The present invention provides methods for diagnosing a neurological disease in a subject, screening for or assessing the risk of developing a neurological disease in a subject, monitoring progression of a neurological disease in a subject, assessing efficacy of a therapy for a neurological disease in a subject, and identifying a subject suffering from a neurological disease that may be successfully treated by an agent that affects levels of a biomarker such as a tau protein or an amyloid beta. The methods generally feature (a) obtaining a cerebrospinal fluid (CSF) sample from a subject; (b) providing a cerebrospinal fluid (CSF) correction factor for CSF obtained from a subject for at least one biomarker; and (c) determining whether the biomarker is present in elevated amounts or concentrations in the cerebrospinal fluid (CSF) sample. The neurological disease may be, for instance, impaired cognition or dementia such as Alzheimer's Disease (AD) or Mild Cognitive Impairment (MCI). The biomarker may be a tau protein such as P-tau231 or an amyloid beta (Aβ) such as Aβ42 or Aβ40.
METHODS FOR DIAGNOSING AND ASSESSING NEUROLOGICAL DISEASES