To what degree does environment govern the severity of symptoms in schizophrenia? From what I understand about the physiology of schizophrenia it is thought to be caused by chemical imbalances resulting from genetic factors, fueled by environmental factors. I've garnered that environmental factors can play a large role in how a person reacts to the disease.

As an example: a person with a genetic predisposition towards schizophrenia is raised in an abusive household with his parents yelling everyday, they will definitely become angry and more stressed out, which one might assume would lead to their eventual psychotic break. Is this 100% correct? Another person who might be less stressed out, probably raised in a normal family, could potentially experience troubling symptoms before a complete psychotic break. Is this a valid assumption or observed pattern in those who suffer from the disease?

So, if environmental factors can contribute to the onset of schizophrenia, could the removal of these factors lessen the symptoms? Take for example Jared Loughner, he will be spending life in prison. With time away from society, with the stresses of life removed, and (given the correct medication), could incarcerated schizophrenia patients' symptoms be ameliorated by this change in social situation?  

Any info on this?
I think reading about the genain quadruplets should give you a clear idea of the effect of environment on schizophrenia. Basically, the quadruplets had a genetic disposition to this disorder and all 4 siblings were admitted at some point or another to the National Institute of Mental Health as schizophrenic. However, there were differences in the severity of the disorder in all 4 siblings due to the way they were treated by their parents, showing that despite genetic dispositions to a disorder, environmental factors do affect the severity of it.