Abstracts

Rationale: While considerable attention has been paid to the finding that depression is related to self-reported cognitive complaints in patients with epilepsy, less is known about the variables that mediate cognitive complaints in epilepsy patients without depression. This study explored several possible determinants of self-reported cognitive complaints in patients with epilepsy who do not meet criteria for a mood disorder. Specifically, it was hypothesized that subclinical depressive symptoms, active seizures, anti-epileptic medication polypharmacy, other medical conditions, unemployment and low education would be associated with greater self-reported cognitive complaints. Methods: The sample consisted of 141 patients with a clinical diagnosis of epilepsy and receiving outpatient epilepsy care at the UW Regional Epilepsy Center. The current sample was selected from a larger sample of patients screened for inclusion in a clinical trial. The current study participants consisted of those patients who screened negative for major depression, dysthymia and minor depression, and who returned a mail survey. The survey assessed demographic information (employment status and education), medical variables (seizure within last month, anti-epileptic medications, other medical conditions), symptoms of depression, and history of depressive episodes. Thirty-five percent of the sample reported at least one symptom of depression, while 47% of the sample reported a prior depressive episode. Cognitive complaints were assessed with selected items from the cognitive subscale of the Quality of Life in Epilepsy. Results: Due to skewed data, nonparametric statistics (Mann-Whitney U Test) were used for all analyses. As predicted, those patients with subclinical symptoms of depression (e.g., poor sleep, poor appetite, and low energy) or a history of depressive episodes reported more cognitive problems than those without these symptoms [sleep, p<.001; appetite, p<.01; energy, p<.01; prior depressive episodes, p<.01]. However, contrary to expectations, other medical and demographic variables did not impact reported cognitive complaints [polypharmacy, active seizures, other medical conditions, education, employment status, all p>.05]. The frequency of sleep, energy and appetite problems was not impacted by use of any specific anti-epileptic medication. Conclusions: In epilepsy patients who do not meet clinical criteria for a clinical mood disorder, cognitive complaints are associated with a history of depression, as well as current subclinical depressive symptoms. In contrast, patients with medical or demographic variables known to impact objective cognitive functioning did not report more cognitive complaints. Thus, even in patients who are not clinically depressed, cognitive complaints appear to be determined primarily by depressive symptoms rather than due to actual cognitive problems. Future research is needed to determine whether treatment for depressive symptoms results in a reduction of cognitive complaints.