Comorbid depression and associated factors in PNES versus epilepsy: Systematic review and meta-analysis

This systematic review aims to contrast levels, manifestations and associations of depression in patients with psychogenic non-epileptic seizures (PNES) and those with epilepsy.

ScienceDirect and Web of Science were searched for primary research reports describing quantitative studies involving separate epilepsy and PNES samples (age 16+) and using a validated measure of depression.

While 34 studies were identified, most were of low quality and had small sample sizes. Studies consistently found higher levels of self-reported depression in the PNES than epilepsy groups, with a meta-analysis demonstrating a significant difference between the groups. Although patients with PNES were also more likely to have a clinical diagnosis of depression than those with epilepsy, the difference between the groups was less pronounced in studies based on such diagnoses rather than self-report. Patients with PNES were more likely to report physical symptoms of depression than those with epilepsy. Interpersonal factors explained more variation in depression levels in patients with PNES than those with epilepsy, for whom illness related factors were more influential, but in both patient groups, depression had a significant impact on health related quality of life.

This systematic review demonstrates a higher prevalence of depression in patients with PNES compared to patients with epilepsy and suggests differences in the expression and possible causes of depression between these groups.