Abstracts

Rationale: Symptoms of depression and anxiety have been associated with a negative impact on health related quality of life measures (HRQOL) of patients with epilepsy (PWE), including a perception of worse adverse events to antiepileptic drugs (AED). Whether a major depressive episode (MDE) with or without a comorbid anxiety disorder (AD) or whether a subsyndromic type of depression impact differently these variables is yet to be established. The purpose of this study is to answer these two questions.Methods: 193 consecutive outpatients (130 women, mean age 39±11.7 years) were recruited from five epilepsy centers. The mood module of the Structured Clinical Interview for DSM-IV (SCID-I) was used to identify current and past mood disorders. Other current Axis I DSM-IV diagnoses were identified with the MINI International Neuropsychiatric Interview (MINI). Health-related quality of life was measured with the Quality of Life in Epilepsy -89 (QOLIE-89). Patients also completed the Beck Depression Inventory-II (BDI-II). The severity of adverse events to AEDs was identified with the self-rating scale Adverse Event Profile (AEP). Subsyndromic depression (SSD) was defined as the presence of BDI-II total scores >12 in the absence of any current MDE identified with the MINI or SCID. Finally, seizure frequency was coded as seizure-freedom for at least the last six months (yes/no). Diagnostic groups: (1) no current psychiatric symptoms. (2) Current SSD. (3) Current MDE only. (4) Current AD(s) only. (5) Current mixed MDE+AD. (6) Dysthymia. Statistical analyses: QOLIE and AEP scores were compared among the six groups. Logistic regression models were developed to identify the predictors of poor HRQOL and toxicity to AEDs (high AEP scores). Results: Among the 193 patients, 103 (53.4%) were asymptomatic, 22 (11.4%) had SSD, 10 (5.2%)MDE, 30 (15.5%) AD, 24 (12.4%) MDE+AD and 4 (2.1%) dysthymia. This latter group was eliminated from further analyses. As shown in the table, there was a significant difference in QOLIE-89 (F = 49.1, p<0.0001) and AEP (F = 36.4, p<0.0001) scores among the six groups. Significant differences for QOLIE-89 scores were accounted by differences between: No symptoms vs all groups (p<0.0001), SSD vs MDE+AD (p<0.0001) and AD vs AD+MDE (p<0.0001). For AEP scores, significant differences between the same groups were identified (p<0.0001, p = 0.006 and p = 0.001, respectively). Logistic regression models identified psychiatric disorders (P<0.0001), high AEP score (P<0.0001) and persistent seizures (p = 0.002) as predictors of poor QOLIE. Psychiatric disorders (p<0.0001) and persistent seizures (p = 0.003) were independent predictors of worse adverse events. Conclusions: These findings demonstrate a differential negative association between SSD, MDE and AD on HRQOL and on adverse events to AEDs, with comorbid MDE+AD yielding the worse association. The data also suggest the need to define carefully the type of psychiatric disorders in drug studies and in HRQOL research.