- Samy Egli: Institute of Psychology, Applied Cognitive Psychology, University of Zurich, Binzmühlestrasse 14/28, Zurich 8050, Switzerland.
BACKGROUND: In the current debate about the categorical or dimensional classification of mental disorders many fruitful methods to illustrate one or the other aspect are employed, and suggestions are made to combine the two perspectives.
METHODS: We present such an approach to combine both perspectives at the same time. Based on psychopathological AMDP-symptom profiles, a map of psychiatric patients was calculated by robust nonmetric multidimensional scaling (NMDS).
RESULTS: The sample from the Ludwig-Maximilians University in Munich included the records of patients, who were admitted and discharged in 2002 and 2003 with a diagnosis of either paranoid schizophrenia, (F20.00, N = 24), bipolar affective disorder, current episode manic without psychotic symptoms (F31.1, N = 32) or severe depressive episode without psychotic symptoms (F32.2, N = 78). In the resulting map of patients we found a clear categorical distinction according to the diagnostic groups, but also high regression values of AMDP-syndromes (manic syndrome: r = 0.83, depressive syndrome: r = 0.68, and paranoid-hallucinatory syndrome, r = 0.62).
DISCUSSION: The map of psychiatric patients presents an approach to consider the categorical and dimensional aspects at the same time. We were able to identify meaningful delineations between diagnostic clusters as well as continuous transitions. This method allows the whole psychopathological profile of each individual patient to be considered and also to identify misdiagnosed cases at a glance.