The authors used positron computed tomography (CT) and 11C-labeled glucose to measure brain glucose utilization in 20 chronic schizophrenic patients (18 men, 2 women, mean age 38) and 5 male control subjects (mean age 38). Positron emission tomography (PET) revealed at least three subtypes: hypofrontal (type A), hypoparietal (right-sided disturbance in right-handed and left-sided disturbance in left-handed patients) (type B), and normal (type C). The significant count reduction in the frontal lobe (Brodmann's area 10) in type A patients was 38%, while that in the parietal lobe (Brodmann's area 40) in type B patients was 26% in each lobe of the brain.