Retinitis pigmentosa and schizophrenia

There have been previous suggestions in the literature of a link between schizophrenia and retinitis pigmentosa (RP) or its associated syndromes. In this article, we describe two cases of schizophrenia and two cases of delusional disorder occurring in patients with RP. We explore possible reasons for an association between RP and schizophrenia including shared genetic predisposition, sensory deprivation, coarse brain disease and retinoid dysregulation. Awareness of an association may help to direct future research into the aetiology of these disorders, especially in the areas of neurochemistry and medical genetics. (C) 1998 Elsevier, Paris.