Relationship between CT scan findings and neuropsychological performance in chronic schizophrenia.

Studies relating CT abnormalities to impairments on neuropsychological tests in schizophrenic patients are critically reviewed. The overall conclusion is that there appears to be an association between CT abnormalities and neuropsychological deficits in at least some schizophrenic patient samples. It is proposed that there may be two classes of CT abnormalities in schizophrenia: "incidental" versus "essential" CT abnormalities and that neuropsychological impairment above the baseline levels found in most schizophrenic patients may be associated only with the former type. Only attempts to replicate these findings in different schizophrenic samples drawn from different settings can reveal whether this association between CT abnormalities and neuropsychological deficits is widely generalizable.