[Folie à deux. Review of the literature and an unusual case].

We present a review of the concept's history and discuss different possible varieties of "folie à deux". Following this we report the case of a couple whose "folie à deux" has lasted for ten years. They have four of their own children and three further children from the husband's first marriage. Of special interest is the personality of the protagonists, their psychological assessment, and the so far ineffective therapeutic interventions that have been undertaken in efforts to save the children.