Psychogenic non-epileptic seizures (PNES) are paroxysmal changes that mimic epileptic seizures, so often misdiagnosed and treated for epilepsy. PNES are considered a psychiatric illness, personality pathology, and experiential and behavioral manifestation of depression. Despite studies over the past two decades, the pathological mechanisms of this disorder are unclear. In this paper, we critically review the current literature about the definition, epidemiology, diagnosis, treatment, related genes, and biomarkers of PNES and provide suggestions for future research. Further studies are needed for more information and knowledge on PNES to determine the appropriate psychotherapies and development of clear treatment guidelines.