"Loss of brain volume associated with schizophrenia is clearly shown by magnetic resonance imaging (MRI) scans comparing the size of ventricles (butterfly shaped, fluid-filled spaces in the midbrain) of identical twins, one of whom has schizophrenia (right).  The ventricles of the twin with schizophrenia are larger.   This suggests structural brain changes associated with the illness."- Source:  Daniel Weinberger, MD, NIMH Clinical Brain Disorders Branch--used with permission