Cognitive impairment in remitted late-life depression is not associated with Alzheimer's disease-related CSF biomarkers

Abstract Background Cognitive impairment is a common feature of late-life depression (LLD). Early studies using Alzheimer's disease (AD) biomarkers inferred a biological link between AD pathology and LLD, but recent findings have challenged this association. The aim of this investigation was to determine a panel of AD-related cerebrospinal fluid (CSF) biomarkers in a cross-section of elders with mild cognitive impairment (MCI) with and without LLD. Methods Subjects comprised 102 older adults: 27 with ‘pure' amnestic MCI (aMCI), 53 with major depression and cognitive impairment – encompassing 22 late-onset (LOD) and 31 early-onset depression (EOD), and 22 euthymic elders without cognitive impairment (controls). Participants underwent lumbar puncture for determination of CSF concentrations of Aβ1-42, T-tau, and P-tau. Cut-off scores for suspected AD were: Aβ1-42   36.1 pg/mL and Aβ/P-tau ratio  Results ANCOVA (age and schooling as covariates) displayed statistically significant results with respect to CSF biomarkers’ profiles regardless of the socio-demographic divergencies previously identified by one-way ANOVA. Mean Aβ1-42 values (pg/mL) were: aMCI, 360.3 (p  Limitation The main limitation is the relatively small sample. Conclusion Our findings suggest that, distinctively from aMCI, cognitive impairment in LLD is not associated with AD's CSF pathological signature.