Abstracts

Rationale: Epilepsy affects ~3 million adults in the United States, with 30%-60% experiencing focal onset seizures (FOS). Considerable morbidity, mortality, and reduced quality of life (QoL) are associated with FOS. A targeted literature review (TLR) was conducted to understand comorbidity burden in FOS.

Methods: We conducted a TLR of Medline and EMBASE spanning the last 10 years (2013 to present), focusing on comorbidities in adult patients with FOS. English-language studies meeting predefined criteria were reviewed. A dual-review process assessed 10% of citations for quality. A supplementary manual search was also used to identify further relevant publications.

Results: The TLR identified 13 studies examining comorbidities in FOS (10 sourced from literature databases, 3 from manual searches). Study designs of the included publications were predominantly retrospective (n=5) and cross-sectional (n=4), with few prospective (n=2), case-control (n=1), and systematic review (n=1). Studies were mostly conducted in Europe (n=6) and the US (n=6). Multiple studies investigated the impact of comorbidities on seizure efficacy/occurrence (n=5), economic burden (n=4), QoL (n=4), and adherence (n=1), revealing that comorbidities in FOS are linked with increased burden. Specifically, these studies observed increased costs for patients with FOS who have comorbidities compared to those without. Patients with FOS who suffer from comorbid depression and/or insomnia experienced worse QoL. Findings varied on the influence of comorbid anxiety (n=4). One study found increased health care utilization among patients with FOS who had comorbid mental health conditions encompassing anxiety, attention-deficit conduct disorder, bipolar disorder, major depression, schizophrenia, and other psychotic conditions. Of the 13 studies identified in this TLR, 10 studies reported mental health comorbidities, showing varied effects on seizure efficacy outcomes. Depression (n=7), anxiety (n=3), mental health or psychiatric comorbidity/condition (n=3), and suicidality (n=1) were the most common comorbid mental health conditions reported. Three studies reported that patients with FOS and mental health comorbidities, particularly depression, had worse seizure efficacy outcomes compared to those without depression; one study reported patients with depression scored significantly worse on measures of seizure severity, one study reported the odds of failing to achieve 1-year seizure freedom were significantly higher in patients with depression, and one study reported any presence of a mental health comorbidity was significantly associated with increased seizure-related healthcare resource use.


Conclusions: This TLR demonstrated that mental health comorbidities in patients with FOS amplify clinical, economic, and humanistic burden, especially in those with depression. Understanding the association between mental health comorbidities, like depression, and FOS burden is vital for tailored interventions and improved patient outcomes.

Funding: This study was funded by Xenon Pharmaceuticals Inc.