In a sample of 77 dyads, involving depressed patients at least 50 years of age and their family or friends (informants), patient illness burden and cognitive decline were associated with self-informant rating discrepancies for facets of Revised NEO Personality Inventory (NEO-PI-R) Openness and Extraversion. Informant judgments about Neuroticism and Conscientiousness were not associated with illness burden or cognitive function, underscoring the potential utility of risk-detection strategies that rely on informant-report in these two domains. Findings suggest the need for research on how patient illness severity and cognitive function affect how friends and family use or misuse information when making judgments about older depressed patients.