Abstracts

Rationale: Bipolar disorder is characterized by cyclical changes in mood and behavior. A previous community-based study using the Mood Disorders Questionnaire (MDQ) to identify the prevalence of bipolar symptoms suggested that bipolar symptoms occur in as many as 12.2% of community-based epilepsy patients, and are frequently unrecognized (Ettinger AB, et al. Neurology 2005; 65(4): 535-540). A question remains whether this indicates bipolar disorder or an alternative mood instability syndrome. In this study, we assess the rate of bipolar symptoms as measured by: 1) the MDQ in a tertiary epilepsy center setting, 2) the meaning of a positive MDQ score in epilepsy patients, 3) the utility of alternative screening tools for mood instability in epilepsy patients, 4) the correlation of mood instability with seizure-related variables, and 5) the relation of a positive MDQ score with quality of life.Methods: This ongoing prospective observational study recruited adult epilepsy subjects at the Comprehensive Epilepsy Center at the Long Island Jewish Medical Center. Patients with mental retardation or non-epileptic seizures were excluded from this study. In phase 1, subjects completed a set of self-reporting questionnaires including the MDQ, the Bipolar Spectrum Diagnostic Scale (BSDS), the Sheehan Disability Scale (SDS), and the Quality of Life in Eplepsy-89 Patient Inventory (QOLIE-89). Subjects who met the MDQ positive criteria were eligible for Phase 2 of the study, which included two additional self-reporting mood questionnaires, collection of information on demographic, seizure, and medications, and a structured psychiatric interview (SCID-I modules A and D, MINI section L) to clarify whether a positive MDQ score indicated an actual diagnosis.Results: To date, of the 35 subjects who enrolled and completed Phase 1 of the study, 5 (14.3 %) met MDQ positive criteria, similar to the 12.2 % found in the previous community-based study. Three of these five subjects completed Phase 2 of the study. Results from the structured psychiatric interviews indicated that none of these subjects met the DSM-IV diagnosis of bipolar disorder. Two did not have any mood disorder, and one had atypical psychosis. Results from the BSDS showed that 11 out of 35 subjects were at or above the optimum threshold for positive diagnosis. Interestingly, all five subjects who met MDQ positive criteria also had the five highest BSDS scores. As additional subjects meet MDQ criteria, further analyses assessing the relationship of bipolar symptoms with quality of life and other seizure related variables will be presented.Conclusions: The prevalence of bipolar symptoms in a tertiary epilepsy center is similar to rates found in a community-based sample of adults in the United States. To date, our data suggests bipolar symptoms are not equated with DSM-IV-defined bipolar disorder. We speculate that mood instability may relate to the mood instability seen in interictal dysphoric disorder. (Supported by GlaxoSmithKline)