A-17: The Clinical Utility of Neurofilament Light as a Biomarker for Differentiating Frontotemporal Dementia From Psychiatric Disorders within the Context of Age: A Systematic Literature Review

Abstract Objective: This literature review aims to investigate the diagnostic specificity of neurofilament light (NfL) when diagnosing frontotemporal dementia (FTD) and primary psychiatric disorders (PPD), while accounting for the impact of age on neurofilament light levels. Method/Data Selection: A systematic literature review utilizing “misdiagnosis”, “differential diagnosis”, “frontotemporal dementia”, “psychiatric disorders”, and “neurofilament light chain” as search terms was conducted within APA PsycInfo and PubMed. Peer-reviewed, English-language articles relating to the area of study within the years 2016 to 2026 were read. Results/Data Synthesis: Among the 27 articles meeting the exclusion criteria, NfL was shown to be a general marker for neurodegeneration. This biomarker was successful in differentiating between FTD and PPDs, with accuracy, sensitivity, and specificity. Age and sex were moderators of NfL levels, with age having a significant positive association with NfL levels and males showing significantly higher levels of NfL than females. Conclusions: Given the significant differential ability of NfL as a biomarker for FTD and PPDs, it may be used as a supplemental diagnostic tool alongside DSM criteria when diagnosing FTD. Due to the influence of age and sex on NfL levels, future research is warranted on this relationship to distinguish specific cut-offs for normal aging, sex differences, and neurodegeneration. Implications of the current research emphasize the importance of reducing misdiagnosis of FTD and PPDs by using a combination of approaches to ensure effective interventions.