Characterizing the Prevalence of Psychiatric Conditions and Fear-Potentiated Startle Response in Civilians with a History of Trauma and Seizures.

Background: Depression, posttraumatic stress disorder (PTSD), and suicidality are more prevalent among people with seizures, but few studies exist in low-resourced minoritized populations. Existing knowledge of the overlapping neurocircuitry between seizure activity in limbic regions (eg, medial temporal lobe epilepsy) and PTSD also suggests that people with seizure histories may exhibit PTSD-like alterations in their fear-potentiated startle (FPS) responses. However, this hypothesis has yet to be systematically tested. Here, we leveraged a large study on stress and trauma to evaluate the prevalence of psychiatric conditions and FPS responses in a low-resourced minoritized population of individuals with a history of seizures. Methods: Prevalence of self-reported PTSD symptoms, depression symptoms, suicidality, and history of suicide attempt were compared between people with and without self-reported seizures among a sample of 3012 predominantly racially marginalized and low-resourced civilians. We compared FPS responses in 13 people with a history of seizures to 13 rigorously matched seizure-free controls. FPS responses were measured using eyeblink data collected during a fear conditioning acoustic startle task. Results: Participants with a history of seizures showed significantly higher prevalence of depression symptoms, suicidality, history of suicide attempt, PTSD symptoms, and probable PTSD diagnosis than seizure-free controls, even after controlling for trauma load. Those with a history of seizures displayed heightened FPS responses and impaired fear discrimination which mimics that of PTSD. Conclusion: These data concur with prior literature on people with a history of seizure activity being at higher risk for psychiatric symptomatology. Additionally, this study provides novel insights on the psychophysiological fear response in trauma-exposed people with a history of seizures, which could inform the identification and treatment of psychiatric vulnerability in these individuals.