B-180: Cognitive Disorder Diagnosis and Intra-Individual Variability in the RBANS in a Veteran Sample

Abstract

Objective: Elevated cognitive dispersion is associated with various pathologies that can affect brain function (Bene et al., 2025), including etiologies that may not result in a cognitive disorder. Since intra-individual variability (IIV) can be observed in normal cognitive performance, developing IIV reference groups is recommended to differentiate normal IIV from pathological IIV (Freilich & Holtzer, 2025). IIV reference groups often exclude psychiatric diagnosis. The current study compares the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) IIV in veterans with no cognitive disorder (NCD), mild cognitive impairment (MCI), and dementia. Method/Data Selection: Veterans with valid performance and the RBANS were included. RBANS-IIV was calculated as the standard deviation of the mean of demographically-corrected RBANS Indices. Assumptions were examined. One-way analysis of variance compared IIV means across diagnostic groups (NCD, n=35; MCI, n=30, dementia, n=12). Results/Data Synthesis: The sample included 77 male veterans who were ethnoracially diverse (White 40.3%, Black 44.2%, Hispanic 14.3%), linguistically diverse (monolingual-English 61%, bilingual-English/Spanish 39%), and older (M_age=66.25, SD=8.99). Within the NCD group, 60% had a psychiatric disorder; primary diagnoses included depression (22.9%), PTSD (17.1%), and anxiety (5.7%). Diagnosis groups had similar levels of education, ethnoracial make-up, and linguistic status. Diagnostic groups had similar RBANS-IIV (F[2,74]= 1.716, p= .187). Conclusions: In an older ethnoracially diverse sample with linguistic diversity, RBANS-IIV was similar between veterans with no cognitive disorder, MCI, and dementia. Notably, the NCD group was largely comprised of veterans with primary psychiatric diagnoses. This negative finding supports the need for IIV reference groups for populations in which psychiatric co-morbidities are prevalent.