Neuropsychological frontal impairments and negative symptoms in schizophrenia

Negative symptoms have been associated with frontal lobe dysfunction in schizophrenia. However, neuropsychological studies that evaluated the correlation between performance in tests sensitive to the dorsolateral prefrontal cortex (DLPFC) and negative symptoms have shown inconsistent results. Growing evidence has appeared that not only the DLPFC but other prefrontal regions could be involved in schizophrenia. We evaluated schizophrenic patients and healthy controls using three "frontal tests": the Wisconsin Card Sorting Test (WCST), the Iowa Gambling Task (GT) and a Theory of Mind test (Faux Pas), and studied the relationship between performance in these tests and negative symptomatology. Schizophrenic patients had worse performance than normal controls on the WCST, GT and Faux Pas test. The severity of the negative symptoms showed a moderate to high correlation with performance in the Faux Pas test. Our findings support the idea that different prefrontal regions could be affected in people with schizophrenia and that the damage to each of these regions could be, at least in part, independent of the damage to the others. Some negative symptoms could be associated with frontal medial cortex dysfunction.