Abstracts

Various authors have questioned the sensitivity of the diagnostic criteria suggested by the Diagnostic and Statistical Manual of Mental Disorders (Third and Fourth editions) to identify certain types of depressive disorders in epilepsy. The purpose of this study was to determine whether patients with epilepsy and [italic]no identifiable current mood disorder[/italic] by DSM-IV criteria present symptoms of depression, irritability and anxiety and if so, to establish whether their presence has a direct impact on these patients[apos] quality of life ratings.
We created a 46-item mood disorder instrument ([italic]Neurologic Disorders Depression Inventory-Epilepsy[/italic]) with the aim of identifying symptoms of depression, anxiety, irritability, psychosis and physical symptoms. Each item was scored on a 1-4 Likert Scale. 205 adult outpatients were prospectively evaluated at five university-based epilepsy centers. All patients completed the NDDI-E, a comprehensive set of mood and medication toxicty instruments and the Quality of Life in Epilepsy Inventory-89 (QOLIE-89). A current mood disorder was identified with the structured Clinical Interview for DSM-IV Axis I Disorders (SCID). NDDI-E items were grouped into five domains: mood, irritability, anxiety, psychosis and physical symptoms. Forty-three patients met DSM-IV criteria for one of the [italic]current[/italic] mood disorder categories and were excluded from the study; 162 patients were included. Patients with [italic]at least one positive item[/italic] (scored as 3 or 4) in the[italic] three[/italic] domains of mood, anxiety and irritability were coded as [quot]symptomatic[quot] and the rest [quot]not symptomatic[quot].We compared the QOLIE-89 scores between symptomatic and non-symptomatic patients and investigated whether the [quot]item load[quot] (number of items per domain) had a significant impact on the QOLIE-89 scores.
There were 71 symptomatic (44%) and 91 non-symptomatic patients (56%). Symptomatic patients experienced a median of 7 mood items, 4 anxiety items, 6 irritability items and 3 psychosis items. The QOLIE-89 scores of the symptomatic patients were significantly lower (68.5[plusmn]13.3) than those of non-symptomatic (76[plusmn]14.7, p = 0.0002, Wilkoxon Rank-Sum). Among the 71 symptomatic patients, bigger item loads were significantly associated with worse QOLIE-89 scores for all three domains: mood (1 - 4 vs. 5 - 16 items, 73.7[plusmn]12.2 vs. 64.7[plusmn]12.8, p = 0.004), anxiety (1 - 3 vs. 4 - 8 items; 74.1[plusmn]11.0 vs. 62.1[plusmn]12.8, p = 0.0002) and irritability (1 - 3 vs. 4 to 13 items; 75.1[plusmn]11.7 vs.65.6[plusmn]13.0, p = 0.0037).
These data show that in epilepsy patients, the available DSM-IV criteria of mood disorders are insensitive in identifying relatively frequent symptoms of depression that have a negative impact in quality of life. We are investigating whether these symptom clusters lead to homogeneous clinical pictures, as suggested by Kraepelin (1923) and Blumer (1995).
[Supported by: Glaxo-Smith-Kline]