These domains are of particular interest for understanding the fundamental communication breakdown during psychotic disorders, since they can be linked to known, higher order brain systems, i.e. the language, the limbic and the motor system. These systems are anatomically and functionally separate, and their interactions are the basis for cognition and comunication. We assume that schizophrenia is due to a functional imbalance of one or more of these systems resulting in disruptions of their interaction, and to the characteristic symptoms like incoherence, paranoid anxiety or grandiosity, and movement disorders.
The psychopathological assessment is based on objective, subjective and indirect symptoms, which are assigned to the 3 domains. Each phenomenon is defined by the respective normal psychic function, and a mutually exclusive symptom pair, indicating a “positive” or “negative” deviation from normal, e.g. hyperkinesia and akinesia, logorrhea and mutism or incoherence and perplexity. Thus, the 3 domains are not categories, but dimensions, each spanning from negative to positive, and capable to represent combinations of deviations in different domains.
The scale was tested for interrater reliability and internal consistency in a group of 168 psychotic patients. The items of the scale were reliable and a principal component analysis (PCA) was best explained by a solution resembling the three candidate systems. In conclusion, the scale is apt to distinguish symptom domains related to the activity of defined brain systems. This first validation is presented in the publication cited below.
The scale was developed as a research instrument in order to investigate possible neurophysiological correlates of domain-specific psychotic syndromes. Further, the clinical utility of the scale in terms of differential pharmacology or psychotherapy is a possible research field.
The Handbook contains considerations which led to the structure of the scale in the present form. The original scale as used in a first study testing the reliability and internal consistency is presented in German and English.
- Strik, W., Wopfner, A., Horn, H., Koschorke, P., Razavi, N., Walther, S., & Wirtz, G. (2010). The Bern Psychopathology Scale for the Assessment of System-Specific Psychotic Symptoms. Neuropsychobiology, 61, 197–209. URL, DOI BibTeX