Depression but not seizure frequency predicts quality of life in treatment-resistant epilepsy

Background: The two-thirds of patients with epilepsy who become seizure-free have a quality of life (QOL) similar to the general population. The major treatment challenge is patients with refractory epilepsy. Whereas neurologists typically focus on seizure reduction in the treatment of these patients, results of studies relating seizure frequency to QOL are conflicting. As depression is associated with reduced QOL in epilepsy and antiepileptic medications (AEDs) can cause depression, it is important to determine the relative roles of depression and seizure frequency in QOL in refractory epilepsy. Methods: Prospective evaluation was conducted of patients with refractory epilepsy being admitted to an inpatient video-EEG monitoring unit. The impact of clinical variables (age, sex, marital status, seizure frequency, duration and type of seizure disorder, seizure localization, number of AEDs, depression) on QOL was analyzed. Results: Depression was a powerful predictor of QOL (n = 122, β = -35.8, p < 0.0001). No other variable predicted QOL. Depression was common (54%), severe (19% with suicidal thoughts), underdiagnosed (37%), and largely untreated (17% on antidepressants). Conclusions: Treatment of depression may be inadequately prioritized in the management of intractable epilepsy.