Epilepsy is the third most common neurological disorder among older adults, and as adults are living longer, the incidence of epilepsy is increasing (Kun Lee, 2019). The purpose of this study is to examine 1. differences in quality of life (QOL) between older and younger adults with medically intractable epilepsy and 2. the impact of seizure frequency, seizure duration, depression, sex, and marital status on QOL. Given differences in the prevalence rates of depression between men and women and importance of depression in QOL, we predicted that sex and marital status would moderate the effect of depression on total QOL (TQOL).

Hypothesis I: Compared to younger adults, older adults with epilepsy will report lower TQOL scores and lower scores on subscales measuring energy/fatigue, cognition, and medication effects. Hypothesis II: Seizure variables and depression will significantly account for TQOL scores in both groups (younger and older) above demographic variables (sex, marital status, and education). Hypothesis III: Sex will moderate the effect of depression in both groups and marital status will moderate the effect of depression only in the older adults.

Participants were 607 adults (> 18 years old) who were prospective candidates for epilepsy surgery and underwent a comprehensive neuropsychological evaluation including QOL assessment using the Quality of Life in Epilepsy Scale-31 (QOLIE-31). Individuals were grouped by older (> 50 years old; N = 122) and younger adults (< 50 years old; N = 485). Hierarchical regression was used to examine the proposed associations.

Hypothesis I: In contrast to our hypothesis, a one-way ANOVA did not reveal significant differences between the older and younger groups on the QOL subscales, TQOL, or depression.

Hypothesis II: For older adults, longer seizure duration was associated with better TQOL; bivariate correlations showed no evidence of statistical suppression. Higher depression scores were associated with worse TQOL. Overall, the model accounted for 39.6% of variance among older adults. For younger adults, only depression was a significant predictor of TQOL wherein higher depression scores were associated with worse TQOL. Overall, the model accounted for 36.1% of the variance among younger adults. Hypothesis III: There was no moderation between depression and marital status in older or younger adults (b = -.009, p > .05). There was multicollinearity evidenced by VIF (variance inflation factor) greater than 10, so the associations between depression and sex could not be examined.

Overall, there were no significant differences between QOL in younger versus older adults. Greater depression symptoms were associated with lower TQOL in both groups. Longer seizure duration was a significant predictor of better TQOL in older adults only, perhaps indicating better adjustment to having a seizure disorder with longer duration of epilepsy. Lastly, marital status did not moderate the effects of depression on TQOL and the moderating effects of sex on TQOL could not be assessed due to multicollinearity. Study limitations include dichotomizing the sample into these particular age groups and the heterogeneity of seizure types.