Amyloid plaques and symptoms of depression links to medical help-seeking due to subjective cognitive decline

Abstract

<i>Background:</i> Subjective cognitive decline (SCD) is associated with an increased risk of Alzheimer’s disease (AD). However, patients reporting SCD to their general practitioner are not always referred to a memory clinic.<p>

<p><i>Objective:</i> To investigate whether prior history of medical help-seeking is associated with AD biomarker abnormality, worse cognitive performance, and/or depressive symptoms in SCD.<p>

<p><i>Methods</i>: We compared levels of cerebrospinal fluid (CSF) A<i>β</i>_{1 - 42}, cognitive performance, and depressive symptoms (15-item Geriatric Depression Scale, GDS-15) between healthy controls (<i>n</i> = 88), SCD with a history of medical help seeking (SCD-HS, <i>n</i> = 67), and SCD non help-seekers (SCD-NHS, <i>n</i> = 44). Cases with evidence of amyloid plaques (CSF A<i>β</i>_{1 - 42} ≤708 ng/l) and symptoms of depression (GDS-15≥6) were determined in both SCD groups.<p>

<p><i>Results</i>: The SCD-HS group had lower CSF A<i>β</i>_{1 - 42} (<i>p</i> < 0.01), lower word list learning and memory recall (p < 0.0001), and an increased level of depressive symptoms (<i>p</i> < 0.0001) compared to controls and SCD-NHS cases. The SCD-HS group had more cases with symptoms of depression (<i>n</i> = 12, 18%) and amyloid plaques (<i>n</i> = 18, 27%) compared to SCD-NHS (<i>n</i> = 1, 2% and <i>n</i> = 7, 16%, respectively). None of the SCD-HS cases and only one SCD-NHS case had concurrent symptoms of depression and amyloid plaques. The SCD-HS cases showed equal word list learning and memory performance regardless of amyloid status or symptoms of depression.<p>

<p><i>Conclusion</i>: Medical help-seeking in SCD is associated with an increased risk of AD pathology or symptoms of depression. However, subtle memory deficits are seen in SCD help-seekers, also without amyloid plaques or symptoms of depression.