Clinical High Risk for Psychosis Syndromes Among Swiss and German Youth and Young Adults: Early Identification and Intervention

Abstract

In Germany, clinical considerations of using patients’ self-reported early subtle disturbances for an early detection of developing psychosis before its first episode date back to the early twentieth century. These resulted in the formulation of the basic symptom concept that assumes that subtle, self-perceivable, but rarely externally perceivable disturbances in mental processes—the so-called basic symptoms—are the first psychopathological correlate of neurobiological processes underlying the development of psychoses, while attenuated and frank psychotic symptoms develop later in the course of the disorder as a result of inadequate coping with basic symptoms as well as other symptoms and stressors. Thus, both in Germany and Switzerland, systematic research on early detection and intervention in psychosis has mainly considered both basic symptom and ultrahigh risk criteria. Their combined consideration resulted in the first-ever staging model setting out an early and a late risk stage and, relatedly, a staged intervention model much in line with recent recommendations for intervention in a clinical high risk state by the European Psychiatric Association. Based on a first meta-analysis of single risk criteria, the basic symptom criterion cognitive disturbances and the symptomatic ultrahigh risk criteria were alternatively recommended for the detection of a clinical high risk syndrome by the European Psychiatric Association. Furthermore, research in Switzerland and Germany has focused on developmental issues and the general population, indicating that an onset-revised Attenuated Psychosis Syndromes might have clinical meaning in the general population, in particular in adults, in whom, however, it is infrequent.