MAPT and early-onset autosomal dominant Alzheimer disease: Alzheimer’s disease (AD) is a complex and multifactorialneurodegenerative disease, which is currently diagnosed via clinicalsymptoms and nonspecific biomarkers (such as Aβ1–42, t-Tau, and p-Tau) measured in cerebrospinal fluid (CSF), whichalone do not provide sufficient insights into disease progression.In this pilot study, these biomarkers were complemented with small-moleculeanalysis using non-target high-resolution mass spectrometry coupledwith liquid chromatography (LC) on the CSF of three groups: AD, mildcognitive impairment (MCI) due to AD, and a non-demented (ND) controlgroup.