Conversion disorder, also referred to since DSM-5 as functional neurological symptom disorder is a difficult condition to understand. Over the years, much has been hypothesised about the Etiology, starting with descriptions of hysteria and trauma. The scientific focus has shifted from psychological explanations to psychological treatment of conversion disorder. The emphasis lies on the consequences of the problem and changing coping mechanisms in relation to the problem. A multifactorial stress model is being used due to the lack of empirical evidence for a causal relationship between trauma and the development of a conversion disorder. The aim of this article is to introduce a new hypothetical working model about conversion disorder. First, we present an overview of different etiological psychological explanations. Then we introduce the new hypothetical working model that still needs empirical investigation. The working model integrates both premorbid and sustaining factors and may provide leads for a transcending approach. The idea behind this is that treatment that also targets premorbid factors may be more enduring and effective.