A preliminary study of the neuropsychological heterogeneity of familial schizophrenia.

This exploratory study describes the heterogeneity of the neuropsychological deficits that characterize familial schizophrenia. Forty-six familial schizophrenics showed significantly more variability in abstraction and problem-solving and motor control than 39 non-familial schizophrenics. Cluster analyses of these two neuropsychological parameters indicate that while the non-familial schizophrenics fall into one homogeneous cluster, the familial schizophrenics fall into three relatively distinct clusters which differ significantly in their morbid risk for schizophrenic-spectrum disorder. These preliminary data suggest that frontal lobe deficits are associated with an increased familial risk for schizophrenia.