Negative symptoms and hypofrontality in chronic schizophrenia.

Frontal lobe dysfunction is widely suspected to underlie negative symptoms of schizophrenia. This hypothesis is based largely on long-standing observations of the similarities between the effects of frontal lobe lesions and negative symptoms. However, there is little direct evidence specifically for such an association in schizophrenic patients. We measured the relationship between decreased relative prefrontal cortex glucose metabolism (hypofrontality) using positron emission tomography and evaluated the severity of negative symptoms in 20 chronic schizophrenics who underwent scanning while not receiving neuroleptic drugs. We found a close relationship between negative symptoms and prefrontal hypometabolism, particularly in the right dorsolateral convexity. This association was regionally specific. Furthermore, there was no evidence that this relationship was an artifact of age, cerebral atrophy, or severity of positive symptoms.