Effect of drug treatment changes and seizure outcomes on depression and suicidality in adults with drug-resistant focal epilepsy

OBJECTIVE: To investigate changes in depressive and suicidality status and their relationship with seizure outcomes after the addition or substitution of another antiseizure medication (ASM) in adults with drug-resistant focal epilepsy. METHODS: Seven hundred seventy consecutively enrolled patients were assessed and followed prospectively for seizure outcome and depressive status over a 6-month period after starting treatment with a newly introduced ASM. The Neurological Disorders Depression Inventory for Epilepsy (NDDIE) was used to screen for depression and suicidality. Correlations of NDDIE results with clinical and treatment-related variables were assessed by using a stepwise logistic regression model. RESULTS: At baseline, 50% of patients had a positive screening test result for depression and 13% had a positive screening test result for suicidal ideation. A psychiatric comorbidity at baseline was associated with a 2.3 times increased risk of an initially negative NDDIE screening result becoming positive at re-assessment after 6 months. In addition, the number of ASMs taken at baseline correlated with an increased risk of a change in depression screening test results from negative to positive during follow-up, whereas no association was identified with sociodemographic and epilepsy-related variables, including seizure outcomes. Approximately 6% of patients who were initially negative at screening for suicidal ideation became positive at the 6-month re-assessment. The risk of switch from a negative to a positive screening test result for suicidal ideation was increased more than two-fold in individuals who screened positive for depression at baseline, and was unrelated to the type of ASM introduced, sociodemographic variables, or seizure outcomes. SIGNIFICANCE: Almost 1 in 5 adults with drug-resistant focal epilepsy who screen negative for depression become positive when re-assessed 6 months after a treatment change. At re-assessment 6 months later, 6.1% who scr