Motor, volitional and behavioural disorders in schizophrenia. 2: The 'conflict of paradigms' hypothesis.

An alternative to the conventional separation of extrapyramidal and catatonic symptoms exists in the 'conflict of paradigms' hypothesis, which proposes that there is a relative rather than absolute distinction between the two. The hypothesis predicts that a clinical association should exist between extrapyramidal and catatonic symptoms in schizophrenia. After rating 75 schizophrenic patients, a highly significant correlation between scores on the two classes of disorder was indeed found. This was composed of separate correlations between tardive dyskinesia and 'positive' catatonic phenomena, and Parkinsonism and 'negative' catatonic phenomena. The associations were not easily attributable to confounding factors and they were supported by factor analysis.