The audience is realized to find that he has been dreaming, but the dread remains for both he father and the son. Early on in genetics was given some effect in diagnosis of schizophrenia:

In a classic 1966 paper, Leonard Heston compared foster children who were separated at birth from their schizophrenic biological mothers and foster children who were separated at birth from their psychologically healthy biological mothers. Schizophrenia appeared only in a subset (about 16%) of the children whose biological mothers had schizophrenia, a finding which suggested that rather than bad parenting, genetics plays a powerful although only partial role in the emergence of schizophrenia. (Parens, 2004)

But there are also environmental factors cited as well.

The way we perceive the world is created in large part by our nurturing environment. Highly critical parenting is one of the factors cited in those with schizophrenia as well as more serious...
[ View Full Essay]