The purpose of this Program Announcement (PAR) is to enable clinical validation of strong candidate biomarkers for neurological diseases and conditions. Specifically, the goal of this PAR is to enable the rigorous validation of biomarker measurements within the clinical population of interest to establish the positive and negative predictive values of the candidate biomarker consistent with FDA guidelines. This PAR assumes that 1) a candidate biomarker has already been identified, 2) detection method technology ha...