Neurofilament light chain cannot be measured in urine to distinguish frontotemporal dementia with primary psychiatric diseases

Clinical overlap of the behavioral variant of FTD and primary psychiatric diseases (PPD) hampers diagnostic distinction, leading to frequent misdiagnosis and diagnostic delay. NfL in CSF and blood has shown great potential to accurately distinguish bvFTD from PPD and controls. Measurement of NfL in urine would be a minimal invasive, patient‐friendly biomarker assessment and thereby beneficial for future clinical implementation. We aimed to evaluate the diagnostic value of urine NfL concentration to distinguish bvFTD from PPD and controls and to assess if urine and serum NfL levels correlate.