Abstracts

While the risk of psychiatric co-morbidity is known to be increased among individuals with epilepsy, the majority of this literature is characterized by retrospective, correlational, and cross-sectional studies. There are no published prospective studies examining the incidence and relative risk of interictal psychiatric disorders in chronic TLE. Beginning in 1998, a large cohort of individuals with temporal lobe epilepsy (TLE) and healthy controls underwent baseline standardized psychiatric interviews. Following a four-year interval, epilepsy patients and controls are returning for re-interview in order to determine the incidence and predictors of interval episodes of Diagnostic and Statistical Manual-IV (DSM-IV) diagnoses in individuals with TLE versus healthy controls. We hypothesize that the four-year incidence and relative risk of Axis I disorders, especially mood disorders, will be significantly elevated among individuals with TLE compared to healthy controls.
Initial selection criteria for individuals with TLE included: 1) age [gt] 17 years, 2) complex partial seizures of temporal lobe origin, 3) no MRI abnormalities other than atrophy, and 4) no other neurological disorder. Initial selection criteria for controls included: 1) age [gt] 17 years, 2) no history of seizures, 3) no neurological disorders, 4) no current substance abuse or learning disabilities, and 5) no history of LOC [gt]5 minutes. At follow-up, standardized psychiatric interviews were conducted using the Structured Clinical Interview for DSM-IV Axis I Disorders-Research Version (SCID-I) to identify both interval and current DSM-IV Axis I disorders. At this writing, 19 individuals with TLE and 13 controls from a total sample of 180 to-be-reassessed patients have participated in SCID-I re-interviews.
The results to date indicate that: 1) [underline]current[/underline] Axis I disorders are more common among individuals with TLE than controls (47% v. 31%); 2) [underline]interval[/underline] (4-year) Axis I disorders occurred more frequently in individuals with TLE than controls (68% v.38%); 3) the most frequent 4-year interval diagnoses were Mood Disorders which were more common in TLE compared to controls (58% v. 23%); 4) the second most common 4-year interval diagnoses were Anxiety Disorders which were more common in controls than TLE subjects (21% v. 31%); and 5) after comparing Axis I diagnoses at baseline to follow-up, only 27.8% of the TLE group and 23.1% of the controls had a new diagnosis identified during the 4 year interval.
The preliminary findings from this 4-year prospective investigation suggest that interval episodes of DSM-IV Axis I disorders occur considerably more frequently among persons with TLE. Mood disorders, major depression in particular, occur more frequently in TLE compared to controls, with no difference in the prospective rates of anxiety disorders.
[Supported by: Epilepsy Foundation Behavioral Sciences Fellowship and M01 RR03186]