Effects of seizure frequency, depression and generalized anxiety on suicidal tendency in people with epilepsy

Purpose: The highest risk of suicide was identified among patients diagnosed with both epilepsy and comorbid psychiatric disease. The most common comorbid psychiatric conditions of epilepsy are anxiety and depression. This study examines whether and how seizure frequency, depression and generalized anxiety interact to influence suicidal tendency. Methods: A consecutive cohort of PWE was recruited from the First Affiliated Hospital of Chongqing Medical University. Each patient completed the Neurological Disorders Depression Inventory for Epilepsy scale[NDDI-E), the Generalized Anxiety Disorder-7 (GAD-7), and the suicidality module of Mini-International Neuropsychiatric Interview(MINI) v.5.0.0. Spearman's correlation and moderated mediation analysis were used to examine the associations among seizure frequency, depression, generalized anxiety and suicidal tendency. Results: Seizure frequency was positively associated with suicidal tendency. Depression severity partially mediated the relationship between seizure frequency and suicidal tendency. The indirect effect of seizure frequency on suicidal tendency was positive, and accounted for 50.2 % of the total effect of seizure frequency on suicidal tendency. The indirect effect of seizure frequency on suicidal tendency through depression severity was positively moderated by generalized anxiety severity. Conclusions: Reducing seizure frequency may be the basis of suicide prevention in PWE. At the same time, the effect of seizure frequency on suicidal tendency can be partially explained by the mediation of depression severity, and the magnitude of the indirect effect of seizure frequency on suicidal tendency was contingent upon generalized anxiety severity. In addition to depression severity, generalized anxiety severity also exerts an important effect on suicidal tendency in PWE.