B – 52 Examining Loss of Consciousness, Depression, and Cognitive Intra-Individual Variability in Hispanic and White Samples

Abstract Objective This study examined the associations between a history of loss of consciousness (LOC), depression, and cognitive intra-individual variability (IIV). Method Participants included 1041 Hispanic (M = 63.51 years, SD = 7.99; M = 9.72 years education) and 442 White (M = 69.5 years, SD = 8.67; M = 15.54 years education) individuals from the Health and Aging Brain Study - Health Disparities. LOC was assessed via semi-structured interviews, and participants were categorized as reporting or not reporting LOC. Depression was assessed using the Geriatric Depression Scale. Participants underwent cognitive tests (Digit Span, Trail Making Test: Parts A & B, COWAT FAS, Logical Memory I & II, Animal Naming, and Digit Symbol Substitution). IIV was calculated by determining the standard deviation of an individual's overall test battery mean (OTBM) across neuropsychological tests. Results Pearson correlation revealed that the OTBM was negatively correlated with IIV in both Hispanic (r = -.71, p < .001) and White (r = -.54, p < .001) samples. Moderation analysis showed no main effects of LOC or depression on IIV for either group. However, a significant interaction between LOC and depression was found in both Hispanic (b = 74.31, SE = 29.72, t(1037) = 2.50, p = .0126) and White (b = -0.0807, SE = 0.0326, t(438) = -2.48, p = .0135) samples. Conclusion The results of this study revealed that IIV had a stronger association with overall ability in Hispanic individuals. The interaction effect between LOC and depression as it relates to IIV warrants further study.