A - 114 Exploring Alzheimer’s Disease: the Interplay of Depression, Substance Use, and Neurocognition

Abstract Objective Depression and substance use (SU) can significantly impact one’s neurocognition and are potential risk factors for Alzheimer’s Disease (ad). The project aimed to explore whether a history of depression and/or SU could predict baseline performance on neuropsychological assessment among individuals with and without ad. Method Data from the National Alzheimer’s Coordinating Center (NACC) was analyzed. N = 9114 participants (41.5% Male, 58.5% Female; 56.7% Normal Cognition, 43.2% ad) at their first visit were selected. A series of linear regression models, separated by presence of ad diagnosis, were run to determine if a history of depression, and/or SU, age, race, sex, education level, and APOE status would predict performance on selected neuropsychological assessments measuring facets of executive functioning (EF) (Trail Making, Digit Span, and Wechsler Adult Intelligence Scale (WAIS)). Results Depression was a significant predictor of performance on the WAIS in the normal cognition (β = −0.12,p 0.001) and ad (β = −0.14,p 0.001) groups, on Number of Correct Digit Span Backward Trials in the normal cognition (β = 0.09,p 0.01) and ad (β = −0.10,p 0.01) groups, and on Number of Correct Digit Span Forward Trials in the ad group (β = −0.11,p 0.001). SU was a significant predictor of performance on Number of Correct Digit Span Backward Trials in the ad group (β = 0.20,p 0.01). Demographic variables were also significant. Conclusions Depression predicted performance on multiple neuropsychological assessments across diagnostic groups compared to SU. EF facets measured across assessments may have been further impacted by ad and mental health history compared to those with normal cognition endorsing mental health history.