion, the authors wanted to investigate the association between depression and anxiety and certain brain regions.
The researchers used the Mayo Clinic Study of Aging in Olmsted County, Minnesota. They included people without dementia age 70 or older who went through neurological evaluation, risk factor ascertainment, and neuropsychological testing, as well as Pittsburgh Compound B positron emission tomography (PiB-PET), to assess Aβ deposition in cortical and subcortical regions.
Patient data spanned from January 2006 through October 2018. The sample included 842 individuals without cognitive impairment and 180 persons with mild cognitive impairment.
The researchers found a positive association between cortical Aβ deposition, as well as Aβ deposition in the amygdala, striatum, and thalamus, and depressive and anxiety symptoms in community-dwelling older adults without dementia. Each 1% increase in cortical PiB-PET standardized uptake value ratios (SUVRs) corresponded subtle increases in BDI-II total score and BAI total score.
“Subcortical Aβ deposition may indicate more advanced amyloidosis beyond the cortex and may be regarded as a marker of pathologic progression,” the authors noted.
Individuals with mild cognitive impairment showed an association between Aβ deposition in the neocortex, amygdala, striatum, or thalamus and depressive symptoms, but not anxiety.
The researchers were unable to assess causality. The severity of depression and anxiety symptoms were low in the community-dwelling older adults analyzed. Thus, the small variance may reduce the significance of the association.
The authors suggest a prospective cohort study to build on their findings.
Krell-Roesch J, Syrjanen JA, Rakusa M, Et al. Association of cortical and subcortical β-amyloid with standardized measures of depressive and anxiety symptoms in adults without dementia. J Neuropsychiatry Clin Neurosci. 2020;Oct22:appineuropsych20050103. doi: 10.1176/appi.neuropsych.20050103