Comorbidities of epilepsy: Results from the Epilepsy Comorbidities and Health (EPIC) survey

Purpose: To estimate the prevalence of neuropsychiatric and pain disorders in adults with epilepsy in the United States. Methods: In 2008, an 11-item survey including validated questions to screen for a lifetime history of epilepsy was mailed to 340,000 households from two national panels selected to be generally representative of the noninstitutionalized U.S. population. Information on epilepsy and other disorders was collected from 172,959 respondents aged 18 or older. Propensity scoring was used to match respondents with and without epilepsy on baseline characteristics and risk factors for epilepsy. Prevalence ratios (PRs) of comorbidities in respondents with epilepsy were calculated using log-binomial generalized linear models. Comorbidities were categorized as neuropsychiatric (anxiety, depression, bipolar disorder, attention-deficit/hyperactivity disorder, sleep disorder/apnea, and movement disorder/tremor), pain (migraine headache, chronic pain, fibromyalgia, neuropathic pain), and other (asthma, diabetes, and high blood pressure). Key Findings: Two percent (3,488) of respondents reported ever having been told they had epilepsy or a seizure disorder. Respondents with self-reported epilepsy were more likely (p < 0.001) than those without epilepsy to report all six neuropsychiatric disorders (PR from 1.27-2.39), all four pain disorders (PR 1.36-1.96), and asthma (PR 1.25). Significance: Neuropsychiatric conditions and pain disorder comorbidities were reported more often in individuals with self-reported epilepsy than in those without epilepsy. Identification of these conditions is an important consideration in the clinical management of epilepsy.