Neuropsychiatric Symptoms of Epilepsy

2 Depression
33
ral lobectomy. For example, in a study of 100 consecutive patients, only 12 % of
patients who reached complete seizure freedom after surgery (mean follow-up period
8.3 ± 3.3 years) had a lifetime history of depression, while such history was identified
in 67 % of patients who had auras, but no complex partial and/or secondarily generalized
tonic-clonic seizures, and in 79 % of patients with persistent disabling seizures
[ 63 ]. These data were confirmed in two other studies that included patients with mesial
temporal sclerosis (MTS): in one study of 280 patients, those with a preoperative psychiatric
diagnosis (38 % of the entire cohort) were significantly less likely to remain
seizure-free [ 64 ], while in the second study of 115 patients, a presurgical history of
major depressive disorders was a risk factor for persistent postsurgical seizures [ 65 ].
Impact on the Quality of Life
Several studies of patients with treatment-resistant epilepsy demonstrated that
depressive disorders are strong predictors of poor quality of life, even after controlling
for seizure frequency, severity, and other psychosocial variables [ 35 , 66 – 69 ]. In
one of these studies, depression was significantly associated with poor quality of
life, independently of seizure type, but seizure freedom for the last 3 months
improved the quality-of-life ratings [ 66 ]. Of note, comorbid depressive and anxiety
disorders have a worse impact on the quality of life of PWE than the depressive or
anxiety disorders occurring alone, and particularly when a major depressive episode
is comorbid with more than one anxiety disorder [ 35 ].
Impact on Health-Care Costs
Patients with untreated depression were found to use significantly more health
resources of all types, independent of seizure type or duration [ 70 ]. Mild-tomoderate
depression was associated with a twofold increase in medical visits compared
with nondepressed controls, while severe depression was associated with a
fourfold increase. This could be in part due to the above reported increased risk of
poor tolerance of AEDs and worse response to pharmacological and surgical treatments.
The presence and severity of depression was also a predictor of lower disability
scores, irrespective of the duration of the seizure disorder.
Identification of Depressive and Anxiety Disorders
in the Outpatient Clinic
Providing clinicians with user-friendly self-reported screening instruments of
depressive and anxiety disorders is probably the best solution to facilitate their identification
in PWE in a busy outpatient clinic. Several self-reported instruments have
been developed to identify and quantify the severity of symptoms of depression and