Other studies show neurons that are abnormally large, and malformation of the myelin, a fatty substance that insulates neurons and allows electrical impulses to travel along neurons more efficiently and effectively (Bower, 1996).
At the same time, several twin studies point to a strong genetic component. The exact mechanism is not known, but a number of mental illnesses and neurochemical disorders appear to have genetic tendencies (Bower, 1996), (Ratey, 2001).
In identical twin studies, when one twin develops schizophrenia, the other twin develops it about 50% of the time (Bower, 1996). In some of those studies, the twin who developed schizophrenia showed damage to the brain not related to the schizophrenia (Bower, 1996). This provides strong support for the Vulnerability model, because it suggests that the twin who developed schizophrenia may have done so because of the additional brain