Atypical psychosis in relation to the schizophrenia spectrum: Report of a family and review of the literature

Abstract

The genetic concepts of genotypes, phenotypes, and phenocopies, when put into use in psychiatry, could offer a new perspective that needs to be validated or invalidated by future research. The sharing of a common genotype or genotypes by distinct phenotypes underlies the basic concept of schizophrenia spectrum. In this article, the following hypothesis will be considered: Certain “atypical” psychotic conditions, sometimes difficult to distinguish clinically and by family histories from mania, may share a common genotype or genotypes with “typical” schizophrenia. In other words can the schizophrenia spectrum include phenocopies of manic states? The pedigree method has been used extensively in the study of schizophrenic disorders but no mode of transmission, Mendelian or other type, has been demonstrated. 1,2 Despite this negative result, the pedigree method can offer insight into the relationship of the different types of psychosis when they occur in the same family. This report is about a family in which the proband had a “manic-depressive-like” disorder. Her initial diagnosis was that of a schizo-affective disorder, but 16 months after her first admission she displayed and experienced manic signs and symptoms. She was placed on Lithium carbonate and a four month follow-up on this drug has shown her to be asymptomatic. The proband's sister has a schizophrenic disorder. The case histories of each affected member are summarized.