Abstracts

Rationale: Psychiatric comorbidities are relatively frequent in people with epilepsy (PWE). Their relation with the seizure disorder is complex and multifactorial. Most available data have been based on cross-sectional studies in patients with chronic epilepsy, though others have considered time order of these associations. We investigated whether the frequency and type of seizures preceding the diagnosis of focal epilepsy were associated with symptoms of depression, anxiety and suicidality identified at the time of diagnosis of focal epilepsy. Methods: Data from participants with newly diagnosed focal epilepsy enrolled in the Human Epilepsy Project (HEP) were used to address these questions. These included: (i) seizure type and frequency of seizures, preceding the diagnosis of epilepsy; (ii) symptoms of depression, anxiety and suicidality obtained at the time of diagnosis with three self-rating instruments. Psychiatric disorder screens included the generalized anxiety disorder-7 (GAD-7), the Neurologic Disorders Depression Inventory in Epilepsy (NDDI-E), and the Centers for Epidemiologic Studies Depression Scale (CESD). In addition, current and past suicidal ideation and behavior was assess with the Columbia Suicide Severity Rating Scale (CSSRS). Data were analyzed with SAS. Due to the distribution of seizure frequency up to the diagnosis of epilepsy, Wilcoxin rank sum tests were used to analyze associations between number of seizures prior to epilepsy and categorical severity on the screens for psychiatric disorders. Results: Levels of generalized anxiety, suicidal behavior, symptoms of depression and of major depression were not associated with any focal seizure frequency prior to the epilepsy diagnosis. Results differed when separate focal seizure types were considered. Prior seizure frequency was associated with: any suicidal ideation in the past 6 months (p=04) and the absence of symptoms of major depressive episodes (0=0.02) for secondary generalized seizures (N=93); and any suicidal thought or behaviors (p=0.01) and anxiety (p=0.03) in focal seizures with impairment of consciousness or responsiveness (N=61; p=0.01). There were no significant associations between seizure frequency before epilepsy diagnosis and psychiatric screens in focal seizures with observable motor or autonomic symptoms (N=13) or in focal seizures involving subjective sensory or psychic phenomena only (N=33). Conclusions: Seizure frequency before epilepsy diagnosis was associated with symptoms of depression and anxiety, and suicidal thoughts or behaviors in secondarily generalized tonic-clonic seizures and in focal seizures with impairment of consciousness or responsiveness. There were no associations with other focal seizure types, perhaps suggesting lower power to detect a difference, particularly using non-parametric tests. It is not possible to determine time order of these associations as participants may have had a long history of psychiatric disorders prior to the diagnosis of epilepsy. These data highlight the importance of screening for psychiatric comorbidities at the time of the initial diagnostic evaluation. Funding: The Epilepsy Study Consortium (ESCI) is a non-profit organization dedicated to accelerating the development of new therapies in epilepsy to improve patient care. The funding provided to ESCI to support HEP comes from industry, philanthropy and foundations (UCB Pharma, Eisai, Pfizer, Lundbeck, Sunovian, The Andrews Foundation, The Vogelstein Foundation, Finding A Cure for Epilepsy and Seizures, Friends of Faces and others).