Abstracts

Rationale: Memory difficulties are amongst the most common complaints in patients with epilepsy. While many variables have been shown to affect patient report of memory difficulties, mood has consistently emerged as a leading factor. That is, depression has been shown to magnify the discrepancy between reported and actual memory impairments. However, the degree to which patients with depression may in fact be more impaired than their non depressed counterparts is less clear, as depression has also been found to suppress objective performance on tasks of memory. Thus, the aim of the current study was to contribute to the current body of literature by delineating the nature of the relationships between mood, subjective memory complaints, and objective memory performance in patients with epilepsy. Methods: Forty three patients with medically refractory epilepsy who were being considered for resective surgery completed presurgical evaluations that included results from video-EEG monitoring, MRI, and neuropsychological evaluation. Localization data were provided by the patients' neurosurgeon and epileptologists. The final sample included 20 patients with a left-sided seizure focus, 17 patients with a right-sided seizure focus, and 7 patients with bilateral involvement. The Beck Depression Inventory-II (BDI-II), Memory Complaints (MCI), Quality of Life in Epilepsy (QUOLIE-31), and Rey Auditory Verbal Learning Test (RAVLT) were administered as part of the comprehensive neuropsychological battery. Results: Patients who obtained a score of ≥19 on the BDI-II (considered "moderate" depression) reported significantly more difficulties with memory on the MCI [M=28.17, SD=8.57] than patients who obtained a score of <19 on the BDI-II [M=16.00, SD=10.48, t(20)=2.53, p=.020]. The patients with high depressive symptomatology also reported significantly more difficulties with memory problems impacting their quality of life [M=43.13, SD=10.32] than those with low depressive symptomatology [M=52.21, SD=8.86, t(30)=-2.41, p=.022). Memory performances based on total number of words learned on a list-learning task as well as the number of words retained after a delay did not differ significantly between groups. There were no significant group differences in total IQ or laterality of seizure focus. Conclusions: The current results were consistent with previous research indicating that mood is associated with greater subjective memory difficulties. Our findings indicate that although patients with depressive symptoms are more likely to report memory problems, their performance on objective memory tasks does not significantly differ from that of patients without significant depressive symptoms. These findings call into question the extent to which mood impacts objective performance on memory tasks in depressed patients with epilepsy and thus have important implications for interpretation of neuropsychological findings in this population.