Psychiatric Comorbidities Tied to Higher Mortality in Epilepsy

Mortality is higher in adults with epilepsy who have comorbid psychiatric illness compared with the general population, according to study results published in Neurology: Clinical Practice.

Preliminary studies have indicated that patients with epilepsy and psychiatric disorders may have greater risk of mortality. Other research has shown increased neuropsychiatric symptoms are linked with increased resistance to antiepileptic medication. The objective of the current study was to evaluate mortality in patients who have co-occurring epilepsy and psychiatric disorders.

The researchers retrospectively reviewed the admission records of patients with uncontrolled seizure disorder or difficult to control epilepsy who underwent video-electroencephalography (VEM) at 3 hospitals in Melbourne, Australia from 1995 to 2015. Each underwent 1 to 3 weeks of continuous VEM and neuroimaging with 1.5T/3.0T magnetic resonance imaging (MRI). Patients were assessed for psychiatric and epilepsy diagnoses. The researchers included adult patients (n=1805) who received a formal epilepsy diagnosis in the study.

In the study, the mortality of patients with epilepsy exceeded the mortality of the general population, regardless of co-occurrence of lifetime history of psychiatric disorder (comorbid psychiatric disorder SMR 3.6 95% CI 2.9-4.4, no psychiatric disorder SMR 2.5 95% CI 1.9-3.2).

After adjustment for age and sex confounders, mortality was higher in patients with epilepsy who had comorbid psychiatric disorders (52% of the cohort) compared with patients who solely had epilepsy (HR 1.41 95% CI 1.02-1.97).

In an analysis of patients with known epilepsy type and syndrome, the researchers found, after they adjusted for epilepsy type and lesionality, that mortality was higher in people with epilepsy who had comorbid psychiatric disorders compared with those who did not (HR 1.54 95% CI 1.05-2.24).

Patients who had 1 comorbid psychiatric disorder did not have higher risk of mortality compared with patients without psychiatric comorbidities. No specific comorbid psychiatric disorder carried significantly different mortality compared with patients without psychiatric comorbidities.

Diseases of the nervous system, neoplasms, and external causes of mortality were the most common causes of death among the 147 patients in the cohort (87 with lifetime history of psychiatric disorder) who died during follow-up. Thirty-six patients were definite (n=29) or probable (n=7) sudden unexplained death in epilepsy (SUDEP) suspects, the researchers reported.

There were 5 cases of confirmed suicide and 1 case of potential suicide among people with epilepsy and psychiatric disorder, compared with 2 cases of confirmed suicide in people with epilepsy alone.

Study limitations were related to generalizability, the exclusion of patients with incomplete neuropsychiatric data, and the potential confounding effect of polypharmacy.

The researchers concluded “this study found that the presence of comorbid psychiatric disorders in adult [patients with epilepsy] PWE is associated with increased all-cause mortality, with a quarter of patients dying of SUDEP.”

This highlights the importance of identifying and treating psychiatric disorders in this patient population, they stated.

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures. 

Reference

Tao G, Auvrez C, Nightscales R, et al. Association between psychiatric comorbidities and mortality in epilepsy. Neurol: Clin Pract. Published online July 12, 2021. doi: 10.1212/CPJ.0000000000001114