Description and distribution of the subtypes of chronic schizophrenia based on Leonhard's classification.

Prior to the introduction of neuroleptics a lack of interest in complex classifications of the chronic schizophrenias was due to the lack of effective treatment. With the recognition of neuroleptic response heterogeneity, and of the hazards of long-term neuroleptic administration, interest in subtype classification such as that of Leonhard has grown. A simplification of the Leonhard scheme is presented. The first distinction drawn is between systematic or process schizophrenia and nonsystematic or episodic schizophrenia. Both groups are further subdivided according to whether the symptomatology is dominated by cognitive, affective or motor features. In the case of the systemic schizophrenias, further subdivision of the 3 major types is made on the basis of both severity and specific symptom characteristics. If such a scheme were a natural or biologically-based classification, rather than merely an artificial subdivision of schizophrenia, one might expect that similar proportions of the different subtypes would be found in independently selected samples. Preliminary data composing subtype proportions in Leonhard's original group, a population reported by Astrup, and a recently obtained international sample are presented. Some significant correlations between the samples are observed, and despite methodological short comings, the similarities in the distribution of subtypes across time and across countries give some support to Leonhard's taxonomy.