Nineteen studies, with a total of 331 patients and 309 controls, were included in the review.
Fourteen studies found reduced FA in patients compared with control individuals.
Two studies found a loss of normal asymmetry in patients.
One of the 6 VBA studies (two analysing whole brain and four specific regions) reported no significant differences between patients and controls; the other studies reported widespread differences (2 studies), reduced FA in the splenium and forceps major but not other areas (1 study), extensive reductions in FA (including areas of the genu and splenium), and reduced FA in the left arcuate (1 study).
The ROI varied across studies. When studies were considered by ROI, no consistent difference between schizophrenic patients and controls was apparent.
For studies that defined ROIs that included the corpus callosum as well as whole brain studies (n=8), 4 studies found reduced FA in patients compared with controls and 4 studies found no difference.
For studies that defined ROIs that included the cingulum bundle as well as whole brain studies (n=9), 4 studies found reduced FA in patients compared with controls and 5 studies found no difference.