RESUMO
BACKGROUND: Symptoms of behavioral variant frontotemporal dementia (bvFTD) overlap with primary psychiatric disorders (PPD) making diagnosis challenging. Serum neurofilament light (sNfL) is a candidate biomarker to distinguish bvFTD from PPD, but large-scale studies in PPD are lacking. OBJECTIVE: Determine factors that influence sNfL from a large database of PPD patients, and test its diagnostic accuracy. DESIGN, SETTINGS, SUBJECTS, MEASUREMENTS: Clinical data of people aged 40-81 were obtained from healthy subjects (n = 69), and patients with PPD (n = 848) or bvFTD (n = 82). sNfL was measured using Simoa technology on an HD-X instrument. Data were analyzed using general linear models, and Receiver Operating Characteristic (ROC) curve analyses to determine global and age-specific sNfL cutoffs to distinguish bvFTD from PPD, using the Youden Index. RESULTS: sNfL increased with age, while sex, BMI and diabetes status were modestly associated with sNfL. sNfL was slightly higher in PPD than healthy subjects (14.1 versus 11.7 pg/mL), when controlling for covariates. sNfL was markedly lower in PPD than bvFTD (14.1 versus 44.1 pg/mL). sNfL could differentiate PPD from bvFTD with an AUC = 0.868, but the effect was driven by the younger subjects between age 40-60 years at a cutoff of 16.0 pg/mL. No valid cutoff was detected over age 60, however, values of sNfL above 38.5 pg/mL, or below 13.9 pg/mL, provided 90% diagnostic certainty of bvFTD or PPD, respectively. CONCLUSION: PPD have mildly elevated sNfL compared to healthy subjects but much lower than bvFTD. Results support the use of sNfL as a biomarker to differentiate PPD from bvFTD at age 60 or below, but accuracy decreases in older ages.
RESUMO
(1) Background: This article discusses the first two phases of development and validation of the Three Domains of Judgment Test (3DJT). This computer-based tool, co-constructed with users and capable of being administered remotely, aims to assess the three main domains of judgment (practical, moral, and social) and learn from the psychometric weaknesses of tests currently used in clinical practice. (2) Method: First, we presented the 3DJT to experts in cognition, who evaluated the tool as a whole as well as the content validity, relevance, and acceptability of 72 scenarios. Second, an improved version was administered to 70 subjects without cognitive impairment to select scenarios with the best psychometric properties in order to build a future clinically short version of the test. (3) Results: Fifty-six scenarios were retained following expert evaluation. Results support the idea that the improved version has good internal consistency, and the concurrent validity primer shows that 3DJT is a good measure of judgment. Furthermore, the improved version was found to have a significant number of scenarios with good psychometric properties to prepare a clinical version of the test. (4) Conclusion: The 3DJT is an interesting alternative tool for assessing judgment. However, more studies are needed for its implementation in a clinical context.
