Objective:Knowledge regarding psychiatric disorders in children and adolescents with psychogenic nonepileptic seizures (PNES) is limited. This study outlines the spectrum and risk of psychiatric disorders in childhood-onset PNES.Methods:A nationwide matched cohort study of children and adolescents with PNES aged 5-17 years at time of diagnosis between January 1, 1996 and December 31, 2014. Two matched comparison groups were included: children and adolescents with epilepsy (ES), and children and adolescents without PNES or epilepsy, termed healthy controls (HC). Outcomes were prevalent psychiatric disorders prior to index (i.e. date of diagnosis or corresponding date for HCs), and incident psychiatric disorders two years after index. Relative risks (RRs) were calculated and adjusted for potential confounders.Results:We included 384 children and adolescents with validated PNES, 1,152 with epilepsy, and 1,920 healthy controls. Among the PNES cases, 153 (39.8%) had prevalent psychiatric disorders and 150 (39.1%) incident psychiatric disorders. As compared to the epilepsy and healthy controls, children and adolescents with PNES had elevated risks of both prevalent psychiatric disorders (adjusted RRPNES/ES: 1.87, 95% CI: 1.59–2.21, adjusted RRPNES/HC: 5.54, 95% CI: 4.50–6.81), and incident psychiatric disorders (adjusted RRPNES/ES: 2.33, 95% CI: 1.92–2.83, adjusted RRPNES/HC: 8.37, 95% CI: 6.31–11.11). A wide spectrum of specific psychiatric disorders displayed elevated RRs.Conclusions:Children and adolescents with PNES are at higher risk of a wide range of psychiatric disorders as compared to children and adolescents with epilepsy and healthy controls. A careful psychiatric evaluation is warranted to optimize and individualize treatment.