Reduced gray matter volume in schizophrenia

Background: There is emerging evidence that gray matter (GM) is reduced in patients with schizophrenia. Information on the extent of global differences in the 3 principal supertentorial compartments is necessary for interpretation of regional effects. The relation of GM reduction to clinical status and neurocognition also requires examination. Methods: Magnetic resonance imaging, neurocognitive measures, and clinical assessment of symptoms and functioning were obtained for 130 patients (51 neuroleptic naive, 79 previously treated) and 130 healthy controls (75 men, 55 women in each group). Results: Overall GM volume was reduced in patients compared with controls. This was evident in men (6% reduction) and women (2% reduction) and was already evident at the first presentation of neuroleptic-naive patients. The reduction sustained correction for age and total intracranial volume. Compartmental volumes did not correlate with the severity of positive (r, -0.08 to 0.23) or negative (r, -0.01 to -0.07) symptoms, but GM volume was associated with better premorbid functioning in women (r, 0.36-0.51). Small but significant correlations (r, 0.19-0.44) were observed between GM volume and performance in 6 neurocognitive domains. These correlations varied by diagnosis, most higher in patients, and were moderated by sex. Conclusions: Gray matter volume reduction in schizophrenia is already evident in men and women at first presentation. While this reduction is not correlated with symptom severity, it is associated with cognitive performance. Since GM development accelerates in the later part of gestation, while white matter growth is primarily postnatal, the results may support the hypothesis that neurodevelopmental processes relate to GM deficit.