Psychopharmacology and the Classification of Functional Psychoses 

By Thomas A. Ban and Bertalan Pethö

Four-Dimensional Classification

Affective Psychoses

Schizophrenic Psychoses

Neuroleptics and Etiological Speculations

Neuroleptics: Long-term Effects

The origin of the DA excess hypothesis of schizophrenia is in the recognition of the role of dopaminergic structures in the action mechanism of neuroleptic drugs. The PG and endorphin hypotheses are secondary elaborations and based on the assumption that schizophrenia is one disease and that the pathomechanism of this disease is related to structures which are affected by antipsychotic drugs.

On the other hand, the fact remains that neuroleptics have considerably transformed the prevailing manifestations of schizophrenic disease. While this transformation was not sufficient to significantly change the distribution of subtypes from the late 1930s to the early 1980s (Ban, Guy and Wilson, 1984a), it was sufficient to discharge patients from the hospital into the community. This, in turn, has resulted in an increase in fertile marriages among community-based schizophrenics (Erlenmeyer-Kimling et al., 1969).

Implicit in these fertility gains relevant to the general population is a small, but important shift in the structure of the gene pool. This, of course, is not expected to lead to an abrupt rise in the incidence of schizophrenia. What can be foreseen, however, is the gradual accumulation of alleles, the gradual dispersion of alleles throughout larger segments of the population and an eventual increase in the proportion of persons who may be affected.

Irrespective of its possible social consequences, long-term treatment with neuroleptics may produce serious adverse effects. While skin pigmentation occurs in less than 0.1% of all patients treated with phenothiazines for a period of two years or more (Lehmann and Ban, 1974), the estimated incidence of ocular changes is as high as 20 to 35% in patients receiving phenothiazines over an extended period. The prevalence of tardive dyskinesia, the most serious long-term complication, ranges from 0.5 to 40%  (Ban, 1979).

One possible way to reduce the occurrence of these complications is through a more discriminate use of neuroleptic drugs. While there is little, if any, evidence that patients with different types of schizophrenia, as classified by DSM-III or ICD-9, would respond differentially to neuroleptics, there are indications for differential therapeutic responsiveness to neuroleptics in Leonhard's different subtypes.