Abstracts

Rationale: In patients with epilepsy, psychiatric symptoms are known to occur during the postictal period. Furthermore, interictal psychiatric symptoms can worsen in severity during the postictal period, but the actual frequency with which this occurs is unknown. The purpose of this study is to evaluate the frequency with which interictal symptoms of anxiety, irritability and depression worsen during the postictal period in a large cohort of outpatients with epilepsy.Methods: A self-rating screening instrument of 46 items testing the presence of symptoms of anxiety , depression and irritability was given to 188 outpatients with epilepsy on two separate occasions 2 weeks apart of each other. Each item was scored on a 4 point Likert scale (1 = absent; 4: = all the time) and assessed the presence of the symptom for the two previous weeks. We only considered symptoms with a score of 3 or 4 (e.g., occurring most of the time). Postical exacerbation in severity of interictal symptoms (PESIS) was investigated for each item. The presence of an interictal mood and anxiety disorder, according to the DSM-IV classification was established with the MINI International Neuropsychiatric Inventory and included: no DSM-IV diagnosis ( n = 103), Subsyndromic Depressive Episode (SSDE, n = 26), Major Depressive Episode (MDE, n = 10), Anxiety Disorder (AD, n = 28) and Mixed AD + MDE ( n = 21). Results: The occurrence of PESIS was found to be relatively frequent as a mean ( SD) of 27% (11.5) of patients endorsed at least one PESIS. The mean ( SD) number of PESIS/patient was 14.7 11.5 (range: 0-44). There was no difference in the frequency of PESIS among patients with SSDE (21.0 8.1), MDE (23.7 9.7), AD (20.2 10.6). As expected patients with mixed MDE+AD had a significantly greater number of PESIS (32.3 7.5, p<0.0001 (ANOVA with post-Hoc Bonferroni]), Conclusions: PESIS are relatively frequent in patients with mood and anxiety disorder who suffer from epilepsy and should be distinguished from pure postictal psychiatric symptoms.