But in high doses, it becomes toxic, destroying neurons. In lab animals, such increases in stress hormones result in the same atrophy of the hippocampus seen in schizophrenia patients. Research with animals also has shown that when stress hormones are elevated during pregnancy, the offspring show abnormalities in the hippocampus. This might explain why parents and teachers recall schizophrenia patients being more emotionally reactive as children than their peers. But there are individual differences in how people react to stress.
Some people show a dramatic response to relatively common stressors.
Others are more resilient. We think that part of the vulnerability to schizophrenia is a heightened sensitivity to stress. During puberty, cortisol production naturally increases. Because people at risk for schizophrenia started with higher levels of stress hormones and an overly reactive stress thermostat, by the time they reach adolescence, their cortisol levels may be chronically high. This, Walker and Diforio believe, explains the temporal disjunction that has long puzzled researchers.