To define the prevalence of psychiatric symptoms of anxiety and depression in patients at the time of their first seizure presentation to a neurologist.
Our pilot study uses a cohort approach with multimodal data (clinical, social, structural [3T magnetic resonance imaging], and functional [electroencephalogram]). We screened 105 patients referred to the Halifax First Seizure Clinic between 2014 and 2016 and 51 controls. All participants completed two screening questionnaires: Neurological Disorders Depression Inventory for Epilepsy and Generalized Anxiety Disorder 7-Item. After applying the exclusion criteria, the study population consisted of 57 patients with unprovoked first seizure and 31 controls. The prevalence of anxiety and depression was based on cutoff scores of >15 and >14 respectively.
Unprovoked first seizure patients showed higher prevalence of depression (33%) compared with control (6%) with an odds ratio (OR) of 2.75 (95% confidence interval [CI], 0.72-10.5). There was no significant difference in the prevalence of anxiety between control subjects (9.7%) and unprovoked first seizure patients (23%). Subcategory analysis conducted after diagnosis confirmation revealed significantly increased OR of depression in patients diagnosed with new-onset epilepsy (OR, 11.6; 95% CI, 2.1-64.0) and newly diagnosed epilepsy (OR, 20.0; 95% CI,2.2-181), but not first seizure only patients (OR, 2.2; 95% CI,0.28-17.6) compared with control.
Our study supports a bidirectional relationship between the first seizure and depression. Prevalence rate of depression increased with duration of undiagnosed epilepsy at the time of first clinical assessment.