B-84: Neurocognitive Functioning in Presurgical Persons With Epilepsy With and Without Current Cannabis Use

Abstract

Objective: Cannabis use (CU) is increasingly common among persons with epilepsy (PWE), yet its neurocognitive impact remains unclear. Prior work suggests associations with verbal learning and memory; however, findings are mixed and comprehensive neuropsychological evaluations in clinical epilepsy samples with CU are limited. This study examined neurocognitive functioning in cannabis-using and non-using adults with epilepsy. Method/Data Selection: PWE (N = 78; Mage = 39.73, SD = 14.50) undergoing neuropsychological evaluation for epilepsy surgical planning were classified by current CU (past-month; n = 32) or no past-month CU (n = 46). Cognitive domains included premorbid intellectual functioning (Test of Premorbid Functioning), verbal (CVLT) and visual learning/memory (BVMT-R), attention/working memory (WAIS-IV Digit Span), processing speed (WAIS-IV Coding), executive functioning (TMT-B), and language (Boston Naming Test). Group differences were evaluated using one-way ANOVA with false discovery rate (FDR) correction. Results/Data Synthesis: CU and non-CU groups demonstrated comparable performance across cognitive domains. Groups did not differ in age or premorbid functioning, but sex differed, with more males in the CU group. A trend-level difference was observed for delayed verbal recall, with CU groups performing lower than non-users (CVLT long-delay free recall: F = 3.48, p = .066, η2 = .047), however, this did not persist after correction or ANCOVA controlling for sex. Conclusions: In this clinical epilepsy sample, current CU was not associated with differences in neurocognitive functioning. Effects were small, suggesting subtle cognitive differences. CU was defined dichotomously (past-month use) and did not capture recency, frequency, or quantity. Future longitudinal studies with larger samples are needed to clarify neurocognitive effects of cannabis among PWE.