Association Between Psychiatric Comorbidities and Mortality in Epilepsy

ABSTRACT Objective: To explore the impact of psychiatric comorbidities on all-cause mortality in adults with epilepsy from a cohort of patients admitted for video-electroencephalogram monitoring (VEM) over two decades. Methods: A retrospective medical records audit was conducted on 2709 adults admitted for VEM and diagnosed with epilepsy at three Victorian comprehensive epilepsy programs from 1995-2015. 1805 patients were identified in whom the record of a clinical evaluation by a neuropsychiatrist was available, excluding 27 patients who died from a malignant brain tumour known at the time of VEM admission. Epilepsy and lifetime psychiatric diagnoses were determined from consensus opinion of epileptologists and neuropsychiatrists involved in the care of each patient. Mortality and cause of death were determined by linkage to the Australian National Death Index and National Coronial Information System. Results: Compared to the general population, mortality was higher in people with epilepsy (PWE) with a psychiatric illness (standardised mortality ratio [SMR] 3.6) and without a psychiatric illness (SMR 2.5). PWE with a psychiatric illness had greater mortality compared to PWE without (hazards ratio 1.41, 95% confidence interval 1.02-1.97) after adjusting for age and sex. No single psychiatric disorder by itself conferred increased mortality in PWE. The distribution of causes of death remained similar between PWE with psychiatric comorbidities and those without. Conclusion: The presence of comorbid psychiatric disorders in adults with epilepsy is associated with increased mortality, highlighting the importance of identifying and treating psychiatric comorbidities in these patients.