People do not like sudden changes and sometimes feel stress from changes. Some are more sensitive than others. During our lifetimes we have to undergo many changes. You may moved to another country and it may take 5 years to get new friends and feel at home in a new surrounding.
However what really causes schizophrenia is not yet understood but on the net you find the following suggestions:
Causes
The actual causes of schizophrenia are not fully understood.
Brain chemistry:
Abnormal functioning of neurotransmitters such as dopamine can cause schizophrenia.
Heredity:
Schizophrenia tends to run in families. If a parent has the disorder, the offsprings are susceptible to the disease.
Abnormality in the brain:
Abnormalities such as shrinkage in brain, or circuitry dysfunction can cause schizophrenia.
Complications during pregnancy and birth:
Chances of a child getting Schizophrenia are increased by infection or malnutrition during pregnancy and complications during birth such as brain injury.