Pharmacopsychiatry and iatrogenic Parkinsonism

Through the study of the pharmacological and clinical actions of chlozapine, a new drug used in psychiatry, we are questioning one of the traditional statements on the therapeutic action of antipsychotics: the affirmation that those must have, concomitantly, antipsychotic action and intense extrapyramidal effects (drug-induced parkinsonism). Combining our own investigations and those of other authors, the generally accepted concepts on the possible biochemical mechanisms involved in the etiology of endogenous psychosis are criticized. Although there is evidence of alterations of the dopaminergic system in schizophrenia and also changes due to the action of neuroleptics, we cannot reject, given the dissociation of effects obtained with chlozapine, the possibility that the repercussion on the nigrostriatal dopaminergic system be only one of the many probably mechanisms of action of psychotropic drugs. Thus, such anatomical and neurochemical systems could be involved only in a secondary manner in the biochemical alterations typical of schizophrenia.