This article focuses on recent developments in clinical ethnopsychiatry theorized by the French psychologist Tobie Nathan, as understood and practised by a member of his clinical research team. Alongside Western psychological theories, Nathan’s approach sets out to include, within its clinical research setting, cultural and religious theories and healing practices related to unhappiness and disease. All such theories, regardless of the culture or civilization they belong to, are regarded as potentially valid and also as possible therapeutic tools. In this perspective, Nathan criticizes the concepts of representation or belief and prefers to talk about objects and theories. To illustrate his unique approach to therapy, the treatment of a Cameroon immigrant teenager and her family, conducted at the University clinic founded by Nathan, is extensively presented in this article.