The Cross-Sectional and Longitudinal Architecture of Schizophrenia: Significance for Diagnosis and Intervention?

Abstract

In the course of revising the current psychiatric classification systems, one of the major questions relates to the classification of schizophrenia. While cross-sectional issues of the pathogenesis of schizophrenia are duly reviewed in other chapters of this book, recent discussions have put aspects of the longitudinal time course of schizophrenia into their focus. Considering the onset of schizophrenia, initial prodromal symptoms have been characterized but yet yield a low sensitivity and specificity with progression rates to full-blown schizophrenia or “psychosis” in general (including affective disorders) ranging from approximately 15 to 40% in different studies. Thus, the question arises whether such findings warrant the inclusion of a novel “prodromal state” into the mental disorders chapter of the International Classification of Diseases (11th revision, hence ICD-11) or the Diagnostic and Statistical Manual issued by the American Psychiatric Association (5th revision, hence DSM-V). What may be the new diagnostic and therapeutic strategies to be employed in the obviously prognostically very important early stages of schizophrenia? Once schizophrenia has fully developed, cognitive dysfunctions like reduced attention and impairments of working memory play a major role in the determination of the further disease course in particular considering functional disabilities.