Melbourne School of Psychological Sciences - Theses

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    Neuropsychological and computed tomography findings in two subgroups of schizophrenia
    Clausen, Margaretha Helen ( 1986)
    The group of disorders collectively referred to as schizophrenia, have traditionally been conceptualized as functional psychoses in which primary cognitive functions are unimpaired. Despite this, a proportion of schizophrenic patients have long been known to perform poorly on tests of cognitive function and some proceed to an end state resembling organic dementia. The application of CT scans in the last decade to the schizophrenic population, has revealed that some schizophrenic patients have abnormal brain morphology. Changes in brain morphology have also been correlated with cognitive impairment and defect (negative) symptoms. On the basis of these findings two subgroups of schizophrenia have been proposed. Type I schizophrenia is hypothesized to be characterized by normal brain morphology, normal cognition and florid (positive) symptoms. Type II schizophrenia is hypothesized to be characterized by abnormal brain morphology, impaired cognition and predominantly defect (negative) symptoms. Despite the heuristic value of this hypothesis, research was impeded by the lack of valid techniques for the measurement of positive and negative symptoms. Recent reports have provided such measurement scales, however these have not been widely used to specifically investigate CT scan findings and cognitive impairment in schizophrenic patients. This is the report of an investigation which aimed to examine the relationship between positive and negative symptoms, CT scan findings and performance on a wide range of neuropsychological tests known to be sensitive to the effects of localized cerebral disruption in neurological patients 1 in a group of schizophrenic patients. The results suggest that patients with severe negative symptoms have localized cerebral atrophy of the frontal regions of the brain and are impaired on tests of frontal lobe function. These findings support the hypothesis of different subgroups of schizophrenia, in which the underlying aetiology of one subgroup, may be organic in nature.