The objective of this study is to apply AclarusDx™ signature in a reference US Center in 160 patients newly referred to one of the three study centers within the Cleveland Clinic, Center for Brain Health network, for diagnostic workup. Only AclarusDx™ will be added to the panel of tests usually performed at the centers to establish diagnosis. AclarusDx™ will be used for investigational use only, not for diagnostic purpose. The ultimate goal is to define the clinical utility of AclarusDx™ to provide Primary Care Physicians (PCPs) with a tool that will help them in making the diagnosis of Alzheimer's Disease (AD).