Differential neuropsychological patterns of frontal- and temporal-lobe dysfunction in patients with schizophrenia.

The frontal and temporal lobes have been implicated as pathogenic sites for schizophrenia, although there is a marked heterogeneity of brain function and structure between individual patients. It is currently unclear whether some patients with schizophrenia exhibit primarily frontal lobe dysfunction, while others exhibit primarily temporal-lobe dysfunction. The current investigation examined this issue in a preliminary way by using neurocognitive tests to discriminate test performances of patients with schizophrenia from patients without schizophrenia who had definitive neurological evidence of either frontal- or temporal-lobe dysfunction. Of the patients with schizophrenia, 20.7% were classified as having a frontal lobe dysfunction profile, while 19.3% had a temporal lobe dysfunction profile. Results further clarify neurobiological heterogeneity in schizophrenia by demonstrating that a substantial number of patients with schizophrenia exhibit either primarily frontal- or temporal-lobe dysfunction. Results may partially explain the inadequacy of neurobiological models for schizophrenia that do not consider these differential patterns of dysfunction.